RASSF1A and p16 promoter methylation and treatment response in chronic hepatitis C genotype 1b patients treated with pegylated interferon/ribavirin

Abstract

Prevention of chronic hepatitis C (CHC) and its complications is based on antiviral therapy and early detection of reliable molecular markers in persons under risk. We investigated whether the methylation status of RASSF1A and p16 genes, alone or in combination with host and viral factors, affects the response to therapy with pegylated interferon/ribavirin (PEGIFN/ RBV). Methylation-specific polymerase chain reaction (MSP) was used to determine the methylation status of the target promoter sequences of RASSF1A and p16 in circulating-free DNA from the peripheral blood of 49 patients with CHC genotype 1b. The methylation status of the examined genes did not affect the response to therapy. However, the simultaneous presence of either RASSF1A or p16 methylation and the CC genotype of IL28B was significantly related to a sustained virologic response (P=0.009 and P=0.032, respectively). After Bonferroni correction, only the result concerning the RASSF1A gene remained significant (P<0.0125). Methylation of RASSF1A was associated with the CC genotype of the IL28B gene (P=0.024) and a higher viral load (?400 000 IU/mL, P=0.009). Our results suggest that combined analysis of RASSF1A gene methylation and IL28B rs12979860 polymorphism could potentially help in the prediction of therapy response in CHC genotype 1b patients.