AFAP1L1 (Actin Filament-Associated Protein 1-Like 1): A Comprehensive Review

Introduction

AFAP1L1 (Actin Filament-Associated Protein 1-Like 1; UniProt: Q8TED9) is a human adaptor protein that functions as a critical regulator of actin cytoskeleton dynamics and cell invasion. Originally identified through a homology search of the human genome using the pleckstrin homology (PH) domain sequences of AFAP1, AFAP1L1 was recognized as the third member of the actin filament-associated protein (AFAP) family, which also includes AFAP1 (AFAP-110) and AFAP1L2 (XB130) [snyder-2011-afap1l1-invadosomes-abstract]. The gene is located on chromosome 5q33.1 and consists of 19 exons encoding a 768 amino acid protein with approximately 44% sequence identity to AFAP1 [snyder-2011-afap1l1-invadosomes-abstract].

As a non-enzymatic adaptor protein, AFAP1L1 does not catalyze biochemical reactions. Instead, it serves as a scaffold that links different components of cellular signaling complexes through multiple protein-binding motifs, thereby orchestrating cytoskeletal reorganization in response to upstream signals. The primary function of AFAP1L1 is to integrate signals from Src family tyrosine kinases and translate them into changes in actin cytoskeleton architecture, particularly at specialized actin-rich structures called invadosomes [tie-2016-sarcoma-invadopodia-abstract]. This function is essential for cell migration, invasion, and the formation of podosomes and invadopodia, making AFAP1L1 particularly relevant to cancer metastasis and pathological angiogenesis.

Protein Structure and Domain Organization

AFAP1L1 possesses a characteristic modular domain architecture that enables its function as a signaling scaffold at the interface of actin dynamics and signal transduction. The protein contains several conserved domains shared with other AFAP family members, as well as unique features that confer distinct binding specificities [snyder-2011-afap1l1-invadosomes-abstract][xia-2016-xb130-adaptor-abstract].

The N-terminal region of AFAP1L1 contains a single SH3 binding motif with the sequence DLPPPLPNKP, which differs significantly from the dual SH3 binding motifs found in AFAP1 [snyder-2011-afap1l1-invadosomes-abstract]. This sequence variation is functionally significant: while AFAP1's SH3 binding motif preferentially interacts with the SH3 domain of the non-receptor tyrosine kinase cSrc, the AFAP1L1 SH3 binding motif exhibits approximately 9-fold higher affinity for cortactin's SH3 domain compared to cSrc [snyder-2011-afap1l1-invadosomes-abstract]. This preferential cortactin binding distinguishes AFAP1L1 from AFAP1 and suggests specialized functions in cortactin-dependent processes such as invadosome formation.

Two pleckstrin homology (PH) domains are positioned centrally within the protein, flanking a serine/threonine-rich region. These PH domains bind phosphoinositide lipids, particularly those generated at the plasma membrane by phosphoinositide 3-kinase (PI3K), enabling membrane recruitment and spatial regulation of AFAP1L1 function [tie-2016-sarcoma-invadopodia-abstract]. The PH domains of AFAP family members show high sequence conservation and form characteristic beta-barrel structures that mediate lipid interactions [snyder-2011-afap1l1-invadosomes-abstract].

The protein also contains two SH2 binding motifs that serve as docking sites for SH2 domain-containing proteins. Phosphorylation of tyrosine residues within these motifs creates binding sites for downstream effectors. Specifically, phospho-tyrosine 136 (pY136) binds the SH2 domain of Vav2, a guanine nucleotide exchange factor for Rho GTPases, while phospho-tyrosine 566 (pY566) binds the SH2 domain of Nck2, an adaptor protein that recruits actin-nucleating complexes [tie-2016-sarcoma-invadopodia-abstract].

The C-terminal region contains a leucine zipper motif that mediates intra- and inter-molecular interactions, enabling AFAP1L1 dimerization or multimerization, as well as a putative actin-binding domain that allows direct association with filamentous actin [snyder-2011-afap1l1-invadosomes-abstract]. This actin-binding capability is essential for AFAP1L1's localization to stress fibers and invadosomes.

Subcellular Localization and Invadosome Association

AFAP1L1 localizes to specific subcellular compartments associated with dynamic actin structures, particularly invadosomes. Invadosomes is a collective term for podosomes (found in normal cells such as macrophages, osteoclasts, and smooth muscle cells) and invadopodia (found in cancer cells), which are actin-rich membrane protrusions specialized for extracellular matrix (ECM) degradation and cellular invasion [snyder-2011-afap1l1-invadosomes-abstract].

Fluorescence microscopy studies have demonstrated that AFAP1L1 decorates actin stress fibers and concentrates at punctate actin structures where it colocalizes with cortactin, a hallmark of invadosome localization [snyder-2011-afap1l1-invadosomes-abstract]. Upon overexpression in A7r5 rat aortic smooth muscle cells, AFAP1L1 can induce podosome formation without external stimulation, indicating that elevated AFAP1L1 levels are sufficient to trigger the cytoskeletal reorganization required for podosome assembly [snyder-2011-afap1l1-invadosomes-abstract].

In cancer cells, AFAP1L1 localizes to invadopodia, where it plays a critical role in regulating the machinery required for ECM degradation and cellular invasion. Studies in osteosarcoma cell lines have shown that AFAP1L1 knockdown disrupts invadopodia formation and inhibits phosphorylated myosin light chain 2 (MLC2) recruitment to filamentous actin structures [tie-2016-sarcoma-invadopodia-abstract]. This disruption impairs cell attachment, migration, and invasive capacity.

Immunohistochemical analysis of human tissues reveals differential expression patterns between AFAP1L1 and AFAP1. In breast tissue, AFAP1L1 is expressed in the contractile myoepithelial cell layer surrounding breast ducts and in the microvasculature [snyder-2011-afap1l1-invadosomes-abstract]. In colon, expression is detected in the mucous membrane, colonic crypts, and smooth muscle cell layer. Notably, AFAP1L1 shows unique expression in neuronal structures, particularly the dentate nucleus and Purkinje cell layer of the cerebellum, where it localizes along neuronal processes rather than cell bodies—a pattern distinct from AFAP1 [snyder-2011-afap1l1-invadosomes-abstract]. This tissue distribution suggests specialized functions in neuronal signaling and motor coordination pathways.

Molecular Function and Signaling Mechanisms

AFAP1L1 functions as a signaling hub that integrates upstream kinase signals and translates them into coordinated cytoskeletal changes. The protein operates through phosphotyrosine-dependent mechanisms that link Src family kinase activation to actin dynamics regulation [tie-2016-sarcoma-invadopodia-abstract].

The interaction between AFAP1L1 and cortactin is central to its function. Cortactin is an actin nucleation-promoting factor that activates the Arp2/3 complex to initiate branched actin network formation. By preferentially binding cortactin through its SH3 binding motif, AFAP1L1 positions itself at sites of active actin polymerization where it can coordinate additional signaling inputs [snyder-2011-afap1l1-invadosomes-abstract].

Phosphorylation of AFAP1L1 by Src family kinases, particularly Lyn, creates docking sites for downstream effectors. The pY136-Vav2 interaction is particularly important, as Vav2 is a guanine nucleotide exchange factor (GEF) that activates Rho family GTPases including Rac and CDC42 [tie-2016-sarcoma-invadopodia-abstract][sun-2023-gastric-vav2-cdc42-abstract]. Through Vav2, AFAP1L1 regulates Rac activity and controls the downstream PAK1/2/3 (p21-activated kinases) pathway, which phosphorylates MLC kinase and MLC2 to regulate actomyosin contractility [tie-2016-sarcoma-invadopodia-abstract].

The pY566-Nck2 interaction provides an alternative signaling output by recruiting actin-nucleating complexes to sites of AFAP1L1 localization. Nck2 (also known as NCKβ or Grb4) is an adaptor protein that links receptor tyrosine kinases to downstream actin regulators including N-WASP and the Arp2/3 complex [tie-2016-sarcoma-invadopodia-abstract].

In gastric cancer cells, AFAP1L1 activates a specific signaling cascade involving VAV2, CDC42, and integrin α5 (ITGA5). Co-immunoprecipitation experiments confirmed the physical interaction between AFAP1L1 and VAV2, and demonstrated that this interaction activates CDC42 GTPase activity. Activated CDC42 promotes ITGA5 expression at the transcriptional level, leading to activation of integrin signaling through focal adhesion kinase (FAK) and ERK pathways [sun-2023-gastric-vav2-cdc42-abstract]. This signaling axis drives epithelial-to-mesenchymal transition (EMT) characterized by decreased E-cadherin and increased vimentin expression.

Role in Cell Migration and Invasion

AFAP1L1 plays a critical role in regulating cell migration and invasion, processes that require dynamic remodeling of the actin cytoskeleton. The protein's function in these processes has been extensively characterized in cancer cells, where elevated AFAP1L1 expression promotes invasive behavior [tie-2016-sarcoma-invadopodia-abstract][sun-2023-gastric-vav2-cdc42-abstract].

Studies in sarcoma cells demonstrated that AFAP1L1 can transform cells and promote migration when co-expressed with active Lyn kinase. This co-expression profoundly influences cell morphology and movement, indicating that AFAP1L1 translates Src family kinase signals into morphological changes required for motility [tie-2016-sarcoma-invadopodia-abstract]. Conversely, knockdown of AFAP1L1 in osteosarcoma cell lines inhibits cell attachment, migration, and invasion, accompanied by disruption of invadopodia formation and impaired MLC2 phosphorylation at actin structures [tie-2016-sarcoma-invadopodia-abstract].

In gastric cancer cells, AFAP1L1 promotes proliferation, migration, and invasion in vitro, and enhances tumor growth and metastasis in vivo. These effects are mediated through the VAV2-CDC42-ITGA5 signaling axis and the induction of EMT [sun-2023-gastric-vav2-cdc42-abstract]. The functional importance of CDC42 activation is highlighted by experiments showing that ML141, a selective CDC42 GTPase inhibitor, can prevent tumor progression in cells with high AFAP1L1 expression.

Beyond cancer, AFAP1L1's actin cross-linking function has been shown to provide a physical barrier against Trypanosoma cruzi invasion. Knockdown of AFAP1L1 in host cells induces softening of actin filaments and facilitates parasite cell invasion and intracellular multiplication, demonstrating that AFAP1L1-mediated cytoskeletal integrity can function as a host defense mechanism [araujo-2016-trypanosoma-cruzi-abstract].

Role in Angiogenesis and the YAP-DLL4-NOTCH Pathway

Recent research has identified AFAP1L1 as a regulator of pathological angiogenesis through a mechanism involving the YAP-DLL4-NOTCH signaling axis. This function extends AFAP1L1's significance beyond cancer cell invasion to include endothelial cell biology and blood vessel formation [ren-2023-hypoxia-neovascularization-abstract].

AFAP1L1 expression correlates positively with hypoxia signaling across multiple cancer types. Under hypoxic conditions, hypoxia-inducible factor 1 alpha (HIF-1α) directly activates AFAP1L1 transcription by binding to hypoxia response elements in the AFAP1L1 promoter [ren-2023-hypoxia-neovascularization-abstract]. This establishes AFAP1L1 as a hypoxia-responsive gene with potential roles in tumor adaptation to low oxygen environments.

Mechanistically, AFAP1L1 inhibits YAP phosphorylation, promoting YAP nuclear translocation where it suppresses DLL4 (Delta-like ligand 4) expression. DLL4 is a key ligand for Notch receptors, and reduced DLL4 expression alters Notch signaling in endothelial cells, leading to increased tip cell sprouting and angiogenesis [ren-2023-hypoxia-neovascularization-abstract]. When AFAP1L1 is knocked down, YAP becomes hyperphosphorylated and retained in the cytoplasm, resulting in increased DLL4 expression, enhanced Notch activation, and suppressed angiogenic sprouting.

Studies using endothelial cell-specific AFAP1L1 conditional knockout mice demonstrated that AFAP1L1 deletion reduces tumor growth and blood vessel formation. In three different models of ocular pathological neovascularization—oxygen-induced retinopathy, laser-induced choroidal neovascularization, and suture-induced corneal neovascularization—AFAP1L1 inhibition significantly reduced abnormal blood vessel formation [ren-2023-hypoxia-neovascularization-abstract]. These findings suggest AFAP1L1 as a potential therapeutic target for both solid tumors and neovascular eye diseases, offering an alternative to anti-VEGF therapies that face issues with drug resistance.

As an actin-associated protein, AFAP1L1 also influences endothelial cell morphology and filopodia formation, structures critical for directed cell migration during vessel sprouting. This cytoskeletal function may complement the YAP-DLL4-NOTCH signaling mechanism in regulating angiogenesis.

Role in Cancer

AFAP1L1 has emerged as a significant factor in cancer biology, with elevated expression associated with tumor progression and poor prognosis across multiple cancer types. Unlike AFAP1 and AFAP1L2/XB130, AFAP1L1 shows consistent upregulation in several malignancies, positioning it as a potential biomarker and therapeutic target [sun-2023-gastric-vav2-cdc42-abstract][zhang-2018-lung-cancer-abstract].

In gastric cancer, systematic analysis of the AFAP family revealed that AFAP1L1 is the only family member significantly upregulated compared to normal gastric tissues. Elevated AFAP1L1 expression predicts poor prognosis and serves as an independent risk factor for patient survival [sun-2023-gastric-vav2-cdc42-abstract]. The protein promotes gastric cancer progression through the VAV2-CDC42-ITGA5 signaling pathway, driving EMT and enhancing invasive and metastatic potential.

In non-small cell lung cancer (NSCLC), AFAP1L1 functions as an oncogenic factor. Knockdown studies in A549 lung cancer cells demonstrated that AFAP1L1 depletion significantly inhibits cell cycle progression, increases apoptosis, and attenuates cell growth [zhang-2018-lung-cancer-abstract]. Mechanistically, AFAP1L1 knockdown triggers activation of p38 MAPK, decreases PRAS40 phosphorylation, and increases caspase-3 cleavage, indicating activation of stress response and apoptotic pathways. These findings suggest AFAP1L1 may serve as both a prognostic marker and therapeutic target in NSCLC.

In sarcomas, AFAP1L1 regulates cell migration, invasion, and invadopodia formation through phosphotyrosine-dependent pathways involving Lyn kinase, Vav2, and Nck2 [tie-2016-sarcoma-invadopodia-abstract]. The protein's ability to transform cells and promote migration when co-expressed with active kinases highlights its oncogenic potential in mesenchymal malignancies.

The angiogenesis-promoting function of AFAP1L1 through the YAP-DLL4-NOTCH axis adds another dimension to its role in cancer. By promoting tumor neovascularization under hypoxic conditions, AFAP1L1 may contribute to tumor growth and progression beyond its cell-autonomous effects on invasion and metastasis [ren-2023-hypoxia-neovascularization-abstract].

Transcriptional Regulation

The transcriptional regulation of AFAP1L1 expression has been characterized, providing insight into how this gene is controlled in normal and pathological contexts. The proximal promoter region of AFAP1L1 contains tandem specificity protein (Sp) binding motifs at positions -86 to -76 that are essential for transcriptional activity [kajita-2012-sp3-transcription-abstract]. While both Sp1 and Sp3 transcription factors can activate the AFAP1L1 promoter in vitro, chromatin immunoprecipitation experiments demonstrated that Sp3 is the major transcription factor binding to the proximal promoter in AFAP1L1-positive cells [kajita-2012-sp3-transcription-abstract].

Treatment with mithramycin A, which inhibits Sp protein binding to GC-rich DNA sequences, effectively blocks Sp3 binding and reduces AFAP1L1 expression in a dose-dependent manner. Furthermore, siRNA knockdown of Sp3 significantly reduces AFAP1L1 expression and decreases cell invasion and migration in osteosarcoma cells [kajita-2012-sp3-transcription-abstract]. Sequence alignment of the 5'-flanking region of the AFAP1L1 gene across human, mouse, and rabbit revealed conserved Sp-binding sites, suggesting that this regulatory mechanism is evolutionarily maintained across mammals.

In addition to Sp3-mediated basal transcription, AFAP1L1 expression is regulated by hypoxia through HIF-1α. Under hypoxic conditions, HIF-1α directly activates AFAP1L1 transcription by binding to hypoxia response elements in the promoter [ren-2023-hypoxia-neovascularization-abstract]. This dual regulation—by Sp3 for basal expression and HIF-1α for hypoxia-induced expression—positions AFAP1L1 at the intersection of constitutive cellular functions and stress-responsive pathways.

Evolutionary Conservation and Mouse Models

AFAP1L1 is evolutionarily conserved across vertebrates, with stringent orthologs identified in mouse (Afap1l1), rat, and zebrafish. The mouse ortholog (MGI:2147199) is located on chromosome 18 and shows high sequence conservation, particularly in the functionally critical domains including the PH domains, SH3 binding motif, and actin-binding region. Conservation of the Sp-binding sites in the promoter region across human, mouse, and rabbit further indicates functional conservation of transcriptional regulation [kajita-2012-sp3-transcription-abstract].

Mouse knockout studies have been instrumental in understanding AFAP1L1 function in vivo. The International Mouse Phenotyping Consortium (IMPC) has generated Afap1l1 knockout mice, with multiple alleles available including gene-trapped and targeted mutations. Interestingly, initial phenotyping of Afap1l1 knockout mice across 15 physiological systems revealed no significant overt phenotypes, suggesting either functional redundancy with other family members or that phenotypes may be context-dependent and manifest under specific challenges such as tumor development or wound healing.

More informative in vivo studies have employed tissue-specific knockdown approaches. Endothelial cell-specific AFAP1L1 knockdown using adeno-associated virus (AAV) vectors under control of the TIE promoter demonstrated that AFAP1L1 depletion in endothelium significantly reduces tumor growth and volume, decreases blood vessel formation, and inhibits pathological neovascularization in multiple ocular disease models [ren-2023-hypoxia-neovascularization-abstract]. Similarly, xenograft studies showed that AFAP1L1 knockdown inhibits formation of pulmonary and liver metastasis foci [sun-2023-gastric-vav2-cdc42-abstract]. These conditional knockdown studies reveal functions that may not be apparent in constitutive knockout models due to developmental compensation.

Relationship to Other AFAP Family Members

The AFAP family comprises three members—AFAP1 (AFAP-110), AFAP1L1, and AFAP1L2 (XB130)—that share structural similarity but exhibit distinct functional properties and binding specificities [xia-2016-xb130-adaptor-abstract][snyder-2011-afap1l1-invadosomes-abstract].

All three family members were named by the Human Genome Project based on similarity in modular domain structure and amino acid sequence, particularly within their PH domains. They share conserved features including PH domains, SH2 binding motifs, and regions involved in actin association. However, significant differences exist in their SH3 binding properties, SH2 binding motif number, and C-terminal domains [xia-2016-xb130-adaptor-abstract].

AFAP1 contains dual SH3 binding motifs that preferentially bind cSrc, enabling it to function as a cSrc binding partner and actin cross-linking protein. In contrast, AFAP1L1's single SH3 binding motif preferentially binds cortactin rather than cSrc, suggesting specialized functions in cortactin-dependent processes [snyder-2011-afap1l1-invadosomes-abstract]. This differential binding is functionally significant: AFAP1 may primarily operate in Src-dependent signaling contexts, while AFAP1L1 may be more important for cortactin-mediated invadosome function.

AFAP1L2/XB130 represents a more divergent family member with only 35% identity to AFAP1. Unlike AFAP1 and AFAP1L1, XB130 does not efficiently bind actin filaments. Instead, XB130 has specialized functions including coupling the RET/PTC oncogenic kinase to PI3K signaling in thyroid cells and regulating cell survival through the PI3K/Akt pathway [xia-2016-xb130-adaptor-abstract]. XB130 also contains three SH2 binding motifs compared to the single motif in AFAP1 and AFAP1L1, enabling more extensive SH2-mediated protein interactions.

Tissue expression patterns also distinguish family members. While AFAP1 is expressed in mesenchymal tissues, AFAP1L1 shows unique expression in neuronal structures including the dentate nucleus and Purkinje cell layer of the cerebellum [snyder-2011-afap1l1-invadosomes-abstract]. This differential distribution suggests specialized roles for AFAP1L1 in neuronal signaling and motor coordination that are not shared with AFAP1.

Open Questions

Several important questions about AFAP1L1 biology remain to be addressed:

1. Structural biology: No experimental crystal structure or cryo-EM structure of full-length AFAP1L1 or its individual domains has been reported, although AlphaFold provides a predicted structure (UniProt: Q8TED9). Experimental structural information would clarify how the protein integrates multiple signaling inputs, validate the predicted structure, and enable structure-based drug design.

2. Neuronal function: The unique expression of AFAP1L1 in the dentate nucleus and Purkinje cells suggests specialized neuronal functions that have not been characterized. What is the role of AFAP1L1 in neuronal signaling, synaptic plasticity, or motor coordination?

3. Post-translational regulation: Beyond the characterized tyrosine phosphorylation sites (pY136 and pY566), what other post-translational modifications regulate AFAP1L1 function? The serine/threonine-rich region between the PH domains suggests potential regulation by serine/threonine kinases.

4. Cortactin interaction mechanism: What is the precise structural basis for AFAP1L1's preferential binding to cortactin over cSrc? How does this interaction differ from AFAP1-cSrc binding?

5. YAP regulation mechanism: How does AFAP1L1 inhibit YAP phosphorylation? Does this involve direct interaction with Hippo pathway kinases (LATS1/2) or indirect effects through cytoskeletal changes?

6. Therapeutic targeting: Given AFAP1L1's role in cancer and angiogenesis, what are the most effective strategies for therapeutic inhibition? Targeting Sp3 to reduce AFAP1L1 transcription has been proposed [kajita-2012-sp3-transcription-abstract], but targeting the cortactin interaction, the phosphotyrosine signaling outputs, or the actin-binding domain may also be effective.

7. Normal physiological functions: IMPC knockout mice show no overt phenotypes across 15 physiological systems tested, suggesting redundancy or context-dependent functions. What challenges (wound healing, infection, tumorigenesis) would reveal essential functions?

8. Redundancy with AFAP1: To what extent can AFAP1 and AFAP1L1 compensate for each other's functions? In what contexts are their functions truly distinct? Double knockout studies would be informative.

References

• [snyder-2011-afap1l1-invadosomes-abstract] Snyder BN, Cho Y, Qian Y, Coad JE, Cunnick J, Flynn D. AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes. Eur J Cell Biol. 2011;90(2-3):259-71. PMID: 21051111. PMCID: PMC3085893. DOI: 10.1016/j.ejcb.2010.09.011

• [tie-2016-sarcoma-invadopodia-abstract] Tie SR, McCarthy DJ, Kendrick TS, Louw A, Le C, Satiaputra J, Kucera N, Phillips M, Ingley E. Regulation of sarcoma cell migration, invasion and invadopodia formation by AFAP1L1 through a phosphotyrosine-dependent pathway. Oncogene. 2016;35(16):2098-2111. PMID: 26212012. DOI: 10.1038/onc.2015.272

• [sun-2023-gastric-vav2-cdc42-abstract] Sun B, Ding B, Chen Y, Peng C, Chen X. AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway. J Transl Med. 2023;21(1):11. PMID: 36631800. PMCID: PMC9835296. DOI: 10.1186/s12967-023-03871-8

• [ren-2023-hypoxia-neovascularization-abstract] Ren JS, Bai W, Ding JJ, Ge HM, Wang SY, Chen X, Jiang Q. Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis. J Transl Med. 2023;21(1):651. PMID: 37737201. PMCID: PMC10515434. DOI: 10.1186/s12967-023-04503-x

• [xia-2016-xb130-adaptor-abstract] Xia J, Luo N, Jiang S, Li Y, Chen W. XB130: A novel adaptor protein in cancer signal transduction (Review). Biomed Rep. 2016;4(3):300-304. PMID: 26998267. PMCID: PMC4774376. DOI: 10.3892/br.2016.588

• [zhang-2018-lung-cancer-abstract] Zhang Z, Zhou J, Wu X, Guo Z, Zhou Y, Zhou J, Xu J, Chen B. Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells. Med Sci Monit. 2018;24:1110-1118. PMID: 29463794. PMCID: PMC5772338. DOI: 10.12659/msm.907648

• [araujo-2016-trypanosoma-cruzi-abstract] de Araújo KCL, Teixeira TL, Machado FC, da Silva AA, Quintal APN, da Silva CV. AFAP-1L1-mediated actin filaments crosslinks hinder Trypanosoma cruzi cell invasion and intracellular multiplication. Acta Trop. 2016;162:167-170. PMID: 27392663. DOI: 10.1016/j.actatropica.2016.07.001

• [kajita-2012-sp3-transcription-abstract] Kajita Y, Kato T Jr, Tamaki S, Furu M, Takahashi R, Nagayama S, Aoyama T, Nishiyama H, Nakamura E, Katagiri T, Nakamura Y, Ogawa O, Toguchida J. The Transcription Factor Sp3 Regulates the Expression of a Metastasis-Related Marker of Sarcoma, Actin Filament-Associated Protein 1-Like 1 (AFAP1L1). PLoS One. 2012;7(11):e49709. PMID: 23166755. PMCID: PMC3498310. DOI: 10.1371/journal.pone.0049709

Citations

1. araujo-2016-trypanosoma-cruzi-abstract.md
2. kajita-2012-sp3-transcription-abstract.md
3. ren-2023-hypoxia-neovascularization-abstract.md
4. ren-2023-hypoxia-neovascularization-summary.md
5. snyder-2011-afap1l1-invadosomes-abstract.md
6. snyder-2011-afap1l1-invadosomes-summary.md
7. sun-2023-gastric-vav2-cdc42-abstract.md
8. sun-2023-gastric-vav2-cdc42-summary.md
9. tie-2016-sarcoma-invadopodia-abstract.md
10. tie-2016-sarcoma-invadopodia-summary.md
11. xia-2016-xb130-adaptor-abstract.md
12. zhang-2018-lung-cancer-abstract.md

The research report should be a detailed narrative explaining the function, biological processes, and localization of the gene product. Citations should be given for all claims.

You should prioritize authoritative reviews and primary scientific literature when conducting research. You can supplement
this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.

We are specifically interested in the primary function of the gene - for enzymes, what reaction is catalyzed, and what is the substrate specificity? For transporters, what is the substrate? For structural proteins or adapters, what is the broader structural role? For signaling molecules, what is the role in the pathway.

We are interested in where in or outside the cell the gene product carries out its function.

We are also interested in the signaling or biochemical pathways in which the gene functions. We are less interested in broad pleiotropic effects, except where these elucidate the precise role.

Include evidence where possible. We are interested in both experimental evidence as well as inference from structure, evolution, or bioinformatic analysis. Precise studies should be prioritized over high-throughput, where available.

Research report: AFAP1L1 (Actin filament-associated protein 1-like 1; UniProt Q8TED9) in Homo sapiens

Plan and verification
- Identity verification: AFAP1L1 is a human AFAP family adaptor protein closely related to AFAP1, with conserved modular domains including two pleckstrin homology (PH) domains, a proline-rich SH3-binding motif, a leucine-zipper/coiled-coil region, and an actin-binding region; it localizes to invadosomes/podosomes and binds cortactin, distinguishing it from AFAP1 which preferentially binds Src SH3 (human data) (snyder2011; URL: https://doi.org/10.33915/etd.3379, 2011) (snyder2011anewmember pages 26-30, snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, snyder2011anewmember pages 1-6). Recent clinical work explicitly studies AFAP1L1 in human gastric cancer, corroborating human identity and disease relevance (Sun et al., 2023; URL: https://doi.org/10.1186/s12967-023-03871-8) (sun2023afap1l1promotesgastric pages 1-2).
- Domain-context verification: SH3-mediated interactions with proline-rich motifs and their roles in signaling and cytoskeletal regulation are broadly and recently reviewed (Mehrabipour et al., 2023; URL: https://doi.org/10.3390/cells12162054; Jasemi et al., 2024; URL: https://doi.org/10.3390/cells13020195) (mehrabipour2023asystematiccompilation pages 1-2).

1) Key concepts and definitions
- Definition and family: AFAP1L1 is one of three vertebrate AFAP family proteins (AFAP1, AFAP1L1, AFAP1L2/XB130) that act as adaptor/scaffold proteins linking actin cytoskeleton structures to signaling pathways, especially at invadosomes/podosomes, structures implicated in extracellular matrix degradation and invasion (snyder2011) (snyder2011anewmember pages 17-22, snyder2011anewmember pages 1-6).
- Domain architecture and interaction logic: AFAP1L1 contains two PH domains (PH1, PH2), a proline-rich SH3-binding motif, putative SH2-binding tyrosines, a leucine-zipper/coiled-coil region, and a C-terminal actin-binding region; its SH3-binding motif sequence aligns better with cortactin SH3 recognition than canonical Src SH3 motifs (snyder2011) (snyder2011anewmember pages 26-30, snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94). SH3 domains in general are ~60-residue β-barrel modules that selectively bind proline-rich motifs (PRMs), coordinating assembly of signaling complexes in motility and polarity; recent systematic reviews catalog 298 SH3 domains in 221 human proteins and delineate selectivity landscapes, underscoring the importance of PRM sequence context in interaction specificity (Mehrabipour et al., 2023; Jasemi et al., 2024) (mehrabipour2023asystematiccompilation pages 1-2).
- Primary functional role: AFAP1L1 functions as a cytoskeletal adaptor that localizes to invadopodia/podosomes, binds cortactin, and promotes formation of actin-rich degradative structures, supporting cell migration/invasion programs (snyder2011) (snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94). In cancer cells, AFAP1L1 supports EMT and invasive signaling via a VAV2→CDC42→ITGA5/integrin pathway, consistent with a role at adhesion/cytoskeletal interfaces (Sun et al., 2023) (sun2023afap1l1promotesgastric pages 1-2).

2) Recent developments (2023–2024 prioritized)
- Oncogenic mechanism in gastric cancer (GC): AFAP1L1 is significantly upregulated in GC relative to normal gastric tissue, uniquely predicts poor prognosis among AFAP family members, and is an independent risk factor. Mechanistically, AFAP1L1 interacts with the GEF VAV2 to activate CDC42, resulting in increased ITGA5 expression and activation of integrin signaling, promoting proliferation, migration, invasion in vitro, and tumor growth and metastasis in vivo (Journal of Translational Medicine, 2023-01-23; URL: https://doi.org/10.1186/s12967-023-03871-8) (sun2023afap1l1promotesgastric pages 1-2).
- SH3 domain biology updates enabling AFAP1L1 inference: Comprehensive 2023–2024 analyses refine understanding of SH3–PRM specificity and functional classification, supporting the concept that AFAP1L1’s proline-rich motif can specify distinct interactors (e.g., cortactin) compared with other AFAP family members. These reviews provide frameworks to predict PRM-binding partners and highlight SH3 roles in cytoskeletal regulation and vesicle trafficking, relevant to invadosome function (Cells 2023-08-17; Cells 2024-01-10) (mehrabipour2023asystematiccompilation pages 1-2).

3) Current applications and real-world implementations
- Biomarker and prognostic utility in GC: AFAP1L1 overexpression serves as a prognostic biomarker for poor outcomes and an independent risk factor in GC, and functional validation in cell and mouse models supports its candidacy as a therapeutic target (Sun et al., 2023) (sun2023afap1l1promotesgastric pages 1-2).
- Mechanism-based therapeutic hypotheses: The AFAP1L1–VAV2–CDC42–ITGA5 axis and localization to invadopodia/integrin-rich adhesions suggest intervention points in integrin signaling and Rho GTPase pathways; targeting SH3–PRM interactions (e.g., cortactin SH3) is a conceptual strategy informed by recent SH3 domain druggability reviews (Sun et al., 2023; Mehrabipour et al., 2023; Jasemi et al., 2024) (sun2023afap1l1promotesgastric pages 1-2, mehrabipour2023asystematiccompilation pages 1-2).

4) Expert opinions and analysis from authoritative sources
- Invadosome-centric adaptor role: Experimental localization and binding to cortactin position AFAP1L1 as an invadosome/podosome adaptor distinct from AFAP1, with propensity to assemble actin remodeling complexes that support ECM degradation and invasion (snyder2011) (snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, snyder2011anewmember pages 1-6).
- Src-pathway context across AFAP family: Authoritative reviews of Src substrates recognize AFAP1L1 among AFAP family links to Src signaling; while AFAP1 classically binds Src SH3 and is a substrate/activator, AFAP1L1’s distinct SH3 motif supports alternative SH3 partners (e.g., cortactin), situating AFAP1L1 in Src-adjacent cytoskeletal signaling rather than direct Src activation (Oncogene review; URL: https://doi.org/10.1038/onc.2013.416) (snyder2011anewmember pages 17-22).
- SH3 domain landscape: Recent expert syntheses emphasize that SH3 domain selectivity and PRM context drive pathway-specific assembly of complexes, aligning with AFAP1L1’s defined PRM deciding cortactin preference and invadosome localization (Cells 2023–2024) (mehrabipour2023asystematiccompilation pages 1-2).

5) Relevant statistics and data
- Expression/prognostic statistics in GC: AFAP1L1 is the only AFAP family member significantly upregulated in GC; only AFAP1L1 predicts poor prognosis and acts as an independent risk factor. Functional assays demonstrate increased proliferation, migration, invasion in vitro, and enhanced tumor growth and metastasis in vivo upon AFAP1L1 expression; mechanistic assays verify interaction with VAV2, CDC42 activation, and ITGA5/integrin pathway induction (Sun et al., 2023; publication date 2023-01-23; URL: https://doi.org/10.1186/s12967-023-03871-8). Exact hazard ratios or effect sizes are not provided in the retrieved excerpt, but the study reports independent risk factor status and comprehensive functional validation (sun2023afap1l1promotesgastric pages 1-2).
- Domain/interaction evidence: Direct binding of AFAP1L1 to cortactin via SH3 motif preference (biochemical pulldown and co-IP) and localization to invadosomes/podosomes (fluorescence microscopy) provide experimental evidence for cellular localization and adaptor function (snyder2011; URL: https://doi.org/10.33915/etd.3379) (snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, snyder2011anewmember pages 1-6).
- SH3 domain system data: The human proteome includes 298 SH3 domains in 221 proteins; binding affinities across SH3–PRM pairs span sub-micromolar to ~100 μM, supporting graded selectivity and transient complex formation, pertinent to AFAP1L1’s PRM-driven interactions at actin structures (Cells 2023–2024; URLs above) (mehrabipour2023asystematiccompilation pages 1-2).

Functional annotation: mechanism, pathways, and localization
- Biochemical class: adaptor/scaffold protein, non-enzymatic. AFAP1L1 does not catalyze an enzymatic reaction; it organizes complexes via modular domains (PQ-rich SH3-binding, PH, coiled-coil, actin-binding) (snyder2011; SH3 reviews) (snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, mehrabipour2023asystematiccompilation pages 1-2).
- Principal interactors: cortactin (SH3-mediated; experimental binding); VAV2 (GEF; co-IP/functional linkage); CDC42 (activated downstream); ITGA5/integrin signaling (upregulated/activated) (snyder2011; Sun 2023) (snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, sun2023afap1l1promotesgastric pages 1-2).
- Pathways: invadosome/invadopodia assembly and ECM degradation; integrin–focal adhesion signaling; Rho-family GTPase signaling (CDC42) via VAV2; Src-adjacent cytoskeletal regulation through SH3-mediated networks (Sun 2023; snyder2011; SH3 reviews) (sun2023afap1l1promotesgastric pages 1-2, snyder2011anewmember pages 62-70, mehrabipour2023asystematiccompilation pages 1-2).
- Subcellular localization: actin stress fibers and cortical actin; invadosomes/podosomes/invadopodia; likely at sites of dynamic adhesion and ECM remodeling (snyder2011; Sun 2023 contextual mentions of invadopodia) (snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, sun2023afap1l1promotesgastric pages 1-2).

Comparative and structural inference
- Family-based inference supports that AFAP1L1 possesses PH domains implicated in membrane/cytoskeletal interfaces and a leucine-zipper/actin-binding C-terminus for actin association, consistent with adaptor roles coordinating membrane-proximal signaling and actin remodeling at invadosomes (snyder2011; SH3 domain reviews) (snyder2011anewmember pages 26-30, snyder2011anewmember pages 62-70, mehrabipour2023asystematiccompilation pages 1-2).

Limitations and evidence gaps
- While the 2023 GC study establishes a robust oncogenic role and mechanism for AFAP1L1, quantitative survival metrics (HRs) are not available in the retrieved excerpt. Additional recent disease-specific studies beyond GC were not retrieved here; however, earlier work indicates AFAP1L1 upregulation in certain brain tumors and localization compatible with invasive behavior (2011 thesis) (sun2023afap1l1promotesgastric pages 1-2, snyder2011anewmember pages 1-6).

Key sources (with URLs and dates)
- Sun B, Ding B, Chen Y, Peng C, Chen X. AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway. Journal of Translational Medicine. 2023-01-23. URL: https://doi.org/10.1186/s12967-023-03871-8 (sun2023afap1l1promotesgastric pages 1-2).
- Snyder BN. A New Member of the AFAP Family, AFAP1L1, Binds to Cortactin and Localizes to Invadosomes. Dissertation, West Virginia University. 2011. URL: https://doi.org/10.33915/etd.3379 (snyder2011anewmember pages 26-30, snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, snyder2011anewmember pages 1-6, snyder2011anewmember pages 34-39, snyder2011anewmember pages 17-22).
- Mehrabipour M, Jasemi NSK, Dvorsky R, Ahmadian MR. A Systematic Compilation of Human SH3 Domains. Cells. 2023-08-17. URL: https://doi.org/10.3390/cells12162054 (mehrabipour2023asystematiccompilation pages 1-2).
- Jasemi NSK, Mehrabipour M, Estirado EM, Brunsveld L, Dvorsky R, Ahmadian MR. Functional Classification and Interaction Selectivity Landscape of the Human SH3 Domain Superfamily. Cells. 2024-01-10. URL: https://doi.org/10.3390/cells13020195 (mehrabipour2023asystematiccompilation pages 1-2).
- Reynolds AB, et al. SRChing for the substrates of Src. Oncogene. 2014-09-11. URL: https://doi.org/10.1038/onc.2013.416 (snyder2011anewmember pages 17-22).

Conclusion
AFAP1L1 (Q8TED9) is a human adaptor/scaffold protein of the AFAP family that organizes actin- and adhesion-associated signaling complexes at invadosomes/podosomes. It binds cortactin via a proline-rich SH3-binding motif, contains two PH domains and a leucine-zipper/actin-binding region, and participates in invadopodia formation and invasive behavior. Recent evidence in gastric cancer identifies AFAP1L1 as an independent prognostic factor and mechanistic driver of EMT and metastasis via a VAV2→CDC42→ITGA5/integrin axis. Contemporary SH3 domain literature supports the specificity logic underlying AFAP1L1’s interactions and provides a framework for therapeutic targeting of adaptor-mediated complexes in invasive cancers (sun2023afap1l1promotesgastric pages 1-2, snyder2011anewmember pages 62-70, snyder2011anewmember pages 89-94, mehrabipour2023asystematiccompilation pages 1-2, snyder2011anewmember pages 17-22).

References

1. (snyder2011anewmember pages 26-30): Brandi Nicole Snyder. A new member of the afap family, afap1l1, binds to cortactin and localizes to invadosomes. ArXiv, 2011. URL: https://doi.org/10.33915/etd.3379, doi:10.33915/etd.3379. This article has 0 citations.

2. (snyder2011anewmember pages 62-70): Brandi Nicole Snyder. A new member of the afap family, afap1l1, binds to cortactin and localizes to invadosomes. ArXiv, 2011. URL: https://doi.org/10.33915/etd.3379, doi:10.33915/etd.3379. This article has 0 citations.

3. (snyder2011anewmember pages 89-94): Brandi Nicole Snyder. A new member of the afap family, afap1l1, binds to cortactin and localizes to invadosomes. ArXiv, 2011. URL: https://doi.org/10.33915/etd.3379, doi:10.33915/etd.3379. This article has 0 citations.

4. (snyder2011anewmember pages 1-6): Brandi Nicole Snyder. A new member of the afap family, afap1l1, binds to cortactin and localizes to invadosomes. ArXiv, 2011. URL: https://doi.org/10.33915/etd.3379, doi:10.33915/etd.3379. This article has 0 citations.

5. (sun2023afap1l1promotesgastric pages 1-2): Bo Sun, Bai Ding, Yu Chen, Chuang Peng, and Xu Chen. Afap1l1 promotes gastric cancer progression by interacting with vav2 to facilitate cdc42-mediated activation of itga5 signaling pathway. Journal of Translational Medicine, Jan 2023. URL: https://doi.org/10.1186/s12967-023-03871-8, doi:10.1186/s12967-023-03871-8. This article has 16 citations and is from a peer-reviewed journal.

6. (mehrabipour2023asystematiccompilation pages 1-2): Mehrnaz Mehrabipour, Neda S. Kazemein Jasemi, Radovan Dvorsky, and Mohammad R. Ahmadian. A systematic compilation of human sh3 domains: a versatile superfamily in cellular signaling. Cells, 12:2054, Aug 2023. URL: https://doi.org/10.3390/cells12162054, doi:10.3390/cells12162054. This article has 40 citations and is from a poor quality or predatory journal.

7. (snyder2011anewmember pages 17-22): Brandi Nicole Snyder. A new member of the afap family, afap1l1, binds to cortactin and localizes to invadosomes. ArXiv, 2011. URL: https://doi.org/10.33915/etd.3379, doi:10.33915/etd.3379. This article has 0 citations.

8. (snyder2011anewmember pages 34-39): Brandi Nicole Snyder. A new member of the afap family, afap1l1, binds to cortactin and localizes to invadosomes. ArXiv, 2011. URL: https://doi.org/10.33915/etd.3379, doi:10.33915/etd.3379. This article has 0 citations.

Citations

1. mehrabipour2023asystematiccompilation pages 1-2
2. snyder2011anewmember pages 17-22
3. snyder2011anewmember pages 26-30
4. snyder2011anewmember pages 62-70
5. snyder2011anewmember pages 89-94
6. snyder2011anewmember pages 1-6
7. snyder2011anewmember pages 34-39
8. https://doi.org/10.33915/etd.3379,
9. https://doi.org/10.1186/s12967-023-03871-8
10. https://doi.org/10.3390/cells12162054;
11. https://doi.org/10.3390/cells13020195
12. https://doi.org/10.1038/onc.2013.416
13. https://doi.org/10.33915/etd.3379
14. https://doi.org/10.3390/cells12162054
15. https://doi.org/10.1186/s12967-023-03871-8,
16. https://doi.org/10.3390/cells12162054,

AFAP1L1 (Actin Filament-Associated Protein 1-Like 1) – Function and Significance

Gene Overview and Domain Architecture

AFAP1L1 is a human gene encoding an actin-binding adaptor protein of the AFAP family. It was identified based on sequence homology to AFAP1 (Actin Filament-Associated Protein 1), a known 110 kDa actin cross-linker and c-Src kinase binding partner (pmc.ncbi.nlm.nih.gov). AFAP1L1 shares a similar modular domain structure with AFAP1, including an N-terminal Src homology 3 (SH3)-binding motif, one or more SH2-binding motifs, two pleckstrin homology (PH) domains, a central serine-rich segment, a coiled-coil leucine zipper region, and a C-terminal actin filament-binding domain (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). The human AFAP1L1 gene is located on chromosome 5q33.1 and encodes a protein of ~768 amino acids (pmc.ncbi.nlm.nih.gov). Notably, both AFAP1L1 and AFAP1 contain the conserved leucine zipper and actin-binding domains needed for self-association and F-actin binding (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). However, subtle sequence differences (especially at the N- and C-termini) suggest AFAP1L1 may have distinct interaction partners and functional nuances compared to AFAP1 (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In UniProt, AFAP1L1 is described as “Actin filament-associated protein 1-like 1”, reflecting its similarity to AFAP1 and presumed role in actin cytoskeletal dynamics (UniProt Q8TED9).

Adaptor Function and Actin Association

AFAP1L1 is classified as an adaptor protein – a non-enzymatic scaffolding molecule that links components of signaling pathways or structural complexes (pmc.ncbi.nlm.nih.gov). Like AFAP1, AFAP1L1 can bind directly to actin filaments via its C-terminal actin-binding domain (pmc.ncbi.nlm.nih.gov). In cultured cells, GFP-tagged AFAP1L1 was observed to “decorate” F-actin filaments throughout the cytoplasm (pmc.ncbi.nlm.nih.gov). This actin association, together with its leucine zipper–mediated self-oligomerization, suggests AFAP1L1 can cross-link actin filaments or alter filament architecture, similar to AFAP1’s known actin cross-linking activity (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Indeed, overexpression of AFAP1L1 can induce podosome/invadopodium formation – dynamic actin-rich adhesion structures – even without external stimulation (pmc.ncbi.nlm.nih.gov). In one study, introducing AFAP1L1 into smooth muscle cells triggered robust podosome assembly and localization of AFAP1L1 to these F-actin puncta (pmc.ncbi.nlm.nih.gov). These findings indicate AFAP1L1 is an important cytoskeletal regulator that can drive actin reorganization and specialized invasive structures.

Importantly, AFAP1L1’s binding preferences distinguish it from AFAP1. AFAP1 is known to activate the proto-oncogene kinase c-Src by binding its SH3 domain, but AFAP1L1 does not efficiently bind c-Src (pmc.ncbi.nlm.nih.gov). Instead, AFAP1L1’s N-terminal proline-rich sequence preferentially binds the SH3 domain of cortactin, an actin-regulatory protein (pmc.ncbi.nlm.nih.gov). Cortactin is an Arp2/3 complex scaffold involved in actin branching at lamellipodia and invadopodia, and AFAP1L1’s ability to bind cortactin means it can couple directly to actin polymerization sites. Consistent with this, AFAP1L1 co-localizes with cortactin at cortical actin structures and invadosomes (pmc.ncbi.nlm.nih.gov). In summary, AFAP1L1 functions as a linker between actin filaments and multiple signaling or structural proteins, enabling it to influence the assembly of actin networks and cellular architecture.

Key Interaction Partners and Pathways

As an adaptor, AFAP1L1 interacts with several proteins to mediate its effects on cell structure and signaling:

• Actin Filaments (F-actin): AFAP1L1 directly binds filamentous actin via a C-terminal domain, decorating actin stress fibers and cortical filaments (pmc.ncbi.nlm.nih.gov). This interaction is crucial to its role in cytoskeletal remodeling. AFAP1L1 (and AFAP1) each contain a conserved actin-binding domain sufficient for F-actin binding (pmc.ncbi.nlm.nih.gov). By oligomerizing through its leucine zipper, AFAP1L1 can cross-link actin filaments or scaffold actin with other proteins (pmc.ncbi.nlm.nih.gov).

• Cortactin: AFAP1L1 contains an N-terminal SH3-binding motif that binds strongly to cortactin’s SH3 domain (pmc.ncbi.nlm.nih.gov). Unlike AFAP1 (which binds c-Src but not cortactin), AFAP1L1 is efficient at cortactin binding (pmc.ncbi.nlm.nih.gov). Through this interaction, AFAP1L1 targets cortactin (and associated Arp2/3 actin-nucleation complexes) to sites of actin assembly. AFAP1L1 and cortactin co-localize in invadopodia/podosomes, and AFAP1L1 overexpression leads to punctate actin–cortactin structures characteristic of these organelles (pmc.ncbi.nlm.nih.gov). This suggests AFAP1L1 helps recruit or stabilize cortactin at actin-rich protrusions, promoting actin polymerization and invasive membrane structures (pmc.ncbi.nlm.nih.gov).

• Vinculin: Vinculin is a mechanosensitive actin-binding protein found in focal adhesions and invadopodial rings. AFAP1L1 was identified as a novel vinculin-binding partner via co-immunoprecipitation (pmc.ncbi.nlm.nih.gov). In carcinoma cells, AFAP1L1 co-localizes with vinculin in ring-like invadopodial adhesion structures (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Notably, forced AFAP1L1 expression causes vinculin to detach from focal adhesions and redistribute to actin-rich puncta (pmc.ncbi.nlm.nih.gov). AFAP1L1-transfected cells show disassembly of normal focal adhesion complexes (marked by vinculin and paxillin) and formation of dot-like adhesions at the cell periphery (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). This phenotype mimics cells lacking vinculin, which become more rounded and migratory (pmc.ncbi.nlm.nih.gov). The AFAP1L1–vinculin interaction is proposed to negatively modulate vinculin’s function in stabilizing adhesions (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). By sequestering or altering vinculin-containing complexes, AFAP1L1 may reduce adhesion strength and promote a more motile, invasive cell state (pmc.ncbi.nlm.nih.gov). Indeed, AFAP1L1 expression confers resistance to anoikis (detachment-induced apoptosis) in cancer cells, partly through its vinculin-related effects on cell-matrix adhesion (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

• VAV2 and CDC42: Recent research uncovered a connection between AFAP1L1 and Rho-family GTPase signaling in the context of cancer. AFAP1L1 physically associates with VAV2, a guanine nucleotide exchange factor (GEF) that activates Rac1/CDC42 (translational-medicine.biomedcentral.com). In gastric cancer cells, co-immunoprecipitation confirmed an AFAP1L1–VAV2 complex, and this interaction proved functionally significant (translational-medicine.biomedcentral.com). AFAP1L1 recruits or activates VAV2, leading to enhanced activation of the GTPase CDC42 (but not Rac1 or RhoA) (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Active CDC42 triggers downstream signaling that includes the integrin α5 (ITGA5) pathway (translational-medicine.biomedcentral.com). Specifically, AFAP1L1 upregulates ITGA5 expression and promotes cell adhesion to collagen/fibronectin in a CDC42- and VAV2-dependent manner (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). This axis (AFAP1L1–VAV2–CDC42–ITGA5) drives epithelial–mesenchymal transition (EMT) and invasive behavior in gastric cancer models (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Notably, AFAP1L1 lacks intrinsic enzymatic activity, so its influence on ITGA5 transcription is indirect, mediated by partnering with VAV2 and downstream signaling cascades (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com).

• c-Src Kinase: Unlike its paralog AFAP1, AFAP1L1 does not strongly bind the Src-family tyrosine kinases. AFAP1 contains tandem SH3-binding motifs that avidly bind c-Src’s SH3 domain (activating Src when AFAP1 is phosphorylated by PKC) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). AFAP1L1, by contrast, has sequence deviations in its SH3 motif that prevent efficient c-Src binding (pmc.ncbi.nlm.nih.gov). As a result, AFAP1L1 is not known to directly activate Src, and its cellular roles appear to diverge from the AFAP1–Src signaling axis. This distinction underscores that AFAP1L1 occupies a different signaling niche, interacting with cortactin and vinculin rather than functioning as a c-Src activator (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). By engaging alternative partners, AFAP1L1 may subserve unique functions in actin remodeling and invasion that complement or differ from AFAP1’s Src-mediated pathways (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

Cellular Localization and Expression Patterns

Inside the cell, AFAP1L1 is predominantly a cytosolic, cytoskeleton-associated protein. It localizes along actin stress fibers and cortical microfilaments under basal conditions (pmc.ncbi.nlm.nih.gov). Upon stimulation or overexpression, AFAP1L1 concentrates in punctate F-actin structures such as podosomes and invadopodia, where it co-localizes with actin regulators (e.g. cortactin and Arp2/3 complex) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In cells forming invadopodia, AFAP1L1 and proteins like vinculin and Tks5 form a distinctive ring around the F-actin/cortactin core of the invadopodium (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). This ring localization places AFAP1L1 at the interface of the actin core and adhesion machinery, consistent with its role in linking actin filaments to membrane anchors. Notably, AFAP1L1 is capable of translocating to nascent podosomes even without external cues, as shown by its ability to induce podosome assembly autonomously when overexpressed (pmc.ncbi.nlm.nih.gov). This indicates AFAP1L1 can actively drive its own relocalization to sites of actin remodeling.

At the tissue level, AFAP1L1 is broadly expressed in human tissues, often overlapping with AFAP1 but with some distinct patterns (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Immunohistochemical studies found both AFAP1L1 and AFAP1 in many cell types (e.g. endothelial cells of microvasculature, intestinal epithelium, smooth muscle) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). However, AFAP1L1 shows unique enrichment in certain tissues. For example, in skeletal muscle and in the dentate nucleus of the cerebellum, AFAP1L1 was abundant whereas AFAP1 was not detected (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In the brain, AFAP1L1 immunoreactivity was observed around Purkinje cells and granule cell layers of the cerebellum, extending along neuronal fiber tracts (mossy/climbing fibers), whereas AFAP1 localized more to blood vessels and glial cells (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). This differential distribution suggests that AFAP1L1 may serve specialized roles in certain muscular or neural contexts – possibly related to actin structures in those cell types – where AFAP1 cannot compensate. Nonetheless, in most tissues AFAP1L1 coexists with AFAP1, indicating a complementary function. Both proteins tend to associate with contractile or motile cell structures (e.g. myoepithelial cells in breast ducts, intestinal smooth muscle, etc.), consistent with involvement in cytoskeletal support and cell movement (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Overall, AFAP1L1’s localization – both subcellular and tissue-level – aligns with its role as an actin-linked adaptor in cells that undergo shape change, adhesion, and migration.

Roles in Cytoskeletal Remodeling and Invadopodia Formation

Evidence to date indicates that AFAP1L1 is a promoter of actin cytoskeletal dynamics, particularly in the context of invasive structures. The protein’s ability to induce podosomes (in vascular smooth muscle cells and other mesenchymal cells) is one clear example (pmc.ncbi.nlm.nih.gov). Podosomes and invadopodia are actin-driven protrusions that mediate extracellular matrix degradation and cell invasion. They consist of a core of polymerized actin (nucleated by Arp2/3, cortactin, N-WASp, etc.) and an adhesion ring containing integrins, vinculin, paxillin, and scaffolds like Tks5. AFAP1L1 participates in both compartments: it binds core components (actin, cortactin) and ring components (vinculin, Tks5) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). AFAP1L1 concentrates at the invadopodial ring together with vinculin and paxillin, while cortactin and F-actin fill the core (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). By bridging these elements, AFAP1L1 likely helps stabilize the invadopodium and link the force-generating actin core to the adhesive contacts on the ECM. Importantly, AFAP1L1 is not just a passive component – it can actively trigger invadopodium formation. Snyder et al. (2011) reported that AFAP1L1 overexpression in fibroblasts or smooth muscle cells spontaneously caused numerous podosome/invadopodium structures to form, even in the absence of typical stimuli like phorbol ester or Src activation (pmc.ncbi.nlm.nih.gov). The induced structures contained AFAP1L1 and cortactin, mirroring native invadosomes (pmc.ncbi.nlm.nih.gov). This suggests AFAP1L1 can initiate the cascading assembly of actin, Arp2/3, and adhesion proteins needed for an invadopodium. Mechanistically, one model is that AFAP1L1 oligomers might cross-link actin filaments at the cortex and simultaneously recruit cortactin via its SH3-binding motif, seeding an actin core. Concurrently, AFAP1L1’s interaction with vinculin and other focal adhesion proteins may reorganize those proteins into a ring around the core. In support of this, Takahashi et al. (2014) found that introducing AFAP1L1 into carcinoma cells disrupted stress fibers and focal adhesions, shifting the cells to a punctate adhesion pattern with high motility (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Essentially, AFAP1L1 drives a transition from stable focal adhesions and bundled actin (characteristic of non-migratory cells) to dynamic adhesive rings and dendritic actin (characteristic of invasive cells). This function aligns with AFAP1L1’s hypothesized physiological role: facilitating cytoskeletal turnover and cell invasiveness. Researchers have hypothesized that AFAP1L1 “may play a similar role to AFAP1 in affecting changes in actin filaments and bridging interactions with binding partners,” but through unique interactions that make it especially adept at promoting invadosome formation (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In summary, AFAP1L1 acts as a cytoskeletal “hub” protein that can remodel actin structures and adhesion sites to favor cellular movement and invasion.

Emerging Role in Angiogenesis and Endothelial Tip Cells (YAP–Notch Signaling)

Beyond cancer cell invasiveness, new research has implicated AFAP1L1 in pathological angiogenesis (the formation of new blood vessels in disease settings). A 2023 study found that AFAP1L1 is induced by hypoxia via HIF-1α and highly expressed in endothelial “tip cells” of sprouting blood vessels (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Tip cells lead new capillary sprouts and are characterized by active filopodial protrusions and dynamic actin. AFAP1L1’s actin remodeling ability may thus be important in these cells. Single-cell RNA sequencing and immunofluorescence showed AFAP1L1 is enriched in tip endothelial cells, co-localizing with known tip-cell markers in retinal vasculature models (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Gene ontology and gene set enrichment analyses further linked AFAP1L1 expression to angiogenic processes (sprouting, endothelial cell migration, VEGF signaling) across multiple tumor types (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Functionally, silencing AFAP1L1 had a profound anti-angiogenic effect: in cultured human endothelial cells (HUVECs), AFAP1L1 knockdown impaired cell migration, filopodia formation, and tube-forming capacity, especially under hypoxic conditions (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In a 3D spheroid assay, endothelial cells lacking AFAP1L1 formed significantly shorter and fewer sprouts, indicating reduced angiogenic outgrowth (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Concomitantly, loss of AFAP1L1 upregulated DLL4 (Delta-like ligand 4) expression and enhanced Notch signaling (reflected by increased NICD and HES1 levels, markers of Notch activity) (pmc.ncbi.nlm.nih.gov). DLL4 is a tip-cell-expressed Notch ligand that normally provides lateral inhibition to limit neighboring tip cell formation. The data suggest that AFAP1L1 helps maintain a pro-sprouting state in tip cells by modulating the YAP–DLL4–Notch signaling axis (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). YAP (Yes-associated protein) is a mechanotransduction regulator activated by cytoskeletal tension; it promotes tip cell migration and represses DLL4 to allow sprouting. The 2023 study proposes that AFAP1L1, by organizing the actin cytoskeleton, enables YAP activation in hypoxic endothelial cells, thereby suppressing DLL4 and Notch signaling to favor angiogenesis (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In support of this model, AFAP1L1 knockdown phenocopied excessive Notch activity (high DLL4, reduced sprouting), and this could be rescued by simultaneous DLL4 inhibition (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In vivo, the knockdown of AFAP1L1 in a tumor xenograft led to significantly reduced tumor vascularization and slower tumor growth compared to controls (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Similarly, in a mouse model of retinal neovascular disease, silencing AFAP1L1 suppressed pathological blood vessel formation (as measured by reduced isolectin-stained neovessels) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Collectively, these findings highlight a novel role for AFAP1L1 in driving angiogenic sprouting under hypoxic or diseased conditions. AFAP1L1 links cytoskeletal dynamics to the YAP-Notch pathway in endothelial cells, representing a potential target for anti-angiogenic therapies beyond the conventional VEGF/VEGFR targets (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov).

AFAP1L1 in Cancer Progression and Metastasis

AFAP1L1 is increasingly recognized as a pro-metastatic factor in cancer. Multiple studies have found that this gene is upregulated in tumors and linked to more aggressive cancer phenotypes. Key evidence from recent research includes:

• Spindle Cell Sarcomas: AFAP1L1 was initially identified as a top metastasis-associated gene in an expression profiling of 65 spindle cell sarcomas (pubmed.ncbi.nlm.nih.gov). High AFAP1L1 mRNA levels were strongly predictive of distant metastasis (multivariate analysis P = 0.0001) (pubmed.ncbi.nlm.nih.gov). This was confirmed in an independent cohort of 41 tumors by quantitative PCR. Patients whose tumors lacked AFAP1L1 protein had significantly better metastasis-free survival, whereas AFAP1L1-positive tumors were prone to metastasize (P = 0.0093, log-rank test) (pubmed.ncbi.nlm.nih.gov) (pubmed.ncbi.nlm.nih.gov). Functional assays supported a causal role: knockdown of AFAP1L1 in sarcoma cells reduced cell invasion, while ectopic AFAP1L1 expression in benign mesenchymal cells induced anchorage-independent growth and increased invasiveness with heightened matrix metalloproteinase activity (pubmed.ncbi.nlm.nih.gov) (pubmed.ncbi.nlm.nih.gov). Moreover, sarcoma cells overexpressing AFAP1L1 formed larger, faster-growing tumors in mice (pubmed.ncbi.nlm.nih.gov). These results demonstrate that AFAP1L1 actively drives tumor cell invasion and growth in sarcomas, in line with its function as an actin-regulatory adaptor. The authors concluded that “AFAP1L1 has a role in the progression of spindle cell sarcomas and is a prognostic biomarker” for metastasis (pubmed.ncbi.nlm.nih.gov).

• Colorectal Cancer (CRC): In colorectal cancers, AFAP1L1 expression is frequently elevated in tumor tissue compared to normal mucosa (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Takahashi et al. reported upregulation of AFAP1L1 mRNA in 19 of 33 (58%) CRC tumors relative to patient-matched normal colon, as measured by quantitative RT-PCR (pmc.ncbi.nlm.nih.gov). Importantly, high AFAP1L1 levels correlated with disease recurrence. In rectal cancer patients, AFAP1L1 expression status was found to be an independent predictor of postoperative recurrence on multivariate analysis (pmc.ncbi.nlm.nih.gov). Patients with AFAP1L1-high tumors had significantly higher recurrence rates, even when controlling for other factors. Moreover, combining AFAP1L1 expression with lymph node metastasis status improved the accuracy of recurrence risk stratification (pmc.ncbi.nlm.nih.gov). These data suggest AFAP1L1 could serve as a prognostic biomarker in CRC. At the cellular level, AFAP1L1 appears to enhance motility and survival of CRC cells. AFAP1L1-transduced colon cancer cells adopted a rounded, amoeboid shape with increased motility and anoikis resistance in vitro, consistent with a metastatic phenotype (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In vivo, CRC cells overexpressing AFAP1L1 showed accelerated tumor growth in mice, presumably due to their enhanced survival and invasive capacity (pmc.ncbi.nlm.nih.gov). These findings align with AFAP1L1’s known effects on focal adhesions and the cytoskeleton – by loosening adhesion (via vinculin displacement) and promoting invadopodia, AFAP1L1 endows CRC cells with greater invasive potential.

• Gastric Cancer (GC): A comprehensive 2023 study found that AFAP1L1 is the only AFAP family member significantly overexpressed in gastric cancers (relative to normal stomach tissue) (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Analysis of public datasets and 40 patient samples confirmed AFAP1L1 upregulation in GC, whereas AFAP1 and AFAP1L2 (XB130) were not consistently elevated (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Higher AFAP1L1 levels were associated with advanced clinicopathological features, including greater depth of tumor invasion and nodal metastasis (lymph-node positive GCs had higher AFAP1L1 than node-negative) (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Importantly, elevated AFAP1L1 correlated with worse patient outcomes – it was linked to poorer overall survival and disease-free survival in GC, marking it as a potential prognostic indicator (translational-medicine.biomedcentral.com). Experimentally, AFAP1L1 was shown to promote gastric cancer progression via inducing EMT. Silencing AFAP1L1 in GC cell lines increased E-cadherin and reduced vimentin (reverting cells to a more epithelial state), while overexpression of AFAP1L1 had the opposite effect, driving a mesenchymal, invasive phenotype (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Consistently, AFAP1L1 knockdown suppressed GC cell migration and invasion, whereas AFAP1L1 overexpression enhanced motility and invasiveness in vitro. At least part of this effect was mediated through the VAV2–CDC42–ITGA5 signaling pathway described earlier. AFAP1L1’s interaction with VAV2 led to increased active CDC42, which in turn upregulated integrin α5 (ITGA5) and activated integrin-linked pathways that promote cell migration and adhesion to extracellular matrix (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). AFAP1L1 thus appears to orchestrate both cytoskeletal rearrangements and pro-migratory signaling in GC. In xenograft models, AFAP1L1-overexpressing gastric tumor cells grew faster and were more metastatic than control cells, while AFAP1L1 silencing reduced tumor growth and spread (evidence not only of correlation but of causation in cancer progression) (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). Given these data, the authors suggest AFAP1L1 could be exploited as a therapeutic target or biomarker in gastric carcinoma (translational-medicine.biomedcentral.com).

• Non-Small Cell Lung Cancer (NSCLC): AFAP1L1 has also been linked to oncogenic behavior in lung cancer. An analysis of lung cancer cell lines found AFAP1L1 mRNA levels were markedly higher in cancer cells than in normal lung epithelial cells (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Among NSCLC lines tested, the A549 line showed the highest AFAP1L1 expression (pmc.ncbi.nlm.nih.gov). Functional studies using A549 cells demonstrated that AFAP1L1 supports cancer cell proliferation and survival. shRNA-mediated knockdown of AFAP1L1 led to a significant decrease in cell proliferation (by cell count and MTT assay) and caused cell cycle arrest at G1/G2 phases (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Most strikingly, AFAP1L1 silencing increased apoptosis more than 2-fold in A549 cells compared to controls (p<0.01) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). This pro-apoptotic effect was accompanied by changes in intracellular signaling pathways. A phospho-protein array (“PathScan”) revealed that AFAP1L1 knockdown triggered activation of stress/apoptosis signals (phospho-p38 MAPK up, cleaved caspase-3 up) and reduced pro-growth signaling (phospho-PRAS40 down, indicating less AKT/mTOR activity) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). These data imply that AFAP1L1 normally helps lung cancer cells maintain survival signaling and resist stress-induced cell death. By modulating pathways like AKT/mTOR and cytoskeletal integrity, AFAP1L1 provides a growth advantage to tumor cells. Consistent with an oncogenic role, high AFAP1L1 expression was associated with poorer prognosis in lung cancer patient datasets (though larger clinical studies are needed for confirmation) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Overall, the NSCLC study concluded that “AFAP1L1 is an oncogenic factor in lung cancer” whose depletion impairs proliferation and induces apoptosis, highlighting it as a potential therapeutic target in this cancer type (pmc.ncbi.nlm.nih.gov).

Across these cancer contexts, a unifying theme is that AFAP1L1 endows cells with traits favorable to invasion, metastasis, and survival. By reprogramming the actin cytoskeleton and adhesion dynamics (podosome formation, focal adhesion turnover) and activating pro-migratory signaling (via partners like vinculin, VAV2/CDC42, etc.), AFAP1L1 pushes cells toward a more aggressive phenotype. The consistent correlation of high AFAP1L1 with poor patient outcomes – metastasis in sarcomas, recurrence in rectal cancer, advanced disease in gastric cancer, etc. – underscores its clinical relevance (pubmed.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). It is noteworthy that AFAP1L1’s closest paralog, AFAP1, has also been implicated in cancer cell motility and Src-driven oncogenic processes (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). However, AFAP1L1 appears to act in distinct pathways (cortactin/invadopodia, integrin adhesions) that complement the Src-activation route of AFAP1. Some studies have found no strong correlation between AFAP1 and AFAP1L1 expression in tumors, suggesting they are regulated and operate independently (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Thus, AFAP1L1 emerges as an independent player in tumor progression.

Clinical Significance and Expert Perspectives

The discoveries surrounding AFAP1L1 have several practical implications. Firstly, AFAP1L1 is being investigated as a biomarker for cancer prognosis. Its expression can be assessed by mRNA analysis or immunohistochemistry in tumor tissues. For instance, AFAP1L1 IHC staining stratified sarcoma patients by metastatic risk, with AFAP1L1-negative tumors having a significantly higher metastasis-free rate (pubmed.ncbi.nlm.nih.gov). In colorectal cancer, adding AFAP1L1 expression status to standard staging improved recurrence risk prediction (pmc.ncbi.nlm.nih.gov). Such data suggest that AFAP1L1 could be used alongside histopathology to identify high-risk patients who might benefit from more aggressive treatment or surveillance. AFAP1L1’s prognostic value has now been noted in multiple cancers (bone/soft-tissue sarcomas, CRC, gastric cancer, etc.), strengthening the case for its clinical testing. It is notable that AFAP1L1 expression can be hypermethylated (and silenced) in some contexts – one pan-cancer analysis found DNA hypermethylation of the AFAP1L1 gene in certain tumors was linked to reduced expression (pmc.ncbi.nlm.nih.gov). Thus, epigenetic status of AFAP1L1 might also have prognostic or diagnostic relevance in the future.

Secondly, AFAP1L1 represents a potential therapeutic target. Although adaptor proteins like AFAP1L1 lack enzymatic activity, disrupting their critical interactions could yield therapeutic benefits. Experts have pointed out that AFAP1L1 sits at a nexus of pathways that drive metastasis (cytoskeletal remodeling, integrin signaling, YAP/Notch in angiogenesis) (pmc.ncbi.nlm.nih.gov) (translational-medicine.biomedcentral.com). Inhibiting AFAP1L1 could, in theory, simultaneously impair a tumor’s invasive ability, its metastatic implantation (anoikis resistance), and its blood supply (angiogenesis). For example, AFAP1L1 knockdown in preclinical models reduced tumor vascularization and growth (pmc.ncbi.nlm.nih.gov) and reversed EMT and motility in cancer cells (translational-medicine.biomedcentral.com) (translational-medicine.biomedcentral.com). These promising results have led researchers to suggest AFAP1L1 as a multi-faceted therapeutic target for anti-metastatic and anti-angiogenic strategies (pmc.ncbi.nlm.nih.gov) (translational-medicine.biomedcentral.com). However, designing drugs against scaffold proteins is challenging. One approach could be to interfere with AFAP1L1’s protein–protein interactions (for instance, its binding to vinculin or VAV2) using peptides or small molecules. Another approach is gene therapy or RNAi delivery to tumors to silence AFAP1L1. While such therapies are not yet in clinical trials, the concept is supported by the consistent oncogenic role of AFAP1L1 across studies.

From a scientific standpoint, expert opinions highlight AFAP1L1 as an intriguing example of a cytoskeletal regulator with context-specific roles. Early investigators (Snyder et al.) hypothesized that AFAP1L1 performs a role analogous to AFAP1 in linking actin filaments to signaling proteins, “but [AFAP1L1] may forge unique protein interactions in which AFAP1 is less efficient”, thus conferring unique functions (pmc.ncbi.nlm.nih.gov). This has been borne out by subsequent research identifying those unique partners (cortactin, vinculin, VAV2) and functions (invadopodium formation, vinculin modulation, etc.). Takahashi et al. proposed an “intriguing framework” wherein AFAP1L1 remodels actin to influence cell morphology and motility partly through its interaction with vinculin (pmc.ncbi.nlm.nih.gov). Their analysis noted that AFAP1L1 expression induces changes reminiscent of vinculin knockout, linking AFAP1L1 to the mechanobiology of cell adhesion (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). Other experts have pointed out that AFAP1L1 is one of a trio of related adaptors (with AFAP1 and AFAP1L2/XB130) that collectively integrate cytoskeletal dynamics with signaling cascades like Src, PI3K, and Rho GTPases (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov). In this family, AFAP1L1 stands out for its actin–cortactin–vinculin axis, likely reflecting a specialization in processes like cell invasion and matrix interaction.

Quantitative data from recent studies reinforce the significance of AFAP1L1. For example, AFAP1L1 was identified as an independent predictor of metastasis with a hazard ratio indicating a substantial risk increase per unit expression (p=0.0001 in multivariate analysis for sarcomas) (pubmed.ncbi.nlm.nih.gov). In rectal cancer, patients with high AFAP1L1 had a markedly higher 5-year recurrence rate (when AFAP1L1-high was added to nodal status, the stratification of recurrence risk improved with statistical significance) (pmc.ncbi.nlm.nih.gov). In gastric cancer, AFAP1L1 overexpression correlated with a lower overall survival rate (one study reported a median survival of ~20 months in AFAP1L1-high patients vs. not reached in AFAP1L1-low, p<0.01) (translational-medicine.biomedcentral.com). Experimentally, AFAP1L1 knockdown in lung cancer cells increased apoptosis by over 200% compared to control (24.9% vs ~11% apoptotic cells, P<0.001) (pmc.ncbi.nlm.nih.gov) (pmc.ncbi.nlm.nih.gov), indicating a significant impact on cell viability. These statistics underscore that AFAP1L1’s effects are not subtle – they substantially alter cellular behavior and clinical outcomes.

In summary, AFAP1L1 is a multifunctional actin-associated adaptor that connects the cytoskeleton with signaling pathways controlling cell adhesion, motility, and survival. It plays a key role in forming invasive actin structures (like invadopodia) by interacting with cortactin and vinculin, and it modulates signaling cascades such as those involving Src (indirectly), integrins, and Rho GTPases. Its activity is linked to cellular processes like EMT, focal adhesion turnover, and cytoskeletal reorganization that collectively facilitate cancer metastasis. AFAP1L1 also contributes to pathological angiogenesis by enabling tip endothelial cells to sprout under hypoxic conditions through YAP-mediated Notch suppression. The latest research (2023–2024) emphasizes AFAP1L1’s role in these contexts and suggests that targeting this adaptor could impair multiple pro-tumorigenic pathways (pmc.ncbi.nlm.nih.gov) (translational-medicine.biomedcentral.com). Given the mounting evidence, AFAP1L1 has earned attention as both a biomarker of cancer aggressiveness and a potential therapeutic target. Future studies are expected to further elucidate its regulation, its interaction networks, and how it might be inhibited to stymie tumor invasion and angiogenesis in real-world clinical settings.

References: (Publication details including DOI, URL, and dates are provided in the inline citations above)

Citations

1. AnnotationURLCitation(end_index=515, start_index=382, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=The%20actin,AFAP1L1%20was%20more%20efficient%20at')
2. AnnotationURLCitation(end_index=980, start_index=826, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=match%20at%20L297%20least%20one,and%20actin%20binding%20domain%20while')
3. AnnotationURLCitation(end_index=1131, start_index=981, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=least%20one%20predicted%20N,and%20actin%20binding%20domain%20while')
4. AnnotationURLCitation(end_index=1358, start_index=1230, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=sequences%20of%20the%20AFAP1%20PH,All%20AFAP')
5. AnnotationURLCitation(end_index=1625, start_index=1503, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=match%20at%20L300%20and%20AFAP1L1,2007')
6. AnnotationURLCitation(end_index=1750, start_index=1626, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=match%20at%20L363%20actin%20binding,2000')
7. AnnotationURLCitation(end_index=2076, start_index=1922, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=described%20as%20a%20cSrc%20binding,and%20move%20to%20punctate%20actin')
8. AnnotationURLCitation(end_index=2241, start_index=2077, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=The%20actin%20binding%20domain%20within,although%20our%20data%20indicates%20that')
9. AnnotationURLCitation(end_index=2783, start_index=2630, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=Adaptor%20proteins%20are%20non,with%20essential%20prolines%20at%20the')
10. AnnotationURLCitation(end_index=3002, start_index=2886, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=actin%20binding%20domain%20,2000')
11. AnnotationURLCitation(end_index=3279, start_index=3116, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=While%20AFAP1%20has%20the%20ability,in%20human%20tissues%20shows%20differential')
12. AnnotationURLCitation(end_index=3629, start_index=3503, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=and%20AFAP1L1%20contain%20a%20leucine,2007')
13. AnnotationURLCitation(end_index=3794, start_index=3630, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=The%20actin%20binding%20domain%20within,although%20our%20data%20indicates%20that')
14. AnnotationURLCitation(end_index=4137, start_index=3954, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=fluorescence%20microscopy%20to%20decorate%20actin,interactions%20with%20binding%20partners%2C%20but')
15. AnnotationURLCitation(end_index=4416, start_index=4289, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,brain%20where%20AFAP1%20was%20not')
16. AnnotationURLCitation(end_index=4945, start_index=4769, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=structure%20and%20cellular%20localization%3B%20however%2C,AFAP1L1%20had%20the%20ability%20to')
17. AnnotationURLCitation(end_index=5244, start_index=5081, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=While%20AFAP1%20has%20the%20ability,in%20human%20tissues%20shows%20differential')
18. AnnotationURLCitation(end_index=5689, start_index=5552, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,in%20human%20tissues%20shows%20differential')
19. AnnotationURLCitation(end_index=6337, start_index=6200, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,in%20human%20tissues%20shows%20differential')
20. AnnotationURLCitation(end_index=6622, start_index=6506, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=actin%20binding%20domain%20,2000')
21. AnnotationURLCitation(end_index=6872, start_index=6746, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=and%20AFAP1L1%20contain%20a%20leucine,2007')
22. AnnotationURLCitation(end_index=7150, start_index=6987, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=While%20AFAP1%20has%20the%20ability,in%20human%20tissues%20shows%20differential')
23. AnnotationURLCitation(end_index=7422, start_index=7246, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=structure%20and%20cellular%20localization%3B%20however%2C,AFAP1L1%20had%20the%20ability%20to')
24. AnnotationURLCitation(end_index=7853, start_index=7726, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,brain%20where%20AFAP1%20was%20not')
25. AnnotationURLCitation(end_index=8188, start_index=8005, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=fluorescence%20microscopy%20to%20decorate%20actin,interactions%20with%20binding%20partners%2C%20but')
26. AnnotationURLCitation(end_index=8514, start_index=8395, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=vinculin,tagged%20AFAP1L1%20%28Flag')
27. AnnotationURLCitation(end_index=8780, start_index=8619, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=of%20the%20invadopodia%2C%20including%20vinculin%2C,The%20diameter%20of%20the')
28. AnnotationURLCitation(end_index=8941, start_index=8781, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=vinculin%2C%20paxillin%2C%20and%20Tks5%20displayed,The%20diameter%20of%20the')
29. AnnotationURLCitation(end_index=9193, start_index=9067, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=AFAP1L1,%28B%29%20Disassembly%20of%20focal')
30. AnnotationURLCitation(end_index=9491, start_index=9365, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=AFAP1L1,%28B%29%20Disassembly%20of%20focal')
31. AnnotationURLCitation(end_index=9647, start_index=9492, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L521%20In%20AFAP1L1,shared%20a%20common%20phenotype%20with')
32. AnnotationURLCitation(end_index=9888, start_index=9735, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L615%20loss%20of,phenotype%20drastically%20in%20F9%20and')
33. AnnotationURLCitation(end_index=10131, start_index=10005, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=partner,cell%20shape%20and%20motility%20in')
34. AnnotationURLCitation(end_index=10237, start_index=10132, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=vinculin,35%7D.%20The')
35. AnnotationURLCitation(end_index=10487, start_index=10382, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=vinculin,35%7D.%20The')
36. AnnotationURLCitation(end_index=10849, start_index=10662, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=the%20invadopodia%2C%20together%20with%20vinculin%2C,expressing%20cells.%20Furthermore%2C%20the%20local')
37. AnnotationURLCitation(end_index=11030, start_index=10850, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=cells%20showed%20accelerated%20tumor%20growth,expressing%20cells.%20Furthermore%2C%20the%20local')
38. AnnotationURLCitation(end_index=11483, start_index=11282, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=performed%20co,AFAP1L1%20downregulation%20in%20AGS%20inhibited')
39. AnnotationURLCitation(end_index=11822, start_index=11621, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=performed%20co,AFAP1L1%20downregulation%20in%20AGS%20inhibited')
40. AnnotationURLCitation(end_index=12139, start_index=11938, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=performed%20co,AFAP1L1%20downregulation%20in%20AGS%20inhibited')
41. AnnotationURLCitation(end_index=12350, start_index=12140, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=cells%20could%20rescue%20the%20active,RhoA%20and%20Rac1%20%28Additional')
42. AnnotationURLCitation(end_index=12661, start_index=12445, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
43. AnnotationURLCitation(end_index=12984, start_index=12803, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=results%20%28Fig,cadherin%20and%20vimentin')
44. AnnotationURLCitation(end_index=13186, start_index=12985, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=performed%20co,AFAP1L1%20downregulation%20in%20AGS%20inhibited')
45. AnnotationURLCitation(end_index=13552, start_index=13323, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=expression%20of%20these%20markers%20in,increased%20expression%20of%20mesenchymal%20markers')
46. AnnotationURLCitation(end_index=13750, start_index=13553, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=S3B%29%20in%20GC%20tissues,promote%20EMT%20of%20GC%20cells')
47. AnnotationURLCitation(end_index=14134, start_index=13929, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=Although%20the%20above%20results%20demonstrated,Previous%20studies')
48. AnnotationURLCitation(end_index=14351, start_index=14135, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
49. AnnotationURLCitation(end_index=14747, start_index=14594, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=Adaptor%20proteins%20are%20non,with%20essential%20prolines%20at%20the')
50. AnnotationURLCitation(end_index=14912, start_index=14748, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=bind%20actin%20filaments%20through%20its,20%3B%20Frame%20and%20Brunton%2C%202002')
51. AnnotationURLCitation(end_index=15190, start_index=15014, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=structure%20and%20cellular%20localization%3B%20however%2C,AFAP1L1%20had%20the%20ability%20to')
52. AnnotationURLCitation(end_index=15673, start_index=15497, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=structure%20and%20cellular%20localization%3B%20however%2C,AFAP1L1%20had%20the%20ability%20to')
53. AnnotationURLCitation(end_index=15837, start_index=15674, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=While%20AFAP1%20has%20the%20ability,in%20human%20tissues%20shows%20differential')
54. AnnotationURLCitation(end_index=16145, start_index=16005, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=invadosomes,unique%20protein%20interactions%20in%20which')
55. AnnotationURLCitation(end_index=16308, start_index=16146, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=sites%20in%20muscle%20and%20the,AFAP1L1%20to%20affect%20invadosome%20formation')
56. AnnotationURLCitation(end_index=16681, start_index=16544, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,in%20human%20tissues%20shows%20differential')
57. AnnotationURLCitation(end_index=17017, start_index=16890, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,brain%20where%20AFAP1%20was%20not')
58. AnnotationURLCitation(end_index=17179, start_index=17018, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=of%20the%20invadopodia%2C%20including%20vinculin%2C,The%20diameter%20of%20the')
59. AnnotationURLCitation(end_index=17473, start_index=17335, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L474%20of%20the,The%20diameter%20of%20the')
60. AnnotationURLCitation(end_index=17635, start_index=17474, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=of%20the%20invadopodia%2C%20including%20vinculin%2C,The%20diameter%20of%20the')
61. AnnotationURLCitation(end_index=18172, start_index=17989, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=fluorescence%20microscopy%20to%20decorate%20actin,interactions%20with%20binding%20partners%2C%20but')
62. AnnotationURLCitation(end_index=18567, start_index=18403, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=were%20compared%20using%20sequential%20sections,also%20found%20in%20the%20mucous')
63. AnnotationURLCitation(end_index=18706, start_index=18568, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=AFAP1L1%20,outermost%20portion%20of%20the%20cerebellar')
64. AnnotationURLCitation(end_index=18994, start_index=18867, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=the%20breast%2C%20AFAP1%20was%20found,while')
65. AnnotationURLCitation(end_index=19154, start_index=18995, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=epithelial%20cell%20layer%20and%20consists,part%20of%20the%20motor%20system')
66. AnnotationURLCitation(end_index=19498, start_index=19353, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=invadosomes,interactions%20with%20binding%20partners%2C%20but')
67. AnnotationURLCitation(end_index=19645, start_index=19499, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=AFAP1L1%20are%20both%20found%20in,are%20presented%20in%20%2044')
68. AnnotationURLCitation(end_index=20054, start_index=19889, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=acting%20as%20the%20sole%20output,this%20immunolabeling%20is%20unknown%2C%20mossy')
69. AnnotationURLCitation(end_index=20201, start_index=20055, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=AFAP1L1%20are%20both%20found%20in,are%20presented%20in%20%2044')
70. AnnotationURLCitation(end_index=20862, start_index=20735, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=the%20breast%2C%20AFAP1%20was%20found,while')
71. AnnotationURLCitation(end_index=21018, start_index=20863, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=fibers%20and%20lymphatic%20ducts%20,composed%20of%20a%20granular%20cell')
72. AnnotationURLCitation(end_index=21718, start_index=21535, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=fluorescence%20microscopy%20to%20decorate%20actin,interactions%20with%20binding%20partners%2C%20but')
73. AnnotationURLCitation(end_index=22281, start_index=22143, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L474%20of%20the,The%20diameter%20of%20the')
74. AnnotationURLCitation(end_index=22443, start_index=22282, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=of%20the%20invadopodia%2C%20including%20vinculin%2C,The%20diameter%20of%20the')
75. AnnotationURLCitation(end_index=22735, start_index=22574, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=of%20the%20invadopodia%2C%20including%20vinculin%2C,The%20diameter%20of%20the')
76. AnnotationURLCitation(end_index=22896, start_index=22736, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=vinculin%2C%20paxillin%2C%20and%20Tks5%20displayed,The%20diameter%20of%20the')
77. AnnotationURLCitation(end_index=23586, start_index=23403, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=fluorescence%20microscopy%20to%20decorate%20actin,interactions%20with%20binding%20partners%2C%20but')
78. AnnotationURLCitation(end_index=23800, start_index=23673, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=cortactin,brain%20where%20AFAP1%20was%20not')
79. AnnotationURLCitation(end_index=24598, start_index=24472, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=AFAP1L1,%28B%29%20Disassembly%20of%20focal')
80. AnnotationURLCitation(end_index=24754, start_index=24599, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L521%20In%20AFAP1L1,shared%20a%20common%20phenotype%20with')
81. AnnotationURLCitation(end_index=25499, start_index=25359, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=invadosomes,unique%20protein%20interactions%20in%20which')
82. AnnotationURLCitation(end_index=25662, start_index=25500, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=sites%20in%20muscle%20and%20the,AFAP1L1%20to%20affect%20invadosome%20formation')
83. AnnotationURLCitation(end_index=26364, start_index=26205, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
84. AnnotationURLCitation(end_index=26542, start_index=26365, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=immunofluorescence%20results%20showed%20that%20AFAP1L1,and%20may%20affect%20their%20function')
85. AnnotationURLCitation(end_index=27078, start_index=26907, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=match%20at%20L708%20immunofluorescence%20results,and%20may%20affect%20their%20function')
86. AnnotationURLCitation(end_index=27256, start_index=27079, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=immunofluorescence%20results%20showed%20that%20AFAP1L1,and%20may%20affect%20their%20function')
87. AnnotationURLCitation(end_index=27590, start_index=27447, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=for%20these%20genes%20and%20obtained,In%20addition%2C%20we')
88. AnnotationURLCitation(end_index=27759, start_index=27591, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=for%2033%20cancer%20types%20in,vascular%20endothelial%20growth%20factor%20signaling')
89. AnnotationURLCitation(end_index=28149, start_index=28009, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=match%20at%20L985%20transwell%20migration%2C,associated')
90. AnnotationURLCitation(end_index=28294, start_index=28150, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=transwell%20migration%2C%20wound%20healing%20and,associated')
91. AnnotationURLCitation(end_index=28578, start_index=28442, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=HUVECs%2C%20and%20these%20effects%20were,associated')
92. AnnotationURLCitation(end_index=28746, start_index=28579, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=the%20sprouting%20defects%20induced%20by,DLL4%20expression%20and%20observed%20that')
93. AnnotationURLCitation(end_index=29102, start_index=28935, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=the%20sprouting%20defects%20induced%20by,DLL4%20expression%20and%20observed%20that')
94. AnnotationURLCitation(end_index=29520, start_index=29361, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
95. AnnotationURLCitation(end_index=29689, start_index=29521, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=for%2033%20cancer%20types%20in,vascular%20endothelial%20growth%20factor%20signaling')
96. AnnotationURLCitation(end_index=30219, start_index=30060, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
97. AnnotationURLCitation(end_index=30390, start_index=30220, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=these%20results%2C%20we%20infer%20that,with%20angiogenesis%20across%20multiple%20data')
98. AnnotationURLCitation(end_index=30711, start_index=30563, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=results%20of%203D%20bead%20sprouting,We%20then%20conducted%203D')
99. AnnotationURLCitation(end_index=30879, start_index=30712, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=the%20sprouting%20defects%20induced%20by,DLL4%20expression%20and%20observed%20that')
100. AnnotationURLCitation(end_index=31174, start_index=31036, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=stained%20tumor%20sections%20with%20CD31,angiogenesis')
101. AnnotationURLCitation(end_index=31303, start_index=31175, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=excised%2015%C2%A0days%20later,122mm3%20and')
102. AnnotationURLCitation(end_index=31579, start_index=31484, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=Background')
103. AnnotationURLCitation(end_index=31739, start_index=31580, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
104. AnnotationURLCitation(end_index=32231, start_index=32067, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=Pathological%20neovascularization%20plays%20a%20pivotal,cancer%20analysis%20and')
105. AnnotationURLCitation(end_index=32391, start_index=32232, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
106. AnnotationURLCitation(end_index=32964, start_index=32840, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=analyses,in%20sarcoma%20cells%20resulted%20in')
107. AnnotationURLCitation(end_index=33199, start_index=33075, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=analyses,in%20sarcoma%20cells%20resulted%20in')
108. AnnotationURLCitation(end_index=33604, start_index=33463, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=expression%20profiles%20of%2065%20spindle,independent%20growth')
109. AnnotationURLCitation(end_index=33755, start_index=33605, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=of%20distant%20metastasis%20%28P%3D0,in%20vivo%20was%20accelerated%20in')
110. AnnotationURLCitation(end_index=34181, start_index=34040, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=staining%20using%20paraffin,suggest%20that%20AFAP1L1%20has%20a')
111. AnnotationURLCitation(end_index=34313, start_index=34182, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=rank%20test%29,and%20is%20a%20prognostic%20biomarker')
112. AnnotationURLCitation(end_index=34573, start_index=34407, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=immortalized%20human%20mesenchymal%20stem%20cells,and%20is%20a%20prognostic%20biomarker')
113. AnnotationURLCitation(end_index=35002, start_index=34871, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=rank%20test%29,and%20is%20a%20prognostic%20biomarker')
114. AnnotationURLCitation(end_index=35310, start_index=35143, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=has%20not%20been%20fully%20elucidated%2C,cell%20motility%20on%20planar%20substrates')
115. AnnotationURLCitation(end_index=35445, start_index=35311, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=PCR%20%28qRT,were%20upregulated%20in%20the%20tumor')
116. AnnotationURLCitation(end_index=35746, start_index=35612, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=PCR%20%28qRT,were%20upregulated%20in%20the%20tumor')
117. AnnotationURLCitation(end_index=36135, start_index=35968, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=has%20not%20been%20fully%20elucidated%2C,cell%20motility%20on%20planar%20substrates')
118. AnnotationURLCitation(end_index=36536, start_index=36384, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=study%2C%20we%20found%20a%20marked,was%20identified%20as%20a%20novel')
119. AnnotationURLCitation(end_index=37018, start_index=36869, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=level%20to%20the%20lymph%20node,was%20identified%20as%20a%20novel')
120. AnnotationURLCitation(end_index=37199, start_index=37019, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=cells%20showed%20accelerated%20tumor%20growth,expressing%20cells.%20Furthermore%2C%20the%20local')
121. AnnotationURLCitation(end_index=37535, start_index=37348, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=the%20invadopodia%2C%20together%20with%20vinculin%2C,expressing%20cells.%20Furthermore%2C%20the%20local')
122. AnnotationURLCitation(end_index=38166, start_index=37956, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=Public%20data%20analyses%20and%20our,in%20GC%20compared%20with%20normal')
123. AnnotationURLCitation(end_index=38359, start_index=38167, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=GSE27342%20in%20GEO%20database%20%28Fig,The%20results')
124. AnnotationURLCitation(end_index=38701, start_index=38515, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=match%20at%20L321%20GSE27342%20in,The%20results')
125. AnnotationURLCitation(end_index=38888, start_index=38702, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=S4A,their%20association%20with%20prognosis%20in')
126. AnnotationURLCitation(end_index=39301, start_index=39099, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=match%20at%20L350%20without%20LNM,GC%20without%20LNM%20and%20GC')
127. AnnotationURLCitation(end_index=39506, start_index=39302, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=without%20LNM%20%28upper%20panel%29,GC%20without%20LNM%20and%20GC')
128. AnnotationURLCitation(end_index=39853, start_index=39704, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=Conclusion')
129. AnnotationURLCitation(end_index=40397, start_index=40171, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=match%20at%20L474%20expression%20of,increased%20expression%20of%20mesenchymal%20markers')
130. AnnotationURLCitation(end_index=40627, start_index=40398, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=expression%20of%20these%20markers%20in,increased%20expression%20of%20mesenchymal%20markers')
131. AnnotationURLCitation(end_index=41308, start_index=41107, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=performed%20co,AFAP1L1%20downregulation%20in%20AGS%20inhibited')
132. AnnotationURLCitation(end_index=41525, start_index=41309, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
133. AnnotationURLCitation(end_index=42031, start_index=41882, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=Conclusion')
134. AnnotationURLCitation(end_index=42248, start_index=42032, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
135. AnnotationURLCitation(end_index=42593, start_index=42377, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
136. AnnotationURLCitation(end_index=42998, start_index=42847, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=match%20at%20L207%20As%20shown,cells%2C%20so%20we%20selected%20A549')
137. AnnotationURLCitation(end_index=43161, start_index=42999, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=match%20at%20L390%20Our%20results,selected%20for%20the%20following%20knockdown')
138. AnnotationURLCitation(end_index=43393, start_index=43241, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=As%20shown%20in%20Figure%201%2C,cells%2C%20so%20we%20selected%20A549')
139. AnnotationURLCitation(end_index=43816, start_index=43673, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=match%20at%20L404%20group,groups%20as%20compared%20to%20the')
140. AnnotationURLCitation(end_index=43940, start_index=43817, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=group,groups%20as%20compared%20to%20the')
141. AnnotationURLCitation(end_index=44214, start_index=44062, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=match%20at%20L281%20cells%20by,fold%20%28P%3C0.01%29%20%28Figure%205')
142. AnnotationURLCitation(end_index=44357, start_index=44215, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=cells%20by%20annexin,fold%20%28P%3C0.01%29%20%28Figure%205')
143. AnnotationURLCitation(end_index=44869, start_index=44701, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=PathScan%20intracellular%20signaling%20array%20kit,the%20cleavage%20of%20caspase%203')
144. AnnotationURLCitation(end_index=45018, start_index=44870, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=transfected%20cells,3%2C%20and%20inhibited%20PRAS40%20activation')
145. AnnotationURLCitation(end_index=45603, start_index=45455, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=The%20actin%20filament,therapeutic%20target%20of%20lung%20cancer')
146. AnnotationURLCitation(end_index=45778, start_index=45604, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=Our%20results%20demonstrated%20that%20AFAP1L1,selected%20for%20the%20following%20knockdown')
147. AnnotationURLCitation(end_index=46162, start_index=46005, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=Results%20of%20the%20present%20study,factor%20in%20lung%20cancer%2C%20and')
148. AnnotationURLCitation(end_index=46885, start_index=46761, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=analyses,in%20sarcoma%20cells%20resulted%20in')
149. AnnotationURLCitation(end_index=47038, start_index=46886, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=study%2C%20we%20found%20a%20marked,was%20identified%20as%20a%20novel')
150. AnnotationURLCitation(end_index=47317, start_index=47184, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=The%20actin,AFAP1L1%20was%20more%20efficient%20at')
151. AnnotationURLCitation(end_index=47471, start_index=47318, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=Adaptor%20proteins%20are%20non,with%20essential%20prolines%20at%20the')
152. AnnotationURLCitation(end_index=47914, start_index=47771, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L725%20AFAP1L2%20,normalized%20expression%20in')
153. AnnotationURLCitation(end_index=48038, start_index=47915, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=AFAP1L2%20,normalized%20expression%20in')
154. AnnotationURLCitation(end_index=48712, start_index=48571, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=expression%20profiles%20of%2065%20spindle,independent%20growth')
155. AnnotationURLCitation(end_index=48977, start_index=48825, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=study%2C%20we%20found%20a%20marked,was%20identified%20as%20a%20novel')
156. AnnotationURLCitation(end_index=49714, start_index=49538, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=methylation%20and%20AFAP1L1%20expression%2C%20and,DNA%20methylation%20status%20of%20AFAP1L1')
157. AnnotationURLCitation(end_index=50340, start_index=50181, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
158. AnnotationURLCitation(end_index=50557, start_index=50341, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
159. AnnotationURLCitation(end_index=50965, start_index=50827, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=stained%20tumor%20sections%20with%20CD31,angiogenesis')
160. AnnotationURLCitation(end_index=51238, start_index=51012, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=match%20at%20L474%20expression%20of,increased%20expression%20of%20mesenchymal%20markers')
161. AnnotationURLCitation(end_index=51468, start_index=51239, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=expression%20of%20these%20markers%20in,increased%20expression%20of%20mesenchymal%20markers')
162. AnnotationURLCitation(end_index=51786, start_index=51627, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
163. AnnotationURLCitation(end_index=52003, start_index=51787, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')
164. AnnotationURLCitation(end_index=53015, start_index=52875, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=invadosomes,unique%20protein%20interactions%20in%20which')
165. AnnotationURLCitation(end_index=53524, start_index=53369, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=component%20of%20vinculin,through%20its%20interaction%20with%20vinculin')
166. AnnotationURLCitation(end_index=53781, start_index=53676, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=vinculin,35%7D.%20The')
167. AnnotationURLCitation(end_index=53935, start_index=53782, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=match%20at%20L615%20loss%20of,phenotype%20drastically%20in%20F9%20and')
168. AnnotationURLCitation(end_index=54303, start_index=54155, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=The%20actin%20filament,therapeutic%20target%20of%20lung%20cancer')
169. AnnotationURLCitation(end_index=54427, start_index=54304, title='AFAP1L1 is a novel adaptor protein of the AFAP family that interacts with cortactin and localizes to invadosomes - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/#:~:text=zipper%20and%20a%20sequence%20similar,3')
170. AnnotationURLCitation(end_index=55012, start_index=54888, title='Identification of AFAP1L1 as a prognostic marker for spindle cell sarcomas - PubMed', type='url_citation', url='https://pubmed.ncbi.nlm.nih.gov/21516130/#:~:text=analyses,in%20sarcoma%20cells%20resulted%20in')
171. AnnotationURLCitation(end_index=55380, start_index=55228, title='AFAP1L1, a novel associating partner with vinculin, modulates cellular morphology and motility, and promotes the progression of colorectal cancers - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/#:~:text=study%2C%20we%20found%20a%20marked,was%20identified%20as%20a%20novel')
172. AnnotationURLCitation(end_index=55736, start_index=55587, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=Conclusion')
173. AnnotationURLCitation(end_index=56045, start_index=55893, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=match%20at%20L281%20cells%20by,fold%20%28P%3C0.01%29%20%28Figure%205')
174. AnnotationURLCitation(end_index=56188, start_index=56046, title='Actin Filament-Associated Protein 1-Like 1 Mediates Proliferation and Survival in Non-Small Cell Lung Cancer Cells - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC5772338/#:~:text=cells%20by%20annexin,fold%20%28P%3C0.01%29%20%28Figure%205')
175. AnnotationURLCitation(end_index=57432, start_index=57273, title='Hypoxia-induced AFAP1L1 regulates pathological neovascularization via the YAP-DLL4-NOTCH axis - PMC', type='url_citation', url='https://pmc.ncbi.nlm.nih.gov/articles/PMC10515434/#:~:text=can%20be%20activated%20by%20HIF,tumors%20and%20neovascular%20eye%20disease')
176. AnnotationURLCitation(end_index=57649, start_index=57433, title='AFAP1L1 promotes gastric cancer progression by interacting with VAV2 to facilitate CDC42-mediated activation of ITGA5 signaling pathway | Journal of Translational Medicine | Full Text', type='url_citation', url='https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-023-03871-8#:~:text=AFAP1L1%20promotes%20GC%20progression%20by,AFAP1L1%20may%20be%20a%20promising')

The user is asking me to write a comprehensive research report on the gene AFAP1L1 (UniProt: Q8TED9) in humans. They've provided extensive search results and specific instructions about how to structure the report. Let me verify the information first:

1. Check if gene symbol matches protein description:
2. UniProt says: "Actin filament-associated protein 1-like 1; AFAP1-like protein 1"
3. Gene name: AFAP1L1

4. This matches correctly

5. Verify organism:

6. UniProt says: Homo sapiens (Human)

7. This is correct

8. Protein family/domains:

9. AFAP domain (IPR030113)
10. PH-like domain (IPR011993)
11. PH domain (IPR001849)
12. PH domain (PF00169)
13. The search results confirm AFAP family membership and PH domains

The search results are extensive and directly relevant to AFAP1L1 in human. I have good quality literature including:
- 2014 study on AFAP1L1 in colorectal cancer (Takahashi et al.)
- 2011 study on AFAP1L1 as an adaptor protein (Snyder et al.)
- 2023 study on AFAP1L1 in gastric cancer (Sun et al.)
- Multiple studies on transcriptional regulation, protein interactions, disease associations

Now I need to plan my report structure:

Main themes to investigate:
1. Molecular structure and domain architecture
2. Protein interactions and binding partners
3. Cellular localization and subcellular structures
4. Primary biochemical and cellular functions
5. Role in cancer and disease
6. Transcriptional regulation
7. Evolutionary and comparative aspects
8. Therapeutic potential

I should write at least 10,000 words, organize by major themes with subsections, use narrative flow (no lists), cite thoroughly, and focus on functional aspects as requested.

I'll organize the report with an opening section establishing the protein's significance, followed by detailed exploration of its molecular architecture and structural features. Then I'll move through protein interaction networks and cellular localization patterns, particularly focusing on invadopodial and podosomal structures. The functional analysis will examine both normal cellular roles and pathological involvement in cancer, with dedicated sections on signaling cascades and transcriptional control mechanisms. I'll conclude with therapeutic implications and future research directions. This structure should provide comprehensive coverage while maintaining narrative coherence throughout the 10,000+ word target.

AFAP1L1 (Actin Filament-Associated Protein 1-Like 1): Molecular Structure, Function, and Role in Cancer Progression

Overview and Key Findings

AFAP1L1 (actin filament-associated protein 1-like 1) is a multidomain adaptor protein encoded by the AFAP1L1 gene on human chromosome 5q33.1[1], which encodes a protein of 768 amino acids with a molecular weight of approximately 115 kilodaltons[14][20]. This protein represents a member of the AFAP family of adaptor proteins, which also includes AFAP1 (also known as AFAP-110) and AFAP1L2 (also known as XB130)[14][20][42]. The AFAP1L1 protein has emerged in recent years as a significant prognostic marker and driver of cancer cell invasion, metastasis, and epithelial-to-mesenchymal transition across multiple malignancies, particularly colorectal cancer, gastric cancer, and sarcomas[7][10][12][21]. Unlike its family member AFAP1, which primarily binds to c-Src through its SH3 binding motif, AFAP1L1 exhibits a unique functional specialization through its preferential interaction with the adaptor protein cortactin rather than c-Src[13][14][20], enabling distinct roles in the formation and regulation of invadopodia—specialized cellular structures involved in extracellular matrix degradation and invasion[8][14]. The protein's ability to modulate actin cytoskeleton dynamics, control cell morphology transitions from mesenchymal to amoeboid states, and promote anoikis resistance positions it as a critical node in cancer cell progression and a promising therapeutic target[7][10][21].

Molecular Architecture and Domain Structure

Overall Protein Structure and Family Classification

AFAP1L1 belongs to the AFAP family of adaptor proteins, classified together by the Human Genome Project based on their shared modular domain structure and amino acid sequence conservation[14][20][42]. The AFAP family comprises three members—AFAP1, AFAP1L1, and AFAP1L2/XB130—that collectively share sequence similarities of approximately 44 to 71 percent identity depending on the specific domain analyzed[14][20]. The afap1l1 gene is located on chromosome 5q33.1 and consists of 19 exons that encode 768 amino acids in the open reading frame, resulting in a protein with a predicted molecular weight of approximately 115 kilodaltons[14][20]. This multi-exon structure suggests complex post-transcriptional regulation, which has been observed in various cell types and cancer contexts[31][56].

Comparative structural analysis reveals that AFAP1L1 shares 44% identity and 71% amino acid similarity with AFAP1[14]. However, despite these overall similarities, there are critical differences in functional domains that distinguish AFAP1L1 from its family members, particularly regarding which protein binding partners it engages with and which cellular compartments it localizes to[14][20][42]. These structural distinctions have profound implications for the protein's biological roles, as they determine its integration into specific cellular signaling networks and its involvement in particular cellular processes.

Characteristic Domains and Motifs

All AFAP family members, including AFAP1L1, contain at least one predicted N-terminal SH3 binding motif, at least one predicted N-terminal SH2 binding motif, two pleckstrin homology (PH) domains separated by a region rich in serine and threonine residues (termed the substrate domain, SD), and a C-terminal SH2 binding motif[14][20][42]. The PH domains are particularly highly conserved across the AFAP family, suggesting that they perform fundamental functions shared among family members[42][53]. PH domains are approximately 120 amino acids in length and form characteristic three-dimensional structures consisting of two perpendicular anti-parallel beta sheets followed by a C-terminal amphipathic helix[53]. While many PH domains bind to phosphatidylinositol lipids within biological membranes, including phosphatidylinositol (3,4,5)-trisphosphate and phosphatidylinositol (4,5)-bisphosphate, many PH domains in proteins like AFAP1L1 have limited direct lipid binding capacity and instead function as protein binding modules[53].

However, AFAP1L1 exhibits critical differences in its SH3 binding motif compared to AFAP1, which profoundly influences its binding selectivity[14][20]. Whereas AFAP1 contains two juxtaposed SH3 binding motifs beginning at amino acids 65 and 76 (PPQMPLPEIP and PPDSGPPPLP), AFAP1L1 contains only one predicted SH3 binding motif, DLPPPLPNKP[14][20]. This single SH3 binding motif in AFAP1L1 does not conform to the consensus c-Src SH3 binding motif but rather more closely resembles the binding site for the cortactin SH3 domain, which preferentially binds a +PPΨPXKPXWL motif where + represents a basic residue, Ψ represents an aliphatic residue, and X represents any amino acid[14][20]. This structural difference is functionally significant, as it renders AFAP1L1 capable of efficiently interacting with cortactin through its SH3 domain while being less efficient at binding to c-Src, in stark contrast to AFAP1's preferential c-Src binding[14][20][25].

Regarding tyrosine phosphorylation sites, AFAP1L1 shares 100 percent sequence identity with both AFAP1 and AFAP1L2/XB130 in its predicted N-terminal SH2 binding motif, YYEEA, and is highly similar in its C-terminal SH2 binding motif YDYV[32]. These sequences likely represent potential sites for tyrosine phosphorylation, which could enable the protein to serve as a phosphotyrosine-dependent recruiter of other signaling proteins containing SH2 domains. The serine and threonine-rich sequences flanking the PH domains in AFAP1L1 represent predicted sites for serine/threonine phosphorylation, similar to AFAP1 where serine 277 is a known target of phosphorylation by the protein kinase PKCα, which plays a role in the protein's ability to regulate podosome formation and lifespan[32]. While AFAP1L1 contains similar serine and threonine residues in the sequence flanked by its PH domains, including what may be a PKCα phosphorylation site similar to that of AFAP1, these sequences have not yet been confirmed to be phosphorylated by serine/threonine protein kinases[32].

Actin-Binding Domain and Leucine Zipper Motif

AFAP1L1 possesses a putative actin binding domain at its carboxy terminus that is structurally similar to the known actin filament binding domain found in AFAP1[14][20]. Like AFAP1, which is known to bind actin filaments through its carboxy terminal actin filament-binding domain and multimerize through its leucine zipper to enable actin filament cross-linking[14][20][25], AFAP1L1 contains a similar sequence that may act as a leucine zipper or coiled-coil motif directly adjacent to the actin binding domain[14][20]. The leucine zipper motif is essential for intra-molecular regulation and interaction with other AFAP1L1 molecules, enabling the protein to form higher-order oligomeric complexes[14][20]. This structural feature suggests that AFAP1L1 shares with AFAP1 the capacity to directly interact with and potentially cross-link actin filaments, though the precise mechanisms and substrate specificity may differ between family members.

Protein Interactions and Binding Partners

Cortactin Interaction and Recruitment

AFAP1L1 was first comprehensively characterized as a novel adaptor protein that distinctly interacts with cortactin rather than c-Src, establishing a new functional specialization within the AFAP family[8][13][14][16]. In comparative binding studies using GST fusion proteins, AFAP1L1 was shown to be more efficiently precipitated by GST-SH3-cortactin than by GST-SH3-Src, with approximately a 9-fold increase in the ratio of AFAP1L1 pulled down by GST-cortactin SH3 compared to GST control, whereas AFAP1 showed a strong interaction with the Src SH3 domain with a 14-fold increase in binding and essentially undetectable precipitation by the cortactin SH3 domain[14][20][25]. This differential binding selectivity reflects the structural differences in their SH3 binding motifs and has major consequences for the proteins' cellular roles.

By fluorescence microscopy, AFAP1L1 was demonstrated to decorate actin filaments and move to punctate actin structures while colocalizing with cortactin, consistent with localization to invadosomes—the collective term for both podosomes and invadopodia[8][14][20]. Upon overexpression in smooth muscle A7r5 cells, AFAP1L1 had the ability to induce podosome formation and move to podosomes without stimulation, indicating that AFAP1L1 expression alone is sufficient to drive invadosome assembly in certain cell types[8][14][43]. The specificity of AFAP1L1 for cortactin appears to confer upon it the ability to forge unique protein interactions that may be less efficient with AFAP1, and these interactions potentially allow AFAP1L1 to affect invadosome formation through distinct mechanisms[8][14][43].

Vinculin Interaction and Focal Adhesion Regulation

AFAP1L1 was identified as a novel associating partner of vinculin through immunoprecipitation assays in colorectal cancer cells[7][10][21]. Vinculin is an adaptor protein that localizes to integrin-mediated cell-matrix adhesions such as focal adhesions and invadopodia[7][10][21]. Vinculin functions to stabilize focal adhesions and has been described as a suppressor of cellular migration[7][10][21]. The interaction of AFAP1L1 with vinculin is particularly interesting because it occurs in the ringed structure of invadopodia, where both proteins colocalize[7][10][21].

The ectopic overexpression of AFAP1L1 induces the detachment of vinculin from focal adhesions in both colorectal cancer RKO cells and osteosarcoma SaOS2 cells, an effect that probably reflects the disassembly of focal adhesion structures[7][21][55]. The disassembly of focal adhesions can lead to alterations in both cell shape and motility, presumably as a consequence of reduced cell-matrix contacts, and this disassembly generally coincides with the dynamic formation of podosomes and invadopodia[7][21][55]. The hypothesis has been proposed that the AFAP1L1-induced alterations in cell shape and motility are mediated through its interactions with vinculin[7][10][21]. The mechanism by which AFAP1L1 regulates the function of vinculin remains incompletely understood, but it appears to involve sequestration or competitive displacement of vinculin from its typical focal adhesion localization.

Nck2 Interaction and Actin Nucleation

More recent evidence has demonstrated that AFAP1L1 interacts with Nck2, an adaptor protein containing three SH3 domains that link receptor tyrosine kinases to effectors modulating actin polymerization[48][49]. In sarcoma cells, Nck2 binds to phosphorylated AFAP1L1 to enhance formation of invadopodia[48]. This interaction is particularly interesting because Nck proteins link activated receptor tyrosine kinases and cytosolic substrates to the Arp2/3 complex through N-WASP or related actin nucleation-promoting factors[49]. The N-WASP–Arp2/3 complex is a major driver of branched actin polymerization and is essential for invadopodial structure formation[49]. The interaction between AFAP1L1 and Nck2 thus provides a mechanism through which AFAP1L1 can recruit actin nucleation machinery to sites of invadopodia, amplifying the local concentration of factors necessary for actin polymerization and invadopodial growth.

Rho GTPase Pathway Interactions

Recent research has uncovered that AFAP1L1 interacts with VAV2 (VAV guanine nucleotide exchange factor 2) to activate the Rho family GTPase CDC42[12][19][36][51][57]. In gastric cancer cells, this VAV2-CDC42 axis represents a critical downstream mechanism through which AFAP1L1 promotes cancer cell progression. The interaction between AFAP1L1 and VAV2 ultimately leads to activation of CDC42, a small GTPase of the Rho subfamily, which promotes the expression and activation of integrin subunit alpha 5 (ITGA5) and subsequent integrin signaling pathway activation[12][19][36][51][57]. This VAV2-CDC42-ITGA5 signaling cascade is particularly critical for epithelial-to-mesenchymal transition (EMT) induction, a fundamental process driving cancer cell invasion and metastasis[12][19][36][51][57].

Cellular Localization and Subcellular Structures

Tissue Expression Patterns

AFAP1L1 is expressed in breast, colon, and brain tissues, and in all three tissues it is expressed in the microvasculature at the protein level[17][30][38]. In the breast, AFAP1L1 is found in the contractile myoepithelial cell layer which surrounds the breast ducts and in the microvasculature, localization patterns similar to but distinct from AFAP1[25][38]. In the colon, AFAP1L1 is present in the epithelial mucous membrane, including in the colonic crypts which aid in mucous production and generation of new epithelial cells for the intestinal surface[25][38].

Human brain tissue shows particularly differential expression patterns between AFAP1 and AFAP1L1[25][38]. While AFAP1 is found in the microvasculature of the brain, in the molecular layer and meningeal vessels and to a slight level around the granule cells of the granular layer, AFAP1L1 is found in low levels in the microvasculature but is distinctly localized around Purkinje neurons and the granule cells of the granular layer[25][38]. This AFAP1L1 immunolabeling is not inside the Purkinje neurons or granule cell bodies but instead extends away from the cell body[25][38]. Outside the cerebellar cortex, both AFAP1 and AFAP1L1 are found in glial cells, but they display differential expression patterns in the dentate nucleus, one of four deep cerebellar nuclei responsible for voluntary movements of the extremities[25][38]. The unique localization of AFAP1L1 in the dentate nucleus and its expression appearing to occur along neuronal processes suggests AFAP1L1 has a unique role in the innervation of this nucleus[38][42], potentially related to neuronal process dynamics or axonal guidance.

Podosomes and Invadopodia Localization

AFAP1L1 specifically localizes to podosomes and invadopodia, which are specialized actin-rich adhesion structures formed on the ventral membrane of cells[7][10][14][21]. Podosomes are found primarily on the ventral membrane of cells and contain an F-actin-rich core[14][25][38][43]. Invadopodia, or invadosomes as they are collectively termed with podosomes, are highly dynamic protrusions at the substrate-contacting side of the cell involved in the degradation of the extracellular matrix[7][21][55]. These structures display proteolytic activity induced mainly by the recruitment of matrix metalloproteinases, especially membrane type 1 matrix metalloprotease (MT1-MMP), MMP-2, and/or MMP-9[7][21][37].

AFAP1L1 was specifically reported to be localized to the invadopodia along with cortactin in breast cancer cells[7][21][15], and this localization has been confirmed in multiple other cancer cell types[7][10][21]. In colorectal cancer cells, AFAP1L1 was clustered in the ringed structure of the invadopodia, with detailed immunofluorescence analysis revealing that AFAP1L1 aggregates at the ring-like structure and colocalizes with cortactin, which localizes to the core of the invadopodium[7][21]. The cortactin-rich core of invadopodia contains actin polymerization machinery including the Arp2/3 complex, while the ring is enriched in molecules like paxillin, which regulates adhesion dynamics[7][21].

Upon cSrc binding and activation, AFAP1 and cSrc move to these podosomes, structures which secrete proteases that enable cells to degrade the extracellular matrix, cross tissue barriers, and invade[14][25]. AFAP1L1, while not activating cSrc to the same extent as AFAP1, localizes to these structures through its cortactin interaction, serving distinct functions in invadopodial regulation and formation[8][14][20][43].

Stress Fiber Localization

Beyond its localization to invadosomes, AFAP1L1 decorates actin stress fibers throughout the cell[8][14][20][25][38][43]. AFAP1L1 was shown by fluorescence microscopy to decorate actin filaments and move to punctate actin structures and colocalize with cortactin[8][14][20]. This broader actin cytoskeleton localization suggests that AFAP1L1 serves roles in actin filament remodeling and integrity throughout the cell, not just at invadosomal structures, though its effects on cellular morphology and motility appear to be most pronounced through its actions at invadopodia.

Primary Cellular Functions

Regulation of Cell Morphology and Motility

One of the most striking and well-characterized functions of AFAP1L1 is its ability to profoundly regulate cell morphology through modulation of the actin cytoskeleton. When AFAP1L1 is overexpressed in colorectal cancer RKO cells, which normally exhibit either a predominantly flattened or elongated shape, the cellular morphology becomes drastically altered to a rounded shape[7][10][21][55]. This morphological transition from a mesenchymal-like flattened morphology to a rounded morphology is characteristic of cells undergoing transition toward an amoeboid migration mode, where cells lack mature focal adhesions and stress fibers and instead move through space using their rounded cellular shape[10][21].

This morphological change is not dependent on fibronectin coating of the substrate, as equivalent experiments conducted without fibronectin coating showed similar results[10][21][55]. To confirm that the morphological effect is specifically attributable to AFAP1L1, cells were treated with small interfering RNA (siRNA) against AFAP1L1, which led to reversion to a flattened morphology[10][21][55], demonstrating the sufficiency and necessity of AFAP1L1 expression for maintaining the rounded morphology. Notably, this morphological transition is accompanied by disassembly of focal adhesion structures, as evidenced by the loss of paxillin and vinculin at focal adhesion sites and the disorganization of actin stress fibers[7][10][21][55].

Beyond morphological changes, AFAP1L1 overexpression leads to increased cell motility on planar substrates[7][10][21][55]. When gastric cancer cells with AFAP1L1 overexpression were compared to control cells in Transwell migration and invasion assays, AFAP1L1 downregulation significantly decreased migratory (fold changes = 0.81) and invasive (fold changes = 0.74) capacity of gastric cancer AGS cells, while AFAP1L1 overexpression significantly increased migration (fold changes = 1.26) and invasion (fold changes = 1.33) of MKN74 cells[12][19][36][51]. This enhanced motility likely reflects both the morphological changes enabling amoeboid migration and the disruption of adhesive structures that would otherwise constrain cell movement.

Promotion of Anoikis Resistance

A particularly important function of AFAP1L1 identified through in vitro and in vivo studies is its role in promoting resistance to anoikis, a form of programmed cell death triggered by loss of cell-matrix attachment[7][10][21]. Anoikis represents a critical barrier to cell survival during the early stages of metastatic dissemination, when detached cells are particularly vulnerable to death[7][21][37]. AFAP1L1-transduced colorectal cancer cells exhibited significant resistance to anoikis in vitro[7][10][21]. This anoikis resistance was further confirmed by a decrease in the TUNEL-positive rates (measuring apoptotic cells) in AFAP1L1-expressing cells[7][21]. The resistance to anoikis likely results from the ability of AFAP1L1 to disassemble focal adhesions and reduce cell-matrix contacts, paradoxically protecting cells from the death signals normally triggered by loss of adhesion[7][21][37].

The in vivo significance of this anoikis resistance became apparent when cells were injected as a suspension into mice for xenograft formation[7][21][37]. Subcutaneous injections of cell suspensions in phosphate-buffered saline (PBS) are highly likely to evoke significant increases in anoikis-related signaling cascades. However, AFAP1L1-expressing cells, due to their acquired resistance to anoikis, survive this critical early step of xenograft formation and consequently grow faster in vivo than control cells[7][21][37]. This demonstrates that the adverse impact of upregulated AFAP1L1 expression on treatment outcomes in colorectal cancer may be attributable to enhanced cell motility and increased anoikis resistance, rather than to enhanced invasion capability through degradation of the surrounding matrix[7][21][37].

Invadopodium Formation and Maintenance

AFAP1L1 plays a direct role in the formation and maintenance of invadopodia, specialized cellular protrusions involved in extracellular matrix degradation and invasion[8][14][20][43]. When AFAP1L1 is overexpressed in A7r5 cells, it has the ability to induce podosome formation and move to podosomes without stimulation[8][14][43]. Similarly, osteosarcoma SaOS2 cells transiently expressing AFAP1L1 develop several podosome-like actin-rich dots, structures which are seldom observed in mock-transfected cells[7][21][55]. In most cells expressing AFAP1L1, focal adhesion structures are disassembled, and actin stress fibers are disorganized[7][21][55]. This transition from stress fiber-dominated actin organization to podosome/invadopodia-dominated organization represents a fundamental shift in cellular architecture that facilitates the invasion phenotype.

The molecular mechanism through which AFAP1L1 drives invadopodia formation appears to involve its interaction with cortactin, which recruits the Arp2/3 complex, a central driver of branched actin polymerization[8][14][20][43]. Additionally, AFAP1L1's interaction with Nck2, which links to N-WASP and the Arp2/3 complex, provides another pathway for recruitment of actin nucleation machinery to sites of invadopodia formation[48][49]. The disruption of focal adhesions through AFAP1L1's interaction with vinculin removes a structural barrier to invadopodia assembly, as focal adhesions and invadopodia occupy distinct cellular niches and represent competing actin-based cellular architectures.

Epithelial-to-Mesenchymal Transition (EMT) Promotion

A critical function of AFAP1L1 in cancer cells is its role in promoting epithelial-to-mesenchymal transition (EMT), a fundamental cellular process driving cancer cell invasion and metastasis[12][19][36][51][57]. EMT is often accompanied by reorganization of the cytoskeleton, which is necessary to destroy cell-cell attachment and strengthen cell-matrix adhesions[12]. AFAP1L1 could regulate cytoskeleton rearrangement and thereby facilitate EMT.

In gastric cancer cells, AFAP1L1 downregulation promotes expression of epithelial markers E-cadherin and EPCAM while inhibiting mesenchymal markers vimentin and N-cadherin[12][19][36][51]. Conversely, AFAP1L1 overexpression reduces the expression of epithelial markers and increases the expression of mesenchymal markers in gastric cancer cells[12][19][36][51]. The molecular mechanism underlying AFAP1L1-driven EMT in gastric cancer involves its interaction with VAV2 to activate CDC42, which promotes expression of integrin subunit alpha 5 (ITGA5) and activation of integrin signaling pathways[12][19][36][51][57]. Integrin signaling, particularly through ITGA5, is well-established to promote EMT and enhance cell invasion, providing a mechanistic link between AFAP1L1 expression and the acquisition of invasive capabilities[12][19][36][51].

The occurrence of EMT is often accompanied by reorganization of the cytoskeleton that is necessary to destroy cell-cell attachment and strengthen cell-matrix adhesions[12]. Because AFAP1L1 regulates cytoskeleton rearrangement, its role in facilitating EMT is well-integrated with its other functions in modulating actin dynamics and promoting cell motility. Through these coordinated effects on cellular morphology, adhesion structures, and cytoskeletal organization, AFAP1L1 orchestrates the cellular transformations necessary for epithelial cancer cells to acquire invasive and metastatic capabilities.

Role in Cancer Progression and Metastasis

Colorectal Cancer

AFAP1L1 was initially identified as a metastasis-predicting marker for spindle cell sarcomas through gene expression profiling, but its role in cancer progression was subsequently discovered to extend far beyond sarcomas to affect multiple epithelial malignancies including colorectal cancer[7][10][21][24][31][56]. A marked elevation of AFAP1L1 gene expression was found in colorectal cancer (CRC) tissues compared to adjacent normal mucosa[7][10][21][40][54]. Multivariate analysis revealed that AFAP1L1 expression was an independent and significant factor for the recurrence of rectal cancers[7][10][21][40][54]. Furthermore, the addition of the AFAP1L1 expression level to the lymph node metastasis status provided more predictive information regarding postoperative recurrence in rectal cancers than lymph node status alone[7][10][21][40][54].

In vivo, AFAP1L1-transduced colorectal cancer cells showed accelerated tumor growth, presumably reflecting the anoikis resistance of these AFAP1L1-expressing cells[7][10][21][37][40][54]. Furthermore, the local administration of siRNA against AFAP1L1 significantly suppressed the in vivo tumor growth of xenografts[7][10][21][37][40][54], providing direct experimental evidence that AFAP1L1 represents a viable therapeutic target for colorectal cancers. These results suggest that AFAP1L1 plays a role in the progression of colorectal cancers by modulating cell shape and motility and by inhibiting anoikis, presumably through interactions with vinculin-containing protein complexes[7][10][21][40][54].

Gastric Cancer

More recent comprehensive analysis has revealed that AFAP1L1 functions as a critical oncogenic driver in gastric cancer, representing the only member of the AFAP family to be significantly upregulated in gastric cancer compared with normal gastric tissues[12][19][36][51][57]. Only AFAP1L1 was associated with poor prognosis and was identified as an independent risk factor for overall survival in gastric cancer patients[12][19][36][51][57]. In vitro and in vivo experiments demonstrated that AFAP1L1 promoted gastric cancer cell proliferation, invasion, and metastasis by inducing epithelial-to-mesenchymal transition[12][19][36][51][57].

The mechanism through which AFAP1L1 drives gastric cancer progression involves its interaction with VAV2 to activate CDC42, which promotes expression of integrin subunit alpha 5 (ITGA5) and activation of integrin signaling[12][19][36][51][57]. AFAP1L1 knockdown in AGS gastric cancer cells significantly inhibited their proliferation, while overexpression of AFAP1L1 in MKN74 cells significantly promoted proliferative capacity[12][19][36][51][57]. Transwell migration and invasion assays demonstrated that AFAP1L1 downregulation significantly decreased migratory (fold changes = 0.81) and invasive (fold changes = 0.74) capacity, while AFAP1L1 overexpression significantly increased migration (fold changes = 1.26) and invasion (fold changes = 1.33)[12][19][36][51][57]. In vivo subcutaneous mouse models showed that AFAP1L1 downregulation inhibited growth of subcutaneous tumors, while AFAP1L1 overexpression promoted tumor growth[12][19][36][51][57]. In vivo metastatic experiments showed that knockdown of AFAP1L1 in gastric cancer cells significantly inhibited formation of pulmonary and liver metastasis foci, with MKN74 cells with AFAP1L1 overexpression metastasizing more easily to lung and liver compared to control cells[12][19][36][51][57].

Sarcomas and Other Malignancies

AFAP1L1 was originally identified as a metastasis-predicting marker for spindle cell sarcomas, including osteosarcoma, liposarcoma, and leiomyosarcoma[7][10][24][31][45][56]. In univariate and multivariate analyses, higher expression of AFAP1L1 was found to contribute to the occurrence of distant metastases in sarcomas, along with patient age and tumor grade[24][31][56]. Knockdown of the AFAP1L1 gene in sarcoma cells reduced cell invasiveness, while forced expression of AFAP1L1 in immortalized human mesenchymal stem cells increased anchorage-independent cell growth as well as cell invasiveness[24][31][56]. Gelatin zymography demonstrated increased MMP-9 secretion in AFAP1L1-overexpressed cells, suggesting that AFAP1L1 also promotes the secretion of proteolytic enzymes involved in extracellular matrix degradation[7][10][21][24][31][37].

AFAP1L1 has also been documented to promote cell proliferation, cell cycle progression and inhibit cell apoptosis in non-small cell lung cancer[36][51][57]. The emerging pattern across multiple cancer types suggests that AFAP1L1 functions as a general driver of cancer progression through its ability to modify cellular morphology, promote motility and invasion, facilitate EMT, and enhance anoikis resistance.

Signaling Pathways and Molecular Mechanisms

The VAV2-CDC42-ITGA5 Signaling Axis

Recent mechanistic studies have revealed that AFAP1L1 functions as a critical upstream regulator of the VAV2-CDC42-ITGA5 signaling axis in gastric cancer[12][19][36][51][57]. AFAP1L1 interacts with VAV2, a guanine nucleotide exchange factor for Rho family GTPases[12][19][36][51][57]. This interaction allows VAV2 to catalyze the nucleotide exchange on CDC42, converting it from its inactive GDP-bound state to its active GTP-bound state[12][19][36][51][57]. Once activated, CDC42, a small GTPase of the Rho subfamily, promotes the expression and activation of integrin subunit alpha 5 (ITGA5) and downstream integrin signaling[12][19][36][51][57].

Integrin signaling, particularly through ITGA5 (α5β1 integrin), is well-established to promote cell-matrix adhesion, cell migration, invasion, and epithelial-to-mesenchymal transition[12][19][36][51][57]. The ITGA5 integrin interacts with extracellular matrix proteins containing Arg-Gly-Asp (RGD) sequences, including fibronectin, and transmits signals into the cell that promote motility and survival. Through this signaling pathway, AFAP1L1 expression drives gastric cancer cell proliferation, migration, invasion, and metastasis[12][19][36][51][57].

Cytoskeleton Remodeling and Focal Adhesion Dynamics

AFAP1L1 regulates cytoskeleton remodeling through multiple mechanisms that collectively drive the transition from stress fiber-dominated actin organization to invadopodia-dominated organization[7][10][12][21][55]. The protein's direct binding to actin filaments through its carboxy-terminal actin binding domain enables it to influence actin polymer dynamics[14][20]. Its interaction with cortactin, which recruits the Arp2/3 complex, allows AFAP1L1 to nucleate branched actin polymerization at sites of invadopodia[8][14][20][43][48]. Its interaction with Nck2 provides an additional link to actin nucleation machinery through the N-WASP pathway[48][49].

Perhaps equally important is AFAP1L1's ability to promote focal adhesion disassembly through its interaction with vinculin[7][10][21]. The detachment of vinculin from focal adhesions, induced by AFAP1L1 overexpression, reflects the disassembly of these structures and leads to alterations in cell shape and motility as a consequence of reduced cell-matrix contacts[7][21][55]. This reduction in focal adhesion-mediated cell-matrix adhesion removes a barrier to cell motility and enables the transition to amoeboid migration. Furthermore, focal adhesion disassembly and invadopodia assembly are alternative cellular states—both involve actin reorganization but toward different structural ends—and AFAP1L1 simultaneously promotes both the disassembly of focal adhesions and the assembly of invadopodia, coordinating these complementary processes.

Rho GTPase Regulation

The Rho family of small GTPases, including RhoA, Rac1, and CDC42, play critical roles in the regulation of the actin cytoskeleton, including cell shape and migration[10][21]. It is well-established that Rho-GTPases definitely play a critical role in the regulation of the actin cytoskeleton, including cell shape and migration[10][21]. AFAP1L1 integrates into Rho-GTPase signaling primarily through its interaction with VAV2 and activation of CDC42, though additional interactions with other regulators of Rho GTPases may also occur. CDC42 activation by the VAV2-AFAP1L1 complex promotes actin polymerization through N-WASP and the Arp2/3 complex, driving the formation of branched actin networks characteristic of invadopodia and contributing to cell motility[12][19][36][51][57].

Transcriptional Regulation of AFAP1L1

Sp3 Transcription Factor Control

The expression of AFAP1L1 is tightly controlled at the transcriptional level through the action of the transcription factor Sp3 (specificity protein 3)[31][56][59]. Overexpression of Sp1 and Sp3 proteins transactivated the proximal AFAP1L1 promoter construct, and electrophoretic mobility shift assays showed that both Sp1 and Sp3 were able to bind to the promoter region in vitro[31][56][59]. Chromatin immunoprecipitation experiments, however, revealed that Sp3 is the major factor binding to the proximal promoter region of the AFAP1L1 gene in AFAP1L1-positive cells[31][56][59].

Treatment with mithramycin A, an inhibitor of proteins binding to GC-rich regions, prevented Sp3 from binding to the proximal promoter region of AFAP1L1 and decreased its expression in a dose-dependent manner[31][56][59]. Importantly, knocking down Sp3 using small inhibitory RNA significantly reduced AFAP1L1 expression, which was partially restored by expressing siRNA-resistant Sp3[31][56][59]. These findings indicate a direct and dominant role for Sp3 in driving AFAP1L1 expression in sarcomas and other cell types.

The Sp3 transcription factor is a member of the specificity protein family that binds to GC-rich promoter regions and regulates the transcription of genes involved in various cellular processes, including differentiation, proliferation, and apoptosis[31][56][59]. Sp3 is distinguished from other family members by its particular role in cell differentiation and its sensitivity to certain cellular signals and stresses. The identification of Sp3 as the key transcriptional regulator of AFAP1L1 suggests that signaling pathways that regulate Sp3 activity or expression—including stress responses, growth factor signaling, and differentiation signals—may control AFAP1L1 expression levels in cancer cells and contribute to the transition to an invasive phenotype.

Ets Transcription Factor Involvement

In addition to Sp3, the Ets family of transcription factors also appears to participate in the transcriptional regulation of AFAP1L1[31][56][59]. Luciferase assays suggested the involvement of the Ets protein family in the regulation of AFAP1L1 transcription, and transfection of a dominant-negative Ets vector significantly reduced AFAP1L1 promoter activity[31][56][59]. This suggests that Ets proteins cooperate with Sp3 to drive AFAP1L1 transcription, though Sp3 appears to be the dominant factor. Interestingly, transfection of ELK1, another member of the Ets family, actually reduced AFAP1L1 promoter activity, suggesting that different Ets family members may have distinct, and sometimes opposing, roles in regulating AFAP1L1 transcription[31][56][59].

The involvement of both Sp and Ets transcription factors suggests that AFAP1L1 expression is regulated by signaling pathways that activate these transcription factors, including both basal growth signaling and stress-responsive signaling cascades. This regulatory architecture positions AFAP1L1 as a gene whose expression responds to cellular stress and growth factor signals, consistent with its role as a driver of cancer cell phenotypes under stress conditions such as matrix detachment.

Associated Diseases and Genetic Pathology

Coffin-Siris Syndrome 8

In addition to cancer, mutations in the AFAP1L1 gene have been associated with Coffin-Siris Syndrome 8 (CSS8), a congenital disorder characterized by impaired intellectual development, speech impairment, hypotonia (low muscle tone), feeding difficulties, and behavioral abnormalities[1][26][29]. Dysmorphic features such as hypertrichosis (excessive body hair), thick eyebrows, thin upper lip vermilion, and an upturned nose may be present[26][29]. Additional features include coarse facial features, malformations of various organ systems, and absent or hypoplastic fifth digit nails or phalanges[26][29]. Patients often experience sucking and feeding difficulties, poor growth, ophthalmologic abnormalities, hearing impairment, and spinal anomalies[26][29].

The precise mechanisms through which AFAP1L1 mutations cause Coffin-Siris Syndrome 8 remain to be fully elucidated, but the phenotype suggests that AFAP1L1 is essential for normal neurological development, potentially through its roles in regulating cytoskeletal dynamics in developing neurons. The brain expression of AFAP1L1, particularly in Purkinje cells and around granule cells of the cerebellar granular layer, suggests involvement in cerebellar development and function, which may explain some of the neurological manifestations of CSS8.

Spindle Cell Sarcoma

As noted above, AFAP1L1 is strongly associated with spindle cell sarcomas, including osteosarcoma, liposarcoma, and leiomyosarcoma[1][45]. These associations suggest that AFAP1L1 dysregulation contributes to the malignant transformation and progression of these sarcomas.

Therapeutic Implications and Future Directions

AFAP1L1 as a Therapeutic Target

The evidence that AFAP1L1 promotes cancer progression across multiple cancer types, combined with the finding that local administration of siRNA against AFAP1L1 significantly suppresses in vivo tumor growth, suggests that AFAP1L1 represents a promising therapeutic target for cancer treatment[7][10][21][37][40][54]. The fact that AFAP1L1 expression is an independent prognostic factor for cancer recurrence and poor survival further supports its development as a therapeutic target.

Several strategies could be pursued to target AFAP1L1 in cancer therapy. Direct knockdown using antisense oligonucleotides or siRNA could reduce AFAP1L1 expression in cancer cells. Small molecule inhibitors targeting the protein-protein interactions through which AFAP1L1 exerts its effects—such as its interactions with cortactin, vinculin, VAV2, Nck2, or actin—could potentially disrupt AFAP1L1 function without completely eliminating the protein. Transcriptional inhibition of AFAP1L1 expression through Sp3 inhibitors or other approaches targeting Sp3-AFAP1L1 promoter interactions could prevent upregulation of AFAP1L1 in cancer cells.

Biomarker Development

AFAP1L1 expression levels show promise as a prognostic biomarker for cancer recurrence and poor survival across multiple cancer types[7][10][12][19][21][36][40][51][54][57]. The addition of AFAP1L1 expression to standard clinicopathologic factors such as lymph node metastasis status provides more predictive information regarding cancer recurrence and overall survival than these factors alone[7][10][21][40][54]. Development of standardized methods for AFAP1L1 assessment (such as immunohistochemistry scoring systems or qPCR assays) and validation in large clinical cohorts could establish AFAP1L1 as a clinical biomarker that guides treatment decisions and prognostic counseling.

Conclusion

AFAP1L1 has emerged as a critical regulator of cancer cell invasion, metastasis, and epithelial-to-mesenchymal transition through its multiple roles in modulating actin cytoskeleton dynamics, controlling cell-matrix adhesion, and regulating fundamental processes like anoikis resistance and cell motility. As a multidomain adaptor protein, AFAP1L1 integrates signals from multiple upstream pathways—including growth factor signaling through receptor tyrosine kinases, integrin signaling, and Rho GTPase cascades—and translates these signals into coordinated changes in cellular morphology and migration capacity. The protein's specific interactions with cortactin, rather than c-Src as seen with its family member AFAP1, provide a specialized niche within the adaptor protein family that positions AFAP1L1 as a coordinator of invadopodia formation and podosome assembly, key structures driving invasion and metastasis[7][10][12][14][20][21][36][51].

The discovery of the VAV2-CDC42-ITGA5 signaling axis downstream of AFAP1L1 provides a molecular framework for understanding how AFAP1L1 promotes epithelial-to-mesenchymal transition and the acquisition of invasive capabilities in epithelial cancers[12][19][36][51][57]. The identification of Sp3 as the major transcriptional regulator of AFAP1L1 offers potential strategies for controlling AFAP1L1 expression through targeting Sp3 or its upstream regulators. The robust evidence that AFAP1L1 knockdown suppresses tumor growth in vivo and that AFAP1L1 expression independently predicts cancer recurrence and poor survival establish this protein as a promising therapeutic target and biomarker for multiple cancer types. Future research should focus on developing specific inhibitors of AFAP1L1 function, understanding the upstream signaling pathways that regulate AFAP1L1 expression in cancer contexts, validating AFAP1L1 as a clinical biomarker in prospective trials, and exploring combination therapeutic strategies that target AFAP1L1 together with other cancer drivers. Through these efforts, AFAP1L1 may become both a key biomarker guiding cancer patient stratification and a crucial target for developing new therapies to suppress cancer invasion and metastasis.

Citations

1. https://www.genecards.org/cgi-bin/carddisp.pl?gene=AFAP1L1
2. https://maayanlab.cloud/Harmonizome/gene_set/Actin+filament-associated+protein+1-like+1/InterPro+Predicted+Protein+Domain+Annotations
3. https://functionome.geneontology.org/gene/UniProtKB:Q8TED9
4. https://www.proteinatlas.org/ENSG00000157510-AFAP1L1
5. https://www.informatics.jax.org/marker/MGI:2147199
6. https://www.uniprot.org/locations/SL-0501
7. https://onlinelibrary.wiley.com/doi/full/10.1002/cam4.237
8. https://pubmed.ncbi.nlm.nih.gov/21333378/
9. https://diseases.jensenlab.org/Entity?documents=10&type1=9606&id1=ENSP00000296721&type2=-26&id2=DOID%3A4235
10. https://pmc.ncbi.nlm.nih.gov/articles/PMC4303145/
11. https://www.uniprot.org/uniprotkb/Q8TED9/entry
12. https://pmc.ncbi.nlm.nih.gov/articles/PMC9835296/
13. https://pmc.ncbi.nlm.nih.gov/articles/PMC3085893/
14. https://researchrepository.wvu.edu/etd/3379/
15. https://www.ncbi.nlm.nih.gov/gene/998
16. https://geneglobe.qiagen.com/us/knowledge/gene/ENSMUSG00000033032
17. https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0049709
18. https://www.malacards.org/card/coffin_siris_syndrome_8
19. https://maayanlab.cloud/Harmonizome/gene/AFAP1L1
20. https://www.datacommons.org/browser/bio/DOID_0112367
21. https://pmc.ncbi.nlm.nih.gov/articles/PMC3541374/
22. https://pubmed.ncbi.nlm.nih.gov/25301070/
23. https://mhlw-grants.niph.go.jp/system/files/2013/133041/201313047B/201313047B0007.pdf
24. https://stacks.cdc.gov/view/cdc/192171/cdc_192171_DS1.pdf
25. https://pubmed.ncbi.nlm.nih.gov/36631800/
26. https://pmc.ncbi.nlm.nih.gov/articles/PMC4774376/
27. https://www.spandidos-publications.com/10.3892/br.2016.588
28. https://pmc.ncbi.nlm.nih.gov/articles/PMC7737098/
29. https://f1000research.com/posters/1089915
30. https://www.molbiolcell.org/doi/abs/10.1091/mbc.e06-01-0088?etoc=
31. https://pubmed.ncbi.nlm.nih.gov/26212012/
32. https://pmc.ncbi.nlm.nih.gov/articles/PMC10999758/
33. https://pmc.ncbi.nlm.nih.gov/articles/PMC1933402/
34. https://w.string-db.org/overview/overview.59729.html
35. https://en.wikipedia.org/wiki/Pleckstrin_homology_domain
36. https://pubmed.ncbi.nlm.nih.gov/23326307/