Novel miR-15b-5p/BTG2 regulatory axis drives esophageal cancer progression through multi-omics analysis and functional validation

Abstract Background Esophageal cancer (EC), a leading cause of cancer-related mortality, lacks reliable biomarkers for early detection and prognosis. Dysregulated microRNAs (miRNAs) are emerging as pivotal regulators of tumor progression, but their context-specific roles and interactions with target genes in EC remain underexplored. Methods Multi-omics data from TCGA-ESCA and GEO datasets were integrated to identify differentially expressed miRNAs and mRNAs. A miRNA-mRNA regulatory network was constructed using FunRich and validated via functional assays, including dual-luciferase reporter, qRT-PCR, Western blot, and in vitro proliferation/migration/invasion experiments. Prognostic signatures were developed using Cox regression, LASSO modeling, and nomogram analysis. Results We identified 1,131 differentially expressed mRNAs and 69 miRNAs in EC. The miR-15b-5p/BTG2 axis emerged as a central hub in the regulatory network. miR-15b-5p was upregulated in EC tissues and inversely correlated with BTG2 expression. Survival analyses confirmed miR-15b-5p and BTG2 as independent prognostic factors. Mechanistically, miR-15b-5p directly targeted BTG2’s 3'-UTR, suppressing its expression. Functional assays demonstrated that miR-15b-5p overexpression promoted EC cell proliferation, migration, and invasion, while BTG2 restoration reversed these effects. A nomogram integrating miR-15b-5p, BTG2, and clinical parameters showed robust predictive accuracy (C-index: 0.78). Conclusions miR-15b-5p/BTG2 is a novel regulatory axis in the progression of esophageal cancer and has the potential to become a prognostic and diagnostic target of esophageal cancer.