Icaritin with autophagy/mitophagy inhibitors synergistically enhances anticancer efficacy and apoptotic effects through PINK1/Parkin-mediated mitophagy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the deadliest malignancies worldwide and still a pressing clinical problem. Icaritin, a natural compound obtained from the Epimedium genus plant, has garnered significant attention as a potential therapeutic drug for HCC therapies. Mitophagy plays a crucial role in mitochondrial quality control through efficiently eliminating damaged mitochondria. However, the specific mechanisms of the interplay between mitophagy and apoptosis in HCC is still unclear. We aimed to explore the cross-talk between icaritin-induced mitophagy and apoptosis in HCC cells and investigate its potential mechanisms. Firstly, we confirmed that icaritin inhibits proliferation and migration while inducing mitochondrial damage and reactive oxygen species (ROS) production in HCC cells. Secondly, based on proteomics analysis, we discovered that icaritin inhibits the growth of tumor cells and disrupts their mitochondrial homeostasis through the regulation of both mitophagy and apoptosis. Thirdly, icaritin causes mitophagy mediated by PINK1-Parkin signaling via regulating feedforward loop. Furthermore, knockdown of PINK1/Parkin leads to inhibition of mitophagy, which promotes cell death induced by icaritin in HCC cells. Finally, autophagy/mitophagy inhibitors remarkably enhance icaritin-induced cell death and anticancer efficacy. Collectively, our findings reveal that icaritin suppresses growth, proliferation and migration of HCC cell through induction of mitophagy and apoptosis, while inhibition of mitophagy significantly increased the anti-cancer and pro-apoptotic effects of icaritin, indicating that targeting autophagy or mitophagy is a novel approach to overcome drug resistance and enhance anticancer therapies.