effects of two common promoter polymorphisms of transforming growth factor-β1 on breast cancer risks in ahvaz, west south of iran

Background: transforming growth factor-β1 (tgf-β1) has a critical role in breast cancer initiation and progression. objectives: we have investigated the possible differences in two promoter polymorphisms (-509c/t and -800g/a) of tgf-β1 gene between breast cancer cases and controls. patients and methods: a total of 100 patients with confirmed breast cancer and 100 subjects without breast cancer was selected. two promoter polymorphisms (-509c/t and -800g/a) of tgf-β1 gene were genotyped using pcr-based restriction fragment length polymorphism (rflp) method. results: the allele frequencies were 63% for c allele and 37% for t allele of snp -509c/t and 66% for g allele and 34% for a allele of snp -800g/a. although no significant difference has observed between two groups, according to the genotype distribution, however, the tt genotype of -509 and aa genotype of -800 was significantly associated with breast cancer risk [odds ratio (or) = 2.409; 95% confidence interval (ci) = 1.087 - 5.337, p = 0.030; and or = 2.383; ci = 1.039 - 5.40, p = 0.040, respectively]. in addition, a multinomial logistic regression model shown, homozygous of -800 g/a (or = 0.570; 95% ci = 0.362 - 0.896, p = 0.015); and hdl-c (or = 0.935; 95% ci = 0.906 - 0.965, p < 0.001) were the selected variables associated with the presence of breast cancer. haplotype analysis has shown no significant association between tgf-β1 haplotypes and breast cancer risk. conclusions: our results indicated that among two promoter polymorphisms of the tgf-β1gene, -800g/a compared to -509c/t is more associated with breast cancer.