Epigenetic Alterations in Hepatocellular Carcinoma: Mechanisms and Biomarkers for Precision Therapy

Hepatocellular carcinoma (HCC), a leading cause of cancer-related mortality worldwide, is driven by complex interactions between genetic mutations and reversible epigenetic alterations. Among these, aberrant DNA methylation, histone modifications, and dysregulated noncoding RNAs (ncRNAs) play central roles in hepatocarcinogenesis, tumor progression, and therapy resistance. Epigenetic changes not only regulate key oncogenic pathways, including JAK/STAT and RAS, but also contribute to tumor immune evasion and heterogeneity. Unlike genetic mutations, epigenetic alterations are reversible, offering unique opportunities for therapeutic targeting. This review highlights recent advances in understanding the epigenetic landscape of HCC, identifies promising biomarkers for early detection and prognosis, and evaluates emerging epigenetic therapies (including DNMT, HDAC, and BET inhibitors as well as ncRNA-based strategies). Although these therapies have shown tumor-suppressive or treatment-sensitizing effects in preclinical models, their clinical translation remains limited by modest efficacy, small early-phase trials, treatment-related adverse events, and insufficient biomarker-guided patient selection. These insights may support more precise diagnostic and therapeutic strategies for HCC.