Genetic polymorphism of uridine-diphosphoglucuronosyl transferase 1A7 gene in chronic viral hepatitis and hepatocellular carcinoma

ABSTRACT

Hepatocellular Carcinoma [HCC] is the most common cause of primary liver neoplasm and the fourth most frequent type of cancer worldwide causing one million deaths per year. Genetic polymorphisms of UDP-glucuronosyltransferases [UGTs], which detoxifies endogenous and environmental carcinogen, have been reported to be associated with HCC. The present study aimed to elucidate the role of UGT1A7 SNP [622 T-C] in the pathogenesis of Hepatocellular Carcinoma [HCC] and whether this polymorphism is associated with elevated bilirubin level or not. This study was conducted on 22 patients with HCC, 25 patients with chronic viral hepatitis B and/ or C and 16 apparently healthy controls. All subjects underwent laboratory tests for Liver and Kidney functions, serological markers [HBV and HCV] and serum AFP as a tumor marker, Genomic DNA from the blood was analyzed for UGT1A7 polymorphism using PCR-RFLP. The prevalence of HCV infection was higher in HCC group compared to other groups. AFP-level significantly increased in HCC than in viral hepatitis and control [p<0.0005]. A statistically significant increase was found in the frequency of risky genotypes [TC, CC] in HCC group as compared to the protective genotype [TT] [P<0.01]. UGT1A7 T allele and C allele were designated as H [high activity] and L [low activity] alleles, respectively. A statistically significant increase was found in frequency of L allele in HCC group [54%] as compared to control group [25%] p=0.03. On the other hand, the H allele showed statistically significant decrease in HCC group [46%] compared to control group [75%] p=0.03. Increase in total bilirubin level in cases harboring UGT 1A7 Polymorphism compared to wild genotype [p<0.01] was observed demonstrating its role in the pathogenesis of hyperbilirubineamia. The UGT1A7 polymorphism was associated with elevated bilirubin level and may play a role in the pathogenesis of HCC