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this with annotations you find in gene/protein databases, but these can be outdated or inaccurate.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.

Plan and approach
We verified identity and nomenclature (VOPP1/ECOP/GASP; UniProt Q96AW1; human) and searched for recent primary/review literature (2023–2024). Because dedicated, recent mechanistic work on VOPP1 is sparse, we anchored the report on foundational peer‑reviewed studies and interaction datasets, and we note the recency limitation explicitly (see Expert perspectives). We then synthesized functional roles, localization, pathways, and disease relevance with quantitative data where available.

Table: Compact summary table of VOPP1 identity, interactions, localization, functions, pathway links, disease associations, and key quantitative experimental results with primary citations from the available evidence; useful as a quick reference for mechanistic and translational follow-up.

1) Key concepts and definitions with current understanding
- Gene/protein identity: VOPP1 (HGNC:34518), also known as ECOP (EGFR‑coamplified and overexpressed protein) and GASP (glioblastoma‑amplified secreted protein), encodes a small vesicle‑associated protein implicated in pro‑survival signaling in cancer. The aliases and human specificity match UniProt Q96AW1 and are used consistently in mechanistic literature (e.g., glioma studies) (xia2013mir218sensitizesglioma pages 1-2, dai2019vopp1promoteshepatocellular pages 1-4).
- Subcellular localization and molecular nature: Proteomic interactome mapping places VOPP1 within a network of proteins from ER/Golgi/late endosome/lysosome systems and perinuclear compartments, consistent with a vesicle‑associated or vesicle‑trafficking role rather than an enzyme or transporter. VOPP1 binds the WW domain of the tumor suppressor WWOX via a PPPY motif, supporting a role as a WW‑binding adapter localized to membrane/vesicular pathways (hussain2018delineatingwwoxprotein pages 6-8).
- Core signaling function: Foundational work in glioma identifies ECOP/VOPP1 as a modulator of NF‑κB transcriptional activity that promotes cell survival; miR‑218 directly targets ECOP to suppress NF‑κB activity and sensitize cells to apoptosis (luciferase reporters, rescue experiments) (xia2013mir218sensitizesglioma pages 1-2).

2) Recent developments and latest research (2023–2024 prioritized)
- Direct, VOPP1‑focused mechanistic papers from 2023–2024 are limited in the retrieved evidence. Contemporary reviews continue to cite ECOP/VOPP1 within NF‑κB/EGFR‑linked stress and vesicular signaling contexts, but primary mechanistic advances remain anchored in earlier studies. The newest quantitative work in our evidence set remains a 2019 preprint describing VOPP1‑dependent proliferation pathways in HCC that implicate MAPK14 and RPS6KB1 (mTOR/S6K) (dai2019vopp1promoteshepatocellular pages 1-4, dai2019vopp1promoteshepatocellular pages 11-18, dai2019vopp1promoteshepatocellular pages 7-11, dai2019vopp1promoteshepatocellular pages 4-7).

3) Current applications and real‑world implementations
- Oncology biomarker and target potential: Multiple tumor contexts report VOPP1 overexpression or amplification within the EGFR amplicon, suggesting utility as a tumor biomarker and a candidate therapeutic vulnerability, particularly where NF‑κB signaling contributes to survival. Functional knockdown in HCC reduces proliferation in vitro and suppresses xenograft growth, supporting target plausibility in preclinical models (xia2013mir218sensitizesglioma pages 1-2, dai2019vopp1promoteshepatocellular pages 4-7, dai2019vopp1promoteshepatocellular pages 11-18).

4) Expert opinions and analysis from authoritative sources
- Mechanistic axis: The Neuro‑Oncology study demonstrates that ECOP/VOPP1 is both necessary and sufficient to modulate NF‑κB–dependent survival outputs downstream of miR‑218, providing causal evidence for its role in pro‑survival signaling in glioma cells (xia2013mir218sensitizesglioma pages 1-2). The WWOX interactome work independently positions VOPP1 as a WW domain‑binding partner associated with secretory and endo‑lysosomal trafficking, consistent with a scaffolding/adapter role that can integrate signaling with vesicular compartments (hussain2018delineatingwwoxprotein pages 6-8). Together, these sources support a model in which VOPP1 functions as a vesicle‑associated adaptor that tunes NF‑κB and growth‑factor–adjacent pathways across tumor contexts (xia2013mir218sensitizesglioma pages 1-2, hussain2018delineatingwwoxprotein pages 6-8).
- Pathway linkage in liver cancer: The HCC preclinical study links VOPP1 to MAPK14 (p38) and RPS6KB1 (S6K) abundance and pathway activity after VOPP1 knockdown, aligning VOPP1 with stress‑response and anabolic growth signaling frequently co‑opted in tumors (dai2019vopp1promoteshepatocellular pages 1-4, dai2019vopp1promoteshepatocellular pages 7-11).

5) Relevant statistics and data from recent studies
- HCC knockdown phenotypes (quantitative): VOPP1 knockdown markedly reduced colony formation (e.g., SMMC‑7721 colonies 111 ± 2 vs 18 ± 3; BEL‑7404 168 ± 11 vs 22 ± 4; P<0.01), increased apoptosis (SMMC‑7721 4.48% → 12.47%; BEL‑7404 2.24% → 23.66%; P<0.001), and reduced in vivo xenograft tumor volume/weight (P<0.001), with microarray implicating TNF‑mediated signaling; MAPK14 and RPS6KB1 protein levels decreased upon VOPP1 silencing (dai2019vopp1promoteshepatocellular pages 4-7, dai2019vopp1promoteshepatocellular pages 11-18, dai2019vopp1promoteshepatocellular pages 7-11).

Functional roles and pathways
- NF‑κB modulation: ECOP/VOPP1 enhances NF‑κB activity; loss of ECOP via miR‑218 suppresses NF‑κB target transcription and increases apoptosis. ECOP overexpression rescues NF‑κB activity and cell survival, indicating that ECOP/VOPP1 is a proximal modulator of NF‑κB–dependent transcriptional programs in glioma (xia2013mir218sensitizesglioma pages 1-2).
- EGFR amplicon context and growth signaling: VOPP1 has been described in the EGFR co‑amplified region in glioblastoma, and HCC data connect VOPP1 to MAPK14 (stress kinase) and mTOR/S6K growth pathways, suggesting that VOPP1 integrates vesicle‑associated signaling with proliferative and survival networks (dai2019vopp1promoteshepatocellular pages 1-4, dai2019vopp1promoteshepatocellular pages 7-11).
- Protein–protein interactions: The WWOX–VOPP1 interaction via a WW1–PPPY interface supports a model in which VOPP1 may participate in scaffolding complexes at perinuclear/vesicular compartments linking trafficking to signal transduction (hussain2018delineatingwwoxprotein pages 6-8).

Cellular and subcellular localization
- Evidence for perinuclear ER/Golgi/late endosome/lysosome association comes from WWOX interactome localization and partner enrichment analyses; this aligns with the “vesicular, overexpressed in cancer” nomenclature and supports a role at vesicle membranes where signaling platforms assemble (hussain2018delineatingwwoxprotein pages 6-8).

Disease relevance across indications
- Glioma/glioblastoma: ECOP/VOPP1 is upregulated in glioma and modulates NF‑κB–dependent survival; the miR‑218–ECOP axis reduces tumorigenicity when ECOP is suppressed (xia2013mir218sensitizesglioma pages 1-2).
- Hepatocellular carcinoma: VOPP1 is overexpressed in HCC; knockdown impairs proliferation, increases apoptosis, and reduces xenograft growth, associated with downregulation of MAPK14 and RPS6KB1 (dai2019vopp1promoteshepatocellular pages 1-4, dai2019vopp1promoteshepatocellular pages 11-18, dai2019vopp1promoteshepatocellular pages 4-7).
- Other tumors: Historical reports (referenced within the HCC study) include gastric and squamous cell carcinomas; while not directly quantified here, they support the general pattern of VOPP1 involvement in EGFR‑linked epithelial tumors (dai2019vopp1promoteshepatocellular pages 7-11).

Limitations and open questions (2023–2024 landscape)
- Despite broad citation of ECOP/VOPP1 in reviews, there is limited new primary mechanistic work in 2023–2024 directly dissecting VOPP1 biochemistry, structure, and pathway wiring. Structural definition (domains beyond a PPPY motif), high‑resolution localization, and unbiased dependency screens in modern multi‑omic cohorts remain areas for future research (hussain2018delineatingwwoxprotein pages 6-8, xia2013mir218sensitizesglioma pages 1-2, dai2019vopp1promoteshepatocellular pages 1-4).

Practical implications
- Biomarker potential: Given overexpression in multiple cancers and functional linkage to survival pathways, VOPP1 may serve as an adjunct biomarker within EGFR‑amplicon tumors and HCC; however, standardized assays and prospective validation are needed (xia2013mir218sensitizesglioma pages 1-2, dai2019vopp1promoteshepatocellular pages 1-4).
- Therapeutic strategies: Targeting the VOPP1–NF‑κB axis (e.g., restoring miR‑218 or disrupting VOPP1 scaffolding functions) and exploiting the VOPP1–MAPK14/mTOR connection in HCC are plausible strategies suggested by preclinical data and warrant medicinal chemistry and delivery exploration (xia2013mir218sensitizesglioma pages 1-2, dai2019vopp1promoteshepatocellular pages 7-11, dai2019vopp1promoteshepatocellular pages 11-18).

Source list with URLs and publication dates
- Xia et al., Neuro‑Oncology, April 2013. “MiR‑218 sensitizes glioma cells to apoptosis and inhibits tumorigenicity by regulating ECOP‑mediated suppression of NF‑κB activity.” https://doi.org/10.1093/neuonc/nos296 (xia2013mir218sensitizesglioma pages 1-2).
- Hussain et al., Frontiers in Oncology, December 2018. “Delineating WWOX Protein Interactome by Tandem Affinity Purification‑Mass Spectrometry: Identification of Top Interactors and Key Metabolic Pathways Involved.” https://doi.org/10.3389/fonc.2018.00591 (hussain2018delineatingwwoxprotein pages 6-8).
- Dai et al., Research Square/ArXiv preprint, July 2019. “VOPP1 promotes hepatocellular carcinoma proliferation through MAPK14 and RPS6KB1.” https://doi.org/10.21203/rs.2.11083/v1 (dai2019vopp1promoteshepatocellular pages 1-4, dai2019vopp1promoteshepatocellular pages 11-18, dai2019vopp1promoteshepatocellular pages 7-11, dai2019vopp1promoteshepatocellular pages 4-7).

Conclusion
VOPP1 (ECOP/GASP; Q96AW1) is a vesicle‑associated adaptor that binds WW domains (e.g., WWOX) and modulates NF‑κB–driven survival programs, with additional links to MAPK14 and mTOR/S6K signaling in HCC. It localizes to perinuclear secretory/endo‑lysosomal compartments and is embedded in the EGFR co‑amplified region in glioblastoma. Functional knockdowns in HCC yield strong anti‑tumor phenotypes, positioning VOPP1 as a biomarker/target candidate in select cancers. Recent primary literature (2023–2024) appears limited, underscoring the need for renewed mechanistic and translational studies (xia2013mir218sensitizesglioma pages 1-2, hussain2018delineatingwwoxprotein pages 6-8, dai2019vopp1promoteshepatocellular pages 1-4).

References

1. (xia2013mir218sensitizesglioma pages 1-2): Hongping Xia, Yukui Yan, Minghua Hu, Yaxian Wang, Yongsheng Wang, Yi Dai, Jianming Chen, Guangfu Di, Xiaobing Chen, and Xiaochun Jiang. Mir-218 sensitizes glioma cells to apoptosis and inhibits tumorigenicity by regulating ecop-mediated suppression of nf-κb activity. Neuro-oncology, 15 4:413-22, Apr 2013. URL: https://doi.org/10.1093/neuonc/nos296, doi:10.1093/neuonc/nos296. This article has 102 citations and is from a domain leading peer-reviewed journal.

2. (dai2019vopp1promoteshepatocellular pages 1-4): Haojiang Dai, Peng Hu, Binfeng Wang, Qiuyue Han, Yongfu Xu, Shangdong Lv, Yu Zhu, Meifu Gan, Weijie Zhou, Zheping Fang, and Wenlong Zhang. Vopp1 promotes hepatocellular carcinoma proliferation through mapk14 and rps6kb1. ArXiv, Jul 2019. URL: https://doi.org/10.21203/rs.2.11083/v1, doi:10.21203/rs.2.11083/v1. This article has 0 citations.

3. (hussain2018delineatingwwoxprotein pages 6-8): Tabish Hussain, Jaeho Lee, Martin C. Abba, Junjie Chen, and C. Marcelo Aldaz. Delineating wwox protein interactome by tandem affinity purification-mass spectrometry: identification of top interactors and key metabolic pathways involved. Frontiers in Oncology, Dec 2018. URL: https://doi.org/10.3389/fonc.2018.00591, doi:10.3389/fonc.2018.00591. This article has 30 citations and is from a poor quality or predatory journal.

4. (dai2019vopp1promoteshepatocellular pages 4-7): Haojiang Dai, Peng Hu, Binfeng Wang, Qiuyue Han, Yongfu Xu, Shangdong Lv, Yu Zhu, Meifu Gan, Weijie Zhou, Zheping Fang, and Wenlong Zhang. Vopp1 promotes hepatocellular carcinoma proliferation through mapk14 and rps6kb1. ArXiv, Jul 2019. URL: https://doi.org/10.21203/rs.2.11083/v1, doi:10.21203/rs.2.11083/v1. This article has 0 citations.

5. (dai2019vopp1promoteshepatocellular pages 11-18): Haojiang Dai, Peng Hu, Binfeng Wang, Qiuyue Han, Yongfu Xu, Shangdong Lv, Yu Zhu, Meifu Gan, Weijie Zhou, Zheping Fang, and Wenlong Zhang. Vopp1 promotes hepatocellular carcinoma proliferation through mapk14 and rps6kb1. ArXiv, Jul 2019. URL: https://doi.org/10.21203/rs.2.11083/v1, doi:10.21203/rs.2.11083/v1. This article has 0 citations.

6. (dai2019vopp1promoteshepatocellular pages 7-11): Haojiang Dai, Peng Hu, Binfeng Wang, Qiuyue Han, Yongfu Xu, Shangdong Lv, Yu Zhu, Meifu Gan, Weijie Zhou, Zheping Fang, and Wenlong Zhang. Vopp1 promotes hepatocellular carcinoma proliferation through mapk14 and rps6kb1. ArXiv, Jul 2019. URL: https://doi.org/10.21203/rs.2.11083/v1, doi:10.21203/rs.2.11083/v1. This article has 0 citations.

Citations

1. hussain2018delineatingwwoxprotein pages 6-8
2. https://doi.org/10.1093/neuonc/nos296,
3. https://doi.org/10.21203/rs.2.11083/v1
4. https://doi.org/10.3389/fonc.2018.00591
5. https://doi.org/10.1093/neuonc/nos296
6. https://doi.org/10.21203/rs.2.11083/v1,
7. https://doi.org/10.3389/fonc.2018.00591,