Functional genetic variants of TGF-β1 and risk of tobacco-related oral carcinoma in high-risk Asian Indians.

Transforming growth factor (TGF)-β1, the most abundant isoform of TGF-β have been implicated in various stages of carcinogenesis such as epithelial to mesenchymal transition, enhanced expression of metalloproteases, down-regulation of cellular adhesion molecule, increased tumor motility and angiogenesis as well as local and systemic immunosuppression leading to a more aggressive and metastatic behavior. We assessed the association of TGF-β1 functional genetic polymorphisms at codon 10 (869 T>C) and 25 (915 G>C) of exon 1 in 140 patients with tobacco-related oral squamous cell carcinoma (OSCC) and 120 normal subjects by PCR-RFLP. The frequency of 869 CC genotype and C allele were significantly higher in patients as compared to controls (P(c), 0.024 and 0.0004, respectively) while no significant difference was observed in the frequency of 915 CC genotype and C allele. In logistic regression analysis CC genotype (OR, 3.87; 95% CI, 1.78-8.41) and C allele (OR, 2.20; 95% CI 1.51-3.20) appeared as susceptible while TT genotype and T allele as protective. In addition C(869)-C(915) haplotype with OR of 2.48 at 95% CI, 1.51-4.06 significantly (P=0.0003) increased the risk of tobacco-related OSCC in Asian Indians.