The genotype of the transporter associated with antigen processing gene affects susceptibility to colorectal cancer in Japanese.

ABSTRACT

OBJECTIVE: Although colorectal cancer (CRC) is one of the most frequent malignancies in Japan, the associated genetic factors remain to be elucidated. Functional loss of the transporter associated with antigen processing (TAP) 1 gene induces carcinogenesis. We investigated whether single nucleotide polymorphisms (SNPs) in the TAP1 gene (rs735883) are associated with susceptibility to CRC in a Japanese population. METHODS: The study participants were 143 cases and 243 clinical controls. After extracting DNA from their peripheral blood cells, genotyping was conducted by the polymerase chain reaction-restriction fragment length polymorphism method. RESULTS: Participants with a mutated allele had an increased risk for CRC. The adjusted odds ratios for the C/T, T/T, and the mutation type (C/T + T/T) compared to that of wild type (C/C) were 2.27 [95 % confidence interval (CI), 1.43-3.67], 1.95 (95 % CI, 0.88-4.30), and 2.22 (95 % CI, 1.42-3.55), respectively. Furthermore, a significant trend in the rate of cases was observed with an increasing number of mutated alleles (P for trend = 0.0068). CONCLUSIONS: The genotype of the TAP1 gene is associated with susceptibility to CRC.