CCL22 16C/A Genetic Variation is not Associated with Breast Carcinoma in Southern Iranian Population

Background: CCL22/MDC is a CC chemokine with a critical role in regulation of the immune balance in physiological condition. CCL22/CCR-4 ligation has been documented to participate in the migration of regulatory T (Treg) cells and Th2 lymphocytes to the site of breast tumors; circumstances that are known to be associated with poor prognosis. Objective: To investigate the association of a single nucleotide polymorphism (SNP) in CCL22 gene; 16C/A (rs4359426; Asp2Ala), with susceptibility to breast cancer in a sample of Iranian population. Methods: 161 patients with pathologically confirmed breast carcinoma (mean age 49.3 ± 11.5 yrs) and 178 agematched healthy women (mean age: 49.3 ± 12.9 yrs) were studied. CCL22 genotypes were investigated by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. Data was verified by direct automated sequencing. Arlequin analysis showed no deviation from Hardy-Weinberg equilibrium. Results: The most frequent genotype in both patient and control groups was wild type CC genotype with frequency of 146 out of 161 (90.7%) among patients and 153 out of 178 (86.0%) in control group (p=0.24). The frequency of CA genotype was 15 (9.3%) and 23 (12.9%) in patients and controls, respectively (p=0.38). No AA genotype was observed among patients but this genotype was observed with the frequency of 2 out of 178 (1.1%) in control subjects. The minor allele frequency (MAF) was 0.07 in the population. Conclusion: No correlation was found between the investigated genotypes and clinicopathological characteristics of the patients. Conclusively, results of this investigation do not support the association of 16C/A SNP (rs4359426; Asp2Ala) in CCL22 gene with susceptibility to, and progression of, breast cancer in Iranian population.