Association between aldehyde dehydrogenase-2/cytochrome P450 2E1 genetic polymorphism and habit of alcohol drinking and the susceptibility of hepatocellular carcinoma

Objective To study the relationship between aldehyde dehydrogenase-2(ALDH2) and cytochrome P450 2E1(CYP2E1) gene polymorphism and alcohol drinking habit with the susceptibility of hepatocellular carcinoma(HCC).Methods 300 cases of HCC and 292 controls were genotyped for the ALDH2 and CYP2E1 polymorphisms by using polymerase chain reaction-restriction fragment length polymorphism( PCR-RFLP) method.Results The frequencies of ALDH2 and CYP2E1 variant genotypes in cases and controls were 50.3%,48.0% and 32.3%,32.9%,respectively.There was no significant difference of ALDH2 and CYP2E1 genotypes distribution between cases and controls (P0.05).The risk for liver cancer was 3.334 times higher in alcoholics (≥3 times drinking per week) with ALDH22 genotype than that that in cases carrying ALDH21 genotype while drinking less than 3 times per week (95%CI=1.746-6.406),and the risk for liver cancer was 1.803 times higher in alcoholics (≥3 times drinking per week) with CYP2E1c2 genotype than that in cases carrying CYP2E1c1 genotype while drinking less than 3 times per week (95%CI=0.974-3.336).Haplatype of the two genotypes increased liver cancer risk to 1.200 folds (95%CI=0.730-1.972),and interaction between drinking and genotypes increases risk of liver cancer to 1.816 folds (95%CI=0.985-3.348).Conclusion ALDH2 or CYP2E1 genotypes alone render no significant risk for HCC,while frequent alcoholic consumption together with ALDH2 or CYP2E1 variant genotypes are assocoated with risk of hepatocarcinogenesis,suggesting a gene-environment interaction in increasing risk for HCC among Guangxi residents.