Mitophagy-related gene signatures predict prognosis and therapeutic response in hepatocellular carcinoma

Mitophagy, a selective form of autophagy, has been implicated in tumor progression and therapeutic resistance; however, its prognostic significance in hepatocellular carcinoma (HCC) remains unclear. In this study, we comprehensively evaluated the role of mitophagy-related genes in HCC using multi-omics data. Gene expression profiles were obtained from the TCGA-LIHC and GSE14520 cohorts, and mitophagy-related genes were retrieved from the GeneCards database. Twenty differentially expressed mitophagy-related genes with prognostic value (pDEMGs) were identified, and consensus clustering stratified HCC patients into two clusters with significantly different survival outcomes (P = 0.001). A mitophagy enrichment score (MIES) was then calculated using single-sample gene set enrichment analysis (ssGSEA). Elevated MIES was associated with poorer overall survival (HR = 2.17, P = 0.005), metabolic activation, immune suppression, and differential drug sensitivity. Single-cell analysis of the GSE140228 dataset revealed heterogeneous MIES activity across cell populations, with relatively higher enrichment observed in proliferating T cells and dendritic cells. A six-gene prognostic signature (ACTR6, GAPDH, ATIC, ANP32E, CCT6A, and BSG) was developed using LASSO-Cox regression, which effectively stratified patients into high- and low-risk groups with distinct overall survival outcomes (1-, 3-, and 5-year AUCs: 0.780, 0.682, and 0.690, respectively). The risk score was correlated with immune infiltration patterns, mutational landscape, and chemotherapy response. qPCR validation further confirmed the upregulation of ACTR6, CCT6A, ATIC, and BSG in HCC cells. Collectively, these findings establish a mitophagy-related scoring system that reflects immune and genomic characteristics, as well as a six-gene signature with independent prognostic value, highlighting the potential clinical relevance of mitophagy in HCC.