Apoptin-Armed Oncolytic Adenovirus Triggers Apoptosis and Inhibits Proliferation, Migration, Invasion, and Stemness of Hepatocellular Carcinoma Hep3B Cells

Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality, highlighting the urgent need for novel therapeutic strategies. Apoptin, encoded by the VP3 gene of the chicken anemia virus, selectively induces apoptosis in cancer cells while sparing normal cells. We previously engineered a recombinant oncolytic adenovirus (Ad-VP3) capable of high-level Apoptin expression in tumor cells. In this study, we evaluated the antitumor activity of Ad-VP3 in the human HCC cell line Hep3B. CCK-8, crystal violet, Hoechst 33342 staining, flow cytometry, and tumor sphere formation assays revealed that Ad-VP3 inhibited cell viability, proliferation, and stemness. Annexin V staining, JC-1/TMRM probes, and Western blot analysis demonstrated induction of apoptosis and reduction of mitochondrial membrane potential. Wound-healing, Transwell, and BioCoat invasion assays, along with Western blotting, confirmed suppression of migration and invasion. Ad-VP3 significantly inhibited the viability, proliferation, migration, and invasion of Hep3B cells in a time- and dose-dependent manner. It induced mitochondrial membrane potential loss and apoptosis, downregulated stemness-related proteins (ALDH1A1, KLF4, and Sox2), and suppressed epithelial-mesenchymal transition markers (Snail, Twist1, Slug, Vimentin, and MMP-9), indicating strong antitumor activity. The recombinant oncolytic adenovirus Ad-VP3 exerts potent antitumor effects on hepatocellular carcinoma cells by inducing mitochondrial dysfunctionmediated apoptosis and impairing stemness and metastatic potential, suggesting its promise as a novel therapeutic strategy for HCC.