MiR-۲۰۵ expression is altered in Breast cancer

Background and Aim: Breast cancer is the most common malignancy among women. One of the genetic factors involved in cancer is microRNA. MicroRNAs are small noncoding RNAs that regulate various biological processes such as cellular differentiation, cellular metabolism and immune response. The molecules bind to the ۳'UTR of target mRNAs and block translation or, in less cases, lead to the mRNA degradation. MiRNAs can have both tumor suppressor and oncogenic roles, which are called OncomiR and Ts-miR. MiRs expression levels vary significantly between normal and cancer cells suggests that miRNA might be associated with cancer development and potentially could be used for cancer diagnosis or even treatment. MiR-۲۰۵ acts either as a tumor suppressor through inhibiting proliferation and invasion, or as an oncogene through facilitating tumor initiation and proliferation, depending on the specific tumor context and target genes. Loss of miR-۲۰۵-۵p is associated with enhanced metastatic potential in both model tumor systems and in human cancers, particularly of the breast. miR-۲۰۵-۵p is down regulated in breast cancer tissues and breast cancer cell lines compared with normal breast tissues and a non-tumorigenic breast epithelial cell line.The aim of this study was to evaluate miR-۲۰۵-۵p expression changes in Iranian women with breast cancer.Methods: In this case-control study, total RNA was extracted from tumor tissue and breast control samples using triazol reagent. Poly A tail was added to the extracted RNAs and complementary DNA (cDNA) was synthesized using anchored oligo-dT. Design of the miR-۲۰۵-۵p and housekeeping gene(U۶) primers was done by Oligo۷ software. Real Time-PCR was performed by an automated thermocycler and the expression changes of miR-۲۰۵ was studied. Statistical analysis of data was performed using software such as SPSS and Graph pad prism.Results: Our results indicated that miR-۲۰۵-۵p expression is lower in cancer samples than in healthy subjects. (p < ۰.۰۵)Conclusion: MiR-۲۰۵ is an important microRNA for inhibiton of proliferation and EMT and enhance apoptosis in breast cancer cells. We showed that miR-۲۰۵-۵p expression level has association with breast cancer .miR-۲۰۵-۵p may be used as a biomarker for cancer awareness as well as a target for cancer treatment.

Keywords:

miR-۲۰۵-۵p , Breast Cancer , gene expression , Real-Time PCR