Glycyrrhizic acid attenuates sorafenib resistance by inducing ferroptosis via targeting mTOR signaling in hepatocellular carcinoma

Abstract

Background Hepatocellular carcinoma (HCC) is the most malignant cancer worldwide. Sorafenib (SRF) is a common therapeutic drug used for patients with advanced HCC. Nevertheless, drug resistance frequently occurs in patients treated with sorafenib. Glycyrrhizic acid (GRA) is a natural compound that is identified to exhibit anti-cancer effects. In this work, we aimed to investigate the effects of GRA on SRF-resistant HCC cells and the potential regulatory mechanisms. Methods We established SRF-resistant HCC cell lines and administrated GRA treatment. We performed CCK-8 and colony formation experiments to detect cell proliferation. The accumulation of lipid reactive oxygen species (ROS) and iron levels were measured to evaluate ferroptosis. The protein levels of ferroptosis suppressor glutathione peroxidase 4 (GPX4) and SLC7A11, and the activation of AKT and mTOR were measured with western blotting assay. Results GRA treatment notably suppressed the viability and proliferation of SRF-resistant HCC cells. SRF-resistant HCC cells exhibited repressed ferroptosis level activated AKT/mTOR cascade, and GRA treatment reversed these effects. Inhibition of ferroptosis and activation of mTOR reversed the anti-proliferation effects of GRA on SRF-resistant HCC cells. Conclusion Treatment with GRA could effectively reverse the SRF resistance of HCC cells via inducing ferroptosis and inactivating the AKT/mTOR cascade.