Association of genetic variants in tachykinins pathway genes with colorectal cancer risk

This study aims to explore the associations of polymorphisms in tachykinin, precursor 1 (TAC1), tachykinin receptor 1 (TACR1), and tachykinin receptor 2 (TACR2) genes and their interactions with the risk of colorectal cancer (CRC) among Chinese population. A population-based case-control study which included 394 cases and 393 cancer-free controls was carried out. A total of 19 tagSNPs in the three genes were chosen based on HapMap and NCBI datasets and genotyped by SNPshot assay. Multiple logistic regression models were applied to evaluate the associations of SNPs with CRC after adjustment for potential covariates. Furthermore, generalized multifactor dimensionality reduction (GMDR) method was used to test the interactive effect among three genes on CRC. Compared with those carrying rs3755457 CC/CT or rs12477554 TT/CT genotype, individuals carrying homozygous variants had higher risk of colorectal cancer (adjusted OR = 1.80, 95 % CI = 1.03-3.13, P = 0.039 for rs3755457; adjusted OR = 1.73, 95 % CI = 1.07-2.79, P = 0.024 for rs12477554). As for rs10198644, GG genotype was associated with a 1.72-fold (95 % CI = 0.37-0.88) decreased risk when compared with the common CC genotype. Moreover, the GMDR analysis indicated that the best interactive model included five polymorphisms: rs2072100 (TAC1), rs10198644 (TACR1), rs2193409 (TACR1), rs3771810 (TACR1), and rs4644560 (TACR2). Our study suggests that tachykinins pathway genes may participate in the development of CRC and the potential interactions among the three genes on CRC may exist, which has to be confirmed in future larger studies.