GJC1

Overview

GJC1 (gap junction protein gamma 1, also known as connexin 45) encodes a member of the connexin family of gap junction proteins. In neuroblastoma, GJC1 has been identified as a candidate pan-neuroblastoma extracellular vesicle (EV) surface marker by LC-MS/MS proteomics, with high expression correlating with poor prognosis and selective essentiality for neuroblastoma cell survival demonstrated in CRISPR screens.

Alterations observed in the corpus

  • GJC1 identified as a potential pan-neuroblastoma EV surface marker by LC-MS/MS proteomics; its gene locus maps to chromosome 17q21.31, a region gained in approximately 50% of neuroblastomas PMID:22367537
  • High GJC1 expression correlates with poor overall survival (OS) and event-free survival (EFS) in neuroblastoma PMID:22367537
  • GJC1 is selectively essential for neuroblastoma cell survival in CRISPR screens PMID:22367537
  • GJC1 expression in EVs is independent of MYCN amplification status; overexpressed during tumour formation in the TH-MYCN mouse model PMID:22367537

Cancer types (linked)

  • NBL (neuroblastoma): GJC1 is overexpressed in neuroblastoma cell lines (Kelly, SH-EP2, SH-SY5Y) and in TH-MYCN tumour model EVs; high expression is associated with poor prognosis regardless of MYCN amplification status PMID:22367537

Co-occurrence and mutual exclusivity

  • GJC1 EV expression is independent of MYCN amplification status; both MYCN-amplified (Kelly) and non-amplified (SH-EP2, SH-SY5Y) lines express GJC1 on EVs PMID:22367537

Therapeutic relevance

  • GJC1 may serve as a surface marker for immunocapture-based enrichment of circulating neuroblastoma-derived EVs in liquid biopsies, enabling non-invasive tumour monitoring PMID:22367537
  • CRISPR-screen-confirmed essential function suggests GJC1 may be a therapeutic vulnerability in neuroblastoma, though no targeted agent has been reported in the corpus.

Open questions

  • Development of antibodies against GJC1 extracellular epitopes is technically challenging due to small extracellular loops and high sequence similarity across the 21 human connexin isoforms PMID:22367537
  • The functional role of GJC1 in neuroblastoma development and progression remains unexplored beyond its essentiality in CRISPR screens PMID:22367537
  • Clinical validation in patient samples (rather than cell lines) is needed to establish GJC1 utility as a liquid biopsy biomarker PMID:22367537

Sources

This page was processed by entity-page-writer on 2026-05-06.