Apoptin Mediates Endogenous Mitophagy and Apoptosis by Regulating the Level of ROS in Hepatocellular Carcinoma

Background: Apoptin, as a tumor-specific pro-apoptotic protein, apoptin plays an important role in the field of anti-tumor, but its autophagy activation mechanism and the interaction between autophagy and apoptosis have not been accurately elucidated. Here, we studied the mechanism of apoptosis and autophagy induced by apoptin and the interaction between autophagy and apoptosis. Methods: Through crystal violet staining and CCK-8 assay, we analyzed the effect of apoptin in inhibiting liver cancer in vitro, and also analyzed the effect of inhibiting liver cancer in vivo by establishing a nude mouse tumor model. Flow cytometry and fluorescence staining were used to analyze the main types of apoptosis and autophagy induced by apoptin. Subsequently, the relationship between apoptosis and autophagy induced by apoptin was analyzed. Then, flow cytometry was used to analyze the effect of ROS on apoptosis and autophagy mediated by apoptin. Then, the affect of ROS on apoptosis and autophagy mediated by apoptin was analyzed. Finally, the key genes leading to autophagy were analyzed by silencing different genes.Results: The results showed that apoptin can significantly increase the apoptosis and autophagy of liver cancer cells, and apoptin can cause mitophagy through the increase of NIX protein. Apoptin can also significantly reduce the level of cellular ROS, which is related to the autophagy and apoptosis of liver cancer cells caused by apoptin. The change of ROS may be a key factor causing apoptosis and autophagy. Conclusion: The above results indicate that the increase of ROS level after apoptin treatment of liver cancer cells leads to the loss of mitochondrial transmembrane potential, which leads to endogenous apoptosis and mitophagy while recruiting NIX. Therefore, ROS may be a key factor connecting endogenous apoptosis and mitophagy induced by apoptin in liver cancer cells.