Killer cell immunoglobulin-like receptor genes in patients with breast cancer

Killer cell immunoglobulin-like receptors (KIRs) contribute to the pathogenesis of diverse kind of diseases. Previous studies have shown associations between KIR genes, their ligands and either protection or susceptibility to leukemias or virally associated solid tumors. However, the possible roles of KIR gene polymorphisms in the development of breast cancer remain largely unknown. To investigate the association of KIR gene polymorphisms with breast cancer, we carried out the present study on 33 breast cancer patients and 77 healthy controls by means of sequence-specific oligonucleotide probes analysis, and then all data were statistically analyzed by Fisher exact test. Our results showed that the frame genes KIR2DL4, 3DL2, 3DL3, and 3DP1 were found in all patients and all controls. The rate of activating KIR2DS1 was much higher in patients with breast cancer than that in healthy controls (P = 0.032) while the allelic types of activating 2DS4 (2DS4*003/4/6/7) were lower in patients with breast cancer compared with healthy controls (P = 0.028). Additionally, there was a statistically significant negative correlation between 2DL1 genes and breast cancer development (P = 0.025). In conclusion, this study suggests that the activating KIR2DS1 may trigger breast cancer development, while 2DL1 gene and 2DS4*003/4/6/7 alleles are possibly protectors for breast cancer.