CYP7A1 (-204 A > C; rs3808607 and-469 T > C; rs3824260) promoter polymorphisms and risk of gallbladder cancer in North Indian population

Cholesterol 7-alpha hydroxylase (CYP7A1), which is a rate-limiting enzyme for cholesterol catabolism and bile acid synthesis, may affect cholesterol homeostasis and result in gallstone formation that is a major risk factor for gallbladder cancer (GBC) pathogenesis. Genetic variations in CYP7A1 may influence its expression and thus may affect the risk of gallstone disease and GBC. We aimed to study the association of 2 promoter polymorphisms of CYP7A1 (-204 A>C [rs3808607] and 469 T>C [rs3824260]) in gallstone and GBC susceptibility in North Indian population. The study included 185 GBC patients, 195 symptomatic gallstone patients, and 200 healthy controls. Genotyping for both polymorphisms was done by polymerasc chain reaction restriction fragment length polymorphism method. Although the CC genotype of CYP7A1 204 A>C was not significantly associated with gallstone disease (P =.083, odds ratio [OR] = 1.69, 95% confidence interval [CI] = 0.9-3.0), it was conferring higher risk for GBC (P =.018, OR = 2.05, 95% Cl = 1.1-3.7). However, CYP7A1 -469 T>C was not associated with gallstone disease and GBC risk in our population. After subgroup stratifications on the basis of sex and gallstone status, CC genotype and variant allele of CYPA1 -204 A>C imparted higher risk for GBC in women (P =.003, OR = 3.30, 95% Cl = 1.5-7.2) 1 and. patients without gallstones (P =.045, OR = 1.91, 95% Cl = 1.2-3.6). Haplotype analysis of the 2 polymorphisms showed that C, T (P =.045, OR = 1.84, 95% Cl = 1.0-3.3) and C,C (P =.0001, OR = 3.10, 95% Cl = 1.6-6.0) haplotypes had elevated risk of GBC predisposition. CYP7A1 469 T>C is not associated with gallstone disease or GBC risk. Although CYP7A1 -204 A>C might play a modest role in gallstone susceptibility, it is an independent risk factor for GBC in North Indian population. Underlying mechanism for GBC susceptibility by CYP7A1 (-204 A>C and 469 T>C) haplotypc appears to be independent of gallstone pathway and is believed to involve genotoxicity resulting from subnormal bile acid production. (c) 2010 Elsevier Inc. All rights reserved.