Association of single nucleotide polymorphisms of adiponectin and leptin genes with breast cancer.

Single nucleotide polymorphisms (SNPs) in adiponectin gene [rs1501299 (+276G/T) and rs266729 (-11377C/G)] and one SNP of leptin gene [rs7799039 (-2548G/A)] are known to influence plasma levels of adiponectin and leptin respectively. Literature is scarce on the association of adiponectin gene polymorphism rs266729 with breast cancer. The present study was taken up to study these polymorphisms and their association with breast cancer. Ninety-three patients diagnosed with malignant breast cancer were included as cases along with 186 age matched healthy controls. Adiponectin +276G/T, -11377C/G and leptin -2548G/A polymorphism were studied using polymerase chain reaction (PCR) based restriction fragment length polymorphism (RFLP). Adipokine levels in blood were measured using enzyme linked immunosorbent assay. Adiponectin +276G/T and leptin -2548G/A showed a significant increased risk for breast cancer even after adjusting for confounding variables like present age, age at menarche, age at first child birth and age at menopause. In the subset analysis, based on menopausal state, stronger association was observed between SNP in adiponectin gene +276G/T with the breast cancer in post-menopausal women after adjusting for all other variables. No association was found with adiponectin -11377C/G. No association of the gene polymorphisms with adipokine levels was observed. Also, no significant association was seen for the effect of gene-environment interaction i.e. presence of polymorphism with obesity and menopausal state for any of the SNPs studied. Adiponectin +276G/T is strongly associated with breast cancer in postmenopausal women while leptin -2548G/A polymorphisms is significantly associated with breast cancer irrespective of the menopausal state in south Indian subjects.