Hepatocellular carcinoma (HCC) remains a significant clinical challenge due to limited diagnostic and therapeutic options. Non-coding RNAs, such as microRNAs (miRNAs), play key roles in cancer biology. Our previous findings showed that miR-423-5p exerts anti-cancer effects on HCC patients treated with sorafenib by promoting autophagy. In this study, we investigated the molecular mechanisms underlying its activity by generating SNU-387 HCC cell line stably overexpressing miR-423-5p and conducting a comprehensive proteomic analysis. Mass spectrometry profiling identified 698 differentially expressed proteins (DEPs) in miR-423-5p-overexpressing cells compared to controls. Functional enrichment analysis revealed significant alterations in metabolic pathways, particularly purine/pyrimidine metabolism and gluconeogenesis. To relate these findings to clinical context, we integrated experimentally validated and predicted miR-423-5p targets with The Cancer Genome Atlas (TCGA) Liver Hepatocellular Carcinoma (LIHC) dataset. Seven candidate proteins were significantly associated with patient prognosis (log-rank p < 0.05 for both overall and disease-free survival). These targets were downregulated in our miR-423-5p model but found to be upregulated in stage III HCC tissues from TCGA data.