Delta 32 mutation in CCR5 gene and its association with breast cancer.
17 Background: Chemokine C-C motif receptor type 5 (CCR5) is a chemokine receptor protein, which is present on the cell surface. Its potential role in cancer progression and metastasis has been implicated. Deletion mutation of 32 base pairs (bp) in the open reading frame of the CCR5 gene (CCR5Δ32) may lead to the malformation of the protein. This study aimed to examine the role of CCR5Δ32 mutation and its association with breast cancer. Methods: Blood samples of 500 breast cancer patients were included in the study. The samples were compared with age and sex matched healthy controls. Mutation of CCR5Δ32 was analyzed by sequence specific primers by polymerase chain reaction (PCR). They were examined on agarose gel electrophoresis. Statistical analyses were performed using software SPSS 17.0 (Chicago, IL., USA). The genotypic frequencies of patients and controls were tested by applying the chi‐square test. Results: Two types of CCR5 allelic mutations were found in the breast cancer samples. The mutation was of a 32 (bp) DNA fragment. Homozygous insertion (I/I) and heterozygous deletion (I/D) was found in the open reading frame of the regulatory region of the gene. The chi square analyses showed significant positive association between I/I and I/D allele in breast can patients with CCR5 delta 32 mutation (χ2 15.07, p < 0.01). Conclusions: This deletion in the promoter region of the CCR5 gene produces a non-functional receptor which may increase inflammation, leading to the enhanced progression of tumor.