-509C>T polymorphism in the TGF-β1 gene promoter is not associated with susceptibility to and progression of colorectal cancer in Chinese.

AIM

Colorectal cancer is common, accounting for nearly 10% of all cancers. Transforming growth factor-β1 (TGF-β1) is a pleiotropic cytokine that has been implicated in the pathogenesis of colorectal neoplasia. The most studied -509C>T polymorphism of TGF-β1 gene has been associated with various kinds of cancer. This study investigated the association between this genetic variant and the risk and/or progression of colorectal cancer.

METHOD

A case-control study was carried out of 150 colorectal cancer cases and 503 healthy controls. DNA was extracted from blood cell nuclear materials, and -509C>T polymorphism in the TGF-β1 gene promoter was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Colorectal cancer tissues (n = 70) were obtained from the studied cases for measurement of TGF-β1 mRNA expression levels. We also assessed the plasma TGF-β1 levels of cases (n = 88) and healthy subjects (n = 120).

RESULTS

The TGF-β1 producer genotype, -509TT, was not associated with an increased risk of colorectal cancer compared with other genotypes. Colorectal cancer patients especially those with a more aggressive disease behaviour were more frequently associated with C allele.

CONCLUSION

The results suggest that TGF-β1 -509C>T polymorphism is not associated with either an increased risk or progression of colorectal cancer.