The effect and mechanism of atorvastatin regulating PI3K-Akt–mTOR pathway on radiosensitivity of hepatocellular carcinoma cells

Radiation therapy is an important method to treat liver cancer, but because of the strong DNA repair ability of liver cancer cells, even after receiving high doses of radiation still can not get satisfactory results. Atorvastatin (ATO) is a lipophilic and tissue-selective inhibitor of HMG-CoA reductase whose anticancer effects have been validated in various cells, but its effect on the radiation sensitivity of hepatocellular carcinoma cells remains unclear. Therefore, Therefore, this study explored the radiosensitivity of ATO and its possible mechanism by pretreating HepG2 with ATO and collecting HepG2 cells after irradiation. It was found that atorvastatin can not only affect the survival of liver cancer cells when used alone, but also enhance the radiation sensitivity of HepG2 cells. The study found that ATO significantly exacerbated the inhibitory effects of IR on the growth, proliferation, and migration of HepG2 cells. Measurement of ROS, SOD, GPx, and MDA levels indicated that ATO enhanced IR-induced oxidative stress, further promoted the decrease of Mitochondrial Membrane Potential, increased the rate of apoptosis in HepG2, upregulating pro-apoptotic proteins Bax and Cleaved-Caspase 3, and downregulating anti-apoptotic proteins Bcl-2. Western blot analysis showed that the PI3K-Akt-mTOR pathway was inhibited, leading to the activation of cytotoxic autophagy in HepG2 and an increase in the expression of the LC-3II protein. In summary, ATO, in combination with IR, enhances the oxidative stress response of HepG2 induced by IR, promotes autophagy by inhibiting the PI3K-Akt-mTOR pathway, and thereby potentially enhances the radiosensitivity of HepG2 as a pharmacological intervention.