title: Hypermethylated levels of E-cadherin promoter in Huh-7 cells expressing the HCV core protein.
abstract: OBJECTIVE
  The mechanisms of hepatocarcinogenesis induced by hepatitis C virus remain unclear. Our aim was to investigate the effect of the HCV core protein on the promoter methylation status of selected genes potentially involved in the hepatocellular carcinoma (HCC).
  
  
  METHODS
  We evaluated the promoter methylation levels of the E-cadherin (CDH1), the glutathione S-transferase p1 (GSTP1), adenomatosis polyposis coli (APC), tissue inhibitor of metalloproteinase 3 (TIMP3), catenin (cadherin-associated protein) beta 1 (CNNTB1) genes by a quantitative methylation-specific polymerase chain reaction (QMSP) in the in vitro model of Huh-7 cells expressing the HCV core protein of genotype 1b.
  
  
  RESULTS
  We found that CDH1 promoter was hypermethylated in genotype 1b HCV core protein-positive cells as compared to control cells expressing the GFP protein alone (HCV core 1b vs GFP p=0.00; HCV core 1b vs Huh-7 p=0.03). This resulted in reduced levels of CDH1 protein as evaluated by immunoblot and by immunofluorescence. On the other hand no significant changes were observed for the other genes investigated. Furthermore, we present evidence that genotype 1b HCV core protein expression induces SIRT1 upregulation and that treatment with SIRT1 inhibitor sirtinol decreases the methylation levels of CDH1 promoter (1b+sirtinol vs 1b p=0.05; 1b+sirtinol vs GFP+sirtinol p=NS) resulting in 1.7-fold increased CDH1 mRNA expression (1b+sirtinol vs 1b p=0.05).
  
  
  CONCLUSIONS
  Our findings suggest that HCV core protein could play a role in HCC at least in part by altering the methylation status of CDH1 promoter. These findings could also suggest a novel therapeutic approach for HCC.
authors.affiliation: Gastroenterology Unit, IRCCS Casa Sollievo della Sofferenza Hospital, viale dei Cappuccini n.1, 71013 San Giovanni Rotondo (FG), Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Ripoli
authors.forename: Raffaela
authors.initials: R
authors.lastname: Barbano
authors.forename: Teresa
authors.initials: T
authors.lastname: Balsamo
authors.forename: Claudia
authors.initials: C
authors.lastname: Piccoli
authors.forename: Virgilio
authors.initials: V
authors.lastname: Brunetti
authors.forename: Michelina
authors.initials: M
authors.lastname: Coco
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Mazzoccoli
authors.forename: Manlio
authors.initials: M
authors.lastname: Vinciguerra
authors.forename: Valerio
authors.initials: V
authors.lastname: Pazienza
mesh_terms: D015820:Cadherins / Q000235:genetics*; D002460:Cell Line; D019175:DNA Methylation; D015870:Gene Expression; D016174:Hepacivirus / Q000472:pathogenicity*; D022781:Hepatocytes / Q000821:virology*; D006801:Humans; D011401:Promoter Regions, Genetic; D014758:Viral Core Proteins / Q000096:biosynthesis*
chemical_list: D015820:Cadherins; D014758:Viral Core Proteins; C069130:nucleocapsid protein, Hepatitis C virus