LicA induces autophagy through ULK1/Atg13 and ROS pathway in human hepatocellular carcinoma cells

Chemotherapy is the best choice for the vast majority of hepatocellular carcinoma patients at late stage, but few effective chemotherapy drugs are available in clinic. Licochalcone A (LicA) is a new chemotherapy drug inducing apoptosis as Bcl-2 inhibitor, but few studies report on LicA-induced autophagy. This study investigated the phenomenon and mechanisms of LicA-induced autophagy looking for a targeted combination drug. Human hepatocellular carcinoma cells (HCCs) were treated with LicA, to detect markers of autophagy and to investigate the mechanisms. In order to investigate the role of reactive oxygen species (ROS) in LicA-induced autophagy, ROS, glutathione (GSH) and O(2)(−) were measured in LicA treated HCCs, and antioxidant N-Acetyl-L-cysteine (NAC) was cotreated with LicA in HCCs, then mechanisms of ROS-induced autophagy was investigated in LicA or LicA combined with NAC treated HCCs. Finally, the LicA-induced apoptosis was detected in LicA combined with NAC treated HCCs. We first report that LicA can induce autophagy through ULK1/Atg13 and ROS pathway in HCCs, suppression of LicA-induced ROS through antioxidant NAC can enhance LicA-induced apoptosis, promoting the function of LicA killing HCCs. LicA can activate the ULK1/Atg13 complex which is upstream of autophagy, additionally, LicA also can promote ROS generation, ROS trigger the expression level of TSC1/2 complex, PRAS40, CTMP, PP2A, PDK1 and Rubicon change, these molecules are upstream of autophagy. In conclusion, LicA can induce autophagy through ULK1/Atg13 and ROS pathway in HCCs, LicA combined with NAC can enhance LicA-induced apoptosis. Our results may provide a novel design for clinical hepatocellular carcinoma therapy trials.