Association between polymorphisms of interleukin-6 gene promoter and breast cancer

Objective: To study possible association between three single nucleotide polymorphisms (-597G/A, -572C/G and -174G/C) of interleukin-6 (IL-6) gene promoter and breast cancer.

Methods: Genomic DNA was isolated from the venous blood leukocytes from 176 unrelated patients with breast cancer and 200 healthy unrelated females (control group). Polymorphisms of -597G/A, -572C/G and -174G/C, were genotyped by PCR-restriction fragment length polymorphisms (PCR-RFLP). SPSS 11.5 software was employed for statistical analysis and the association of IL-6 polymorphisms with breast cancer was evaluated by x(2); test.

Results: There was significant differences in both allele and genotype frequencies of -572C/G in case group compared with control group. The allele G of -572C/G was significantly higher in cancer patients than the controls(x(2);=15.438, P<0.01).

Conclusions: There is an association between -572C/G polymorphism and breast cancer risk. The females with G allele of -572C/G are susceptible to breast cancer compared with non-carrying females.