Allele frequencies of the snps within microrna genes in healthy and patient populations with breast cancer

Due to their potentially functional significance, genetic variants within microRNA genes have been recognized as candidates for cancer-related genetic biomarkers. Accumulating evidence has indicatedthat single nucleotide polymorphisms (SNPs) in miRNA precursors may have an effect on miRNA expression levels. Studies have shown that miR-323b has a tumor suppressor role by reducing in thetissues and serum of the affected individuals and miR-182 has an oncogenic role in the cancer. So far, no study on rs56103835 and rs4541843, polymorphism in precursor of miR-323b and flanking regionof miR-182 respectively, in breast cancer versus healthy population. In this study, the prevalence of theses SNPs in the Iranian population has been investigated. In this study, 161 patients and 162 healthypeople as control group were examined who were homogenized based on age and gender. The genotype of individuals for the polymorphism was determined by the PCR_RFLP method. The prevalence of theses SNPs in the Iranian population has been calculated and it was compared with the information reported at the dbSNP database.An important G to A transition SNP in downstream of miR-182(rs4541843) and T to C transition in pre miR-323b(rs56103835) were identified. Based on the dbSNP database, the frequency of minor allele A in rs4541843 and C in rs56103835 is 28% and 29% respectively. While in this study, the frequency of allele A in rs4541843 in the healthy population was 51% and in the population of patients was 45%. Moreover, the frequency of allele C in rs56103835 in two healthy and healthy populations, 20% and 25% were calculated respectively. Variants within these miRNA genes and its flanking regions may interfering with the processing of these pre-miRNA andaltered the expression of target genes such as BRCA2 for miR-323b and FBXW7 for miR-182 And due to the difference in the allelic abundance of these SNPs in two healthy and mature populations, thesechanges may affect the onset of disease or progression of the disease.

Keywords:

Breast Cancer , Cancer Diagnosis , Gene and Cancer , Cancer Risks , Cancer Genetics