Relationship between genetic polymorphism of promoter region let-7 and genetic susceptibility to hepatocellular carcinoma

Abstract

The purpose of this study was to discuss the relationship between genetic polymorphism of promoter region let-7 and genetic susceptibility to hepatocellular carcinoma (HCC) in Chinese population. In this case-control study, 1300 cases of HBV positive patients were recruited in case group and another 1344 cases of persistent chronic HBV carriers were selected as control. 5 ml of blood sample was collected from each subject, from which the DNA was extracted; and rs10877887 and rs13293512 in promoter region let-7 were selected as the study sites. The polymorphism was detected by TaqMan allelic discrimination assay and the OR value (95%CI) was evaluated by Logistic Regression Method to analyze the relationship between susceptibility to HCC and different genotypes. The frequencies of genotype TT, CT and CC in site rs10877887 were 43.0% (542/1261), 44.7% (564/1261) and 12.3% (155/1261) respectively in case group; while separately 44.0% (581/1319), 44.4% (585/1319) and 11.6% (153/1319)in control group. The frequencies of genotype TT, CT and CC in site rs13293512 were 32.0% (406/1270), 48.1% (611/1270) and 19.9% (253/1270) respectively in case group; while separately 33.1% (427/1291), 49.4% (638/1291) and 17.5% (226/1291) in control group. The results of multifactor logistic regression analysis showed no statistical significance in the relationship between different genotype TT, mutated genotype C in site rs10877887 and susceptibility to HCC (CC + CT vs TT, adjusted OR = 1.05, 95%CI: 0.90 - 1.23); and either no statistical significance in the relationship between different genotype TT, mutated genotype C in site rs13293512 and susceptibility to HCC (CC + CT vs TT, adjusted OR = 1.06, 95%CI: 0.89 - 1.25). The united-analysis of the two sites showed the frequencies of 0, 1, 2 and 3-4 mutated-genotype C were 13.3% (164/1235), 36.2% (447/1235), 33.0% (408/1235) and 17.5% (216/1235) respectively in case group; and separately 14.2% (181/1269), 37.0% (469/1269), 33.1% (420/1269) and 15.7% (199/1269) in control group. The susceptibility to HCC in 1,2,3-4 mutated-genotype C carriers were 1.05 (0.81 - 1.34), 1.07 (0.83 - 1.38) and 1.22 (0.91 - 1.62) times of the non-mutated genotype subjects; but there was no statistical significance (Wald χ(2) = 1.79, P = 0.181). The polymorphism of study sites rs10877887 and rs13293512 may not be the biomarker of susceptibility to HCC in Chinese.