The human liver circadian transcriptome and its carcinogenic perturbation by hepatitis C virus infection (RNA-Seq I)

Chronic liver disease and cancer are global health challenges. The role of the circadian clock (CC) as a regulator of physiology and disease is well established in animal models. However, in human liver the identity of circadian genes and their epigenetic regulation is unknown. Here, we unraveled the circadian transcriptome and epigenome of human hepatocytes using a human liver chimeric mouse model. We identified genes coding for transcription factors, chromatin modifiers, and critical enzymes which are expressed rhythmically in human hepatocytes, and which differ from the mouse liver circadian transcriptome. Moreover, we show that hepatitis C virus (HCV) infection, a major cause of liver disease and cancer world-wide, perturbs the human hepatocellular clock leading to an activation of pathways mediating steatosis, fibrosis and cancer. The HCV-disrupted rhythmic hepatic pathways remained deregulated in patients cured of HCV suggesting a major role in liver cancer development, and in the identification of therapeutic targets. Messenger RNA of paired biopsies from HCV-infected patients and the same patients after DAA-treatment was sequenced and analyzed.