SILENCING SERPINB3 AS A NOVEL STRATEGY FOR LIVER CANCER

Hepatocellular carcinoma (HCC) persists as a significant global health concern and constitutes a primary cause of cancer-related mortality. It frequently originates within the framework of chronic liver diseases (CLD), such as cirrhosis, viral hepatitis, alcohol-associated liver injury, and non-alcoholic fatty liver disease (NAFLD). Despite progress in multidisciplinary management, encompassing surgical resection, liver transplantation, locoregional therapies, and molecularly targeted systemic treatments, clinical outcomes remain inconsistent and often unsatisfactory. This highlights the need for innovative therapeutic strategies grounded in a deeper understanding of the molecular mechanisms driving liver cancer progression. Serine Protease Inhibitor B3 (SERPINB3), a highly conserved cysteine protease inhibitor, is consistently overexpressed in multiple malignancies, including HCC. Elevated levels of SERPINB3 are associated with poor prognosis, increased invasiveness, and early recurrence of tumors. Functionally, SERPINB3 exerts various oncogenic effects, including the promotion of epithelial mesenchymal transition (EMT), contribution to hepatic fibrogenesis and inflammation, enhancement of TGF-β signaling, and upregulation of oncogenes such as c-Myc. Furthermore, SERPINB3 confers resistance to apoptosis and chemotherapeutic agents by inhibiting mitochondrial reactive oxygen species (ROS) production via its interaction with respiratory Complex I and by maintaining activation of the endoplasmic reticulum (ER) stress-mediated unfolded protein response. It is also implicated in an IL-6/STAT3-dependent feed-forward loop, and recent studies have identified the SERPINB3–PAR2 signaling axis as a promising therapeutic target. This study investigates the potential of SERPINB3 silencing as a novel therapeutic approach for HCC. The aim is to elucidate the molecular mechanisms by which SERPINB3 facilitates tumor growth and metastasis and to assess the effects of its suppression on critical oncogenic processes, including cell proliferation, invasion, and apoptosis. Human HA22T/VGH hepatoma cells were SERPINB3-specific siRNA and phosphate-buffered saline (PBS) as a mock control. Changes in gene expression were analyzed via quantitative real-time PCR (RT-qPCR), focusing on PAR2, c-Myc, and CEBPβ expression levels, and further validated through functional assays, including IncuCyte live-cell imaging for real-time proliferation analysis, and apoptosis resistance assays. Preliminary results indicate that silencing of SERPINB3 diminishes tumor cell proliferation, invasion, and migration, while enhancing apoptosis in HCC cells. Collectively, these findings emphasize the central role of SERPINB3 in hepatocarcinogenesis and support its potential as a molecular target for the development of innovative therapeutic strategies aimed at improving clinical outcomes for patients with hepatocellular carcinoma.