Atorvastatin Decreases HBx-Induced Phospho-Akt in Hepatocytes via P2X Receptors

Hepatocellular carcinoma (HCC) is rated as the fifth most common malignancy and third in cancer-related deaths worldwide. Statins, HMG-CoA reductase inhibitors, are potent cholesterol-lowering drugs, and recent epidemiologic evidence suggests that statins prevent aggressive HCC development. Previous experiments revealed that statins downregulate phosphorylated Akt (pAkt). Here, it is demonstrated that atorvastatin decreases nuclear pAkt levels in pancreatic and lung cancer cell lines within minutes, and this rapid effect is mediated by the purinergic P2X receptors. Akt is upregulated by hepatitis viruses and has oncogenic activity in HCC; therefore, we tested the possibility that the P2X-Akt pathway is important for the anticipated anticancer effects of statins in hepatocytes. Atorvastatin decreased hepatitis B virus X protein-and insulin-induced pAkt and pGsk3b (Ser9) levels. Furthermore, Akt-induced lipogenesis was counteracted by atorvastatin, and these statin-induced effects were dependent on P2X receptors. Statin also decreased proliferation and invasiveness of hepatocytes. These data provide mechanistic evidence for a P2X receptor-dependent signaling pathway by which statins decrease pAkt, its downstream phosphorylation target pGsk3b, and lipogenesis in hepatocytes. (C)2017 AACR.