title: Epigenetic signatures of alcohol abuse and hepatitis infection during human hepatocarcinogenesis.
abstract: Hepatocellular carcinoma (HCC) is the second most common cause of cancer deaths worldwide. Deregulated DNA methylation landscapes are ubiquitous in human cancers. Interpretation of epigenetic aberrations in HCC is confounded by multiple etiologic drivers and underlying cirrhosis. We globally profiled the DNA methylome of 34 normal and 122 liver disease tissues arising in settings of hepatitis B (HBV) or C (HCV) viral infection, alcoholism (EtOH), and other causes to examine how these environmental agents impact DNA methylation in a manner that contributes to liver disease. Our results demonstrate that each 'exposure' leaves unique and overlapping signatures on the methylome. CpGs aberrantly methylated in cirrhosis-HCV and conserved in HCC were enriched for cancer driver genes, suggesting a pathogenic role for HCV-induced methylation changes. Additionally, large genomic regions displaying stepwise hypermethylation or hypomethylation during disease progression were identified. HCC-HCV/EtOH methylomes overlap highly with cryptogenic HCC, suggesting shared epigenetically deregulated pathways for hepatocarcinogenesis. Finally, overlapping methylation abnormalities between primary and cultured tumors unveil conserved epigenetic signatures in HCC. Taken together, this study reveals profound epigenome deregulation in HCC beginning during cirrhosis and influenced by common environmental agents. These results lay the foundation for defining epigenetic drivers and clinically useful methylation markers for HCC.
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Hlady
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, USA. Cancer Center, Georgia Regents University, Augusta, GA, USA.
authors.forename: Rochelle L
authors.initials: RL
authors.lastname: Tiedemann
authors.affiliation: Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: William
authors.initials: W
authors.lastname: Puszyk
authors.affiliation: Department of Surgery, University of Florida, Gainesville, FL, USA.
authors.forename: Ivan
authors.initials: I
authors.lastname: Zendejas
authors.affiliation: Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, USA.
authors.forename: Lewis R
authors.initials: LR
authors.lastname: Roberts
authors.affiliation: Cancer Center, Georgia Regents University, Augusta, GA, USA.
authors.forename: Jeong-Hyeon
authors.initials: JH
authors.lastname: Choi
authors.affiliation: Department of Pathology, Immunology and Laboratory Medicine, University of Florida, Gainesville, FL, USA.
authors.forename: Chen
authors.initials: C
authors.lastname: Liu
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, USA.
authors.forename: Keith D
authors.initials: KD
authors.lastname: Robertson
mesh_terms: D000437:Alcoholism / Q000175:diagnosis / Q000235:genetics*; D063646:Carcinogenesis; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D045744:Cell Line, Tumor; D019175:DNA Methylation / Q000235:genetics*; D044127:Epigenesis, Genetic; D005260:Female; D006505:Hepatitis / Q000235:genetics*; D006509:Hepatitis B / Q000175:diagnosis / Q000235:genetics; D006526:Hepatitis C / Q000175:diagnosis / Q000235:genetics; D006801:Humans; D008099:Liver; D008103:Liver Cirrhosis / Q000235:genetics; D008113:Liver Neoplasms / Q000235:genetics*; D008297:Male