Association between multidrug resistance 1 gene polymorphisms and genetic susceptibility to sporadic colorectal adenocarcinoma

Abstract

Objective To investigate the association between genetic polymorphism in exon 26 C3435T and exon 21 G2677T/A of the multidrug resistance 1 (MDR1) gene and the sporadic colorectal adenocarcinoma.Methods A total of 123 patients with colorectal adenocarcinoma and 86 healthy subjects as controls were included.Snapshot SNP typing was used to determine the allele and genotype frequencies of MDR1 C3435T,and G2677T/A.Results There was no significant difference in the distribution of MDR1 C3435T and G2677T/A alleles and genotypes frequencies between control group and case group.When stratified by clinicopathological features such as lesion distribution,differentiation degree and Duke' s stage in the patients with colorectal adenocarcinoma,the statistically significant differences were found in the frequency of C3435T genotype between patients with colon adenocarcinoma (CC 22.2％,CT 63.4％,and TT 14.8 ％) and rectal adenocarcinoma (CC 50.7％,CT 31.9％,and TT 17.4％) (P ＜ 0.01).The frequency of 3435T allele was decreased significantly in patiens with rectal adenocarcinoma (33.3％) as compared with colon adenocarcinoma (46.3％,P ＜0.05).And the frequency of 2677GT genotype was decreased significantly in patients with moderately-differentiated (26.9％) as compared with well-differentiated (46.4％) and poorly-differentiated (47.1％,P ＜ 0.05).Furthermore,the frequency of 2677GT genotype was increased significantly in patients with colon adenocarcinoma (46.3％) as compared with rectal adenocarcinoma (24.6％,P ＜ 0.05),and the frequency of 2677G allele was decreased significantly in patiens with poorly differentiated adenocarcinoma (3.7％) as compared with moderately-differentiated (28.5％) and well-differentiated adenocarcinoma (11.0％,P ＜ 0.05).Conclusion MDR1 C3435T and G2677T/A polymorphisms were found to be not associated with colorectal adenocarcinoma. Key words: Colorectal carcinoma; Multidrug resistance gene; Polymorphism