Genetic polymorphisms of transforming growth factor-beta1 and its receptors and colorectal cancer susceptibility: a population-based case-control study in China.

The TGF-beta signaling pathway plays a very important role in the control of cell proliferation and differentiation that is involved in colorectal carcinogenesis. The associations between polymorphisms of TGF-beta1 and its receptors genes and the colorectal cancer risk were assessed in a population-based case-control study (206 cases and 838 controls). We could not observe any variant in the G-800A, codon25 and codon263 of TGF-beta1 and A-364G of TGFbetaR2 in Chinese population. However, the results revealed that -509CT and TT genotypes were significantly associated with decrease risk for colorectal cancer (adjusted OR=0.58, 95% CI 0.40-0.84 and adjusted OR=0.44, 95% CI 0.29-0.68, respectively). Moreover, the linkage disequilibrium analysis revealed that TGF-beta1 C-509T and codon10 polymorphisms were in strong linkage disequilibrium, and the -509C/+29C was associated with a significantly increased risk of colorectal cancer (OR=1.32, 95% CI=1.05-1.66). Our findings indicate that the distributions of polymorphisms in TGF-beta1 and its receptors genes vary greatly among different ethnic groups, and these polymorphisms might contribute to the colorectal cancer susceptibility.