Association between G-2548A leptin gene polymorphism and breast cancer risk

Leptin is an adipokine made by fat cells and plays a key role in proliferation, cell survival, migration and immune response. Several studies have suggested that individuals with high serum leptin concentrations would increase the risk of breast cancer. G -2548A polymorphism in the leptin gene is located in the promoter region and is associated with the change of leptin serum level. In this study, the association between G -2548A polymorphism in leptin gene and breast cancer susceptibility was investigated. This case-control study was done on 374 Iranian women. This study was performed from March 2013 to February 2013. Blood samples from 203 women with breast cancer and 171 age (±5)- matched healthy women were collected. Breast cancer patients were selected from Namazi Hospital in Shiraz city. Genomic DNA was extracted from blood samples. The G -2548A polymorphism of leptin gene was determined using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Data analysis was performed by SPSS version 18. Logistic regression analysis was used for association of breast cancer susceptibility and G -2548A polymorphism of leptin gene. The A allele frequency was 60% in control group and 72% in breast cancer patients. There was a significant association between A allele in -2548 position of leptin gene and breast cancer susceptibility (OR: 1.8, 95% CI: 1.3-2.4, P<0.001). In the reces-sive effect of the A allele (comparison between AA vs. AG+GG), AA genotype in -2548 region of leptin promoter sequence was significantly increased the risk of breast cancer (OR=2.2, 95% CI: 1.5-3.4, P<0.001). It is concluded that A allele in the -2548 promoter region of leptin gene may act as a recessive allele and increase the breast cancer risk.