Cabozantinib activates TFEB-mediated autophagy to exert anti-tumor effects in hepatocellular carcinoma.

Autophagy signaling plays a crucial yet complex role in hepatocellular carcinoma (HCC), influencing tumor progression and treatment response. Cabozantinib is an orally administered multi-kinase inhibitor used in the treatment of various advanced cancers, including renal cell carcinoma and HCC. However, its precise mechanisms of action in HCC require further elucidation. Our study first revealed elevated levels of phosphorylated TFEB (p-TFEB, Ser142) in human HCC tissues and cell lines, indicating impaired TFEB-mediated autophagic flux in hepatocellular carcinoma. Treatment with Cabozantinib induced dose-dependent cytotoxicity, oxidative stress (increased ROS and decreased GSH), and mitochondrial dysfunction (reduced Complex IV activity and ATP production). Furthermore, Cabozantinib promoted autophagy activation, as evidenced by increased autophagosome formation, elevated LC3-II/I conversion and Beclin1 expression, and decreased p62 levels. Mechanistically, Cabozantinib inhibited TFEB phosphorylation at Ser142 and enhanced its nuclear translocation. Critically, TFEB knockdown abolished Cabozantinib-induced autophagy, confirming that the pro-autophagic effects are TFEB-dependent. These findings demonstrate that Cabozantinib exerts its anti-tumor activity in HCC through activating TFEB-mediated autophagy pathway by inducing oxidative stress and mitochondrial damage.