ELOVL4 is a Prognostic Biomarker with Implications for Immune Modulation and Therapeutic Response in Gastric Cancer

BACKGROUND: Gastric cancer (GC) remains a major health burden with poor prognosis, highlighting the need for reliable prognostic biomarkers and therapeutic targets. ELOVL4 (Elongation of Very Long Chain Fatty Acids Protein 4) is an enzyme involved in lipid metabolism, which has been implicated in various cancers, but its role in GC remains largely unexplored. METHODS: We evaluated the prognostic value of ELOVL4 expression in GC based on samples from The Cancer Genome Atlas (TCGA) database. Subsequently, we investigated the associations between ELOVL4 expression and tumor immune microenvironment features, including tumor microenvironment (TME) scores, immune cell infiltration, and immune checkpoint gene expression. Moreover, we assessed the correlation between ELOVL4 expression and tumor mutational burden (TMB) as well as drug sensitivity profiles. Functional and pathway enrichment analyses were performed to gain mechanistic insights. RESULTS AND DISCUSSION: High ELOVL4 expression was significantly associated with adverse clinical outcomes. A nomogram incorporating ELOVL4 expression was developed for individualized prognosis evaluation. Patients with high ELOVL4 expression exhibited an activated TME, with distinct immune cell infiltration patterns and correlations with immune checkpoint gene expression. Additionally, ELOVL4 expression was negatively correlated with TMB. Differential drug sensitivity profiles were identified between the high and low ELOVL4 expression groups. Enrichment analyses revealed the involvement of ELOVL4 in various biological processes and signaling pathways. CONCLUSION: Our findings establish ELOVL4 as a biomarker for poor prognosis and therapeutic target in GC, with implications for prognosis evaluation, immune microenvironment modulation, and chemotherapeutic response.