HLA-G 14-bp Insertion /Deletion (In/Del) Polymorphism in Breast Cancer Iraqi Arabian women

Abstract

Background: Breast cancer is a group of diseases in which the breast cells change and divide uncontrolled, typically resulting in a lump or mass. Human leukocyte antigen -G (HLA-G) gene is a none -classic major histocompatibility complex (MHC) class I molecule that is highly expressed in cancer pathologies and is one of the strategies used by tumor cells to escape immune surveillance. A14-bp insertion/deletion (In/Del) polymorphism in exon 8 of the 3` untranslated region (3`-UTR ) of the HLA-G gene has been suggested to be associated with HLA-G mRNA stability and the expression of HLA-G. The present study aimed to the genotyping of the 14-bp In/Del in the HLA-G gene and its relation with clinical characteristics in Iraqi Arab breast cancer women.Materials and methods : Sixty women affected with breast cancer were enrolled in this study, in addition to 40 age -sex and ethnically matched healthy individuals participated as the control group, genotyping was performed using conventional polymerase chain reaction (PCR) and electrophoresis assays with specific primers. Results:The results of current study revealed that the prevalence of HLA-G 14-bp homozygous insertion genotype (ins/ins) was higher in breast cancer patients (26.7%) , while in control group (12.5%) ( OR = 2.55, 95%CI=0.86-7.54 , P= 0.088). The frequency of the ins allele was higher in breast cancer patients (51.7%), while in the control group (40 %), but no significant differences were observed in the distribution of alleles and genotypes between the patients and control groups. Moreover, we evaluated the possible correlation of the HLA-G 14-bp In/Del genotypes and clinical characteristics of the patients, but no statistically significant correlation was found, except for histologic grade and tumor type under (P≤ 0.05). Conclusion:The result revealed the most frequencies polymorphism is the homozygous insertion genotype (ins/ins) of the HLA-G 14-bp and its allele in Iraqi Arabian breast cancer women. No significant association between this polymorphic site and breast cancer although the data revealed a significant relation in genotype and allele frequency of 14-bp polymorphism between grade I, II, and III of breast cancer patients Larger case-control study including other polymorphic sites of the HLA-G gene is necessary to substantiate the importance of HLA-G polymorphisms and linkage disequilibrium in breast cancer risk.