Up-Regulation of Mir-105-5p Promotes The Development of Breast Cancer By Targeting AKT1 / GRB2 Genes In Patients With Breast Cancer

Abstract Objective: miR-105-5p either acts as an oncomiR or tumor suppressor that has been shown to have various expression levels in a wide range of diseases and targets RAC-alpha serine/threonine-protein kinase (AKT1) and Growth Factor Receptor-bound protein 2 (GRB2) genes. GRB2 is a signaling protein that takes part in various signaling pathways. Due to the fact that miRNAs by acting on target genes, and regulates the expression of them, so the aim of this study is to evaluate the expressions of miR-105-5P, AKT1, and GRB2 genes and the correlation between them in breast cancer (BC) tissue compared to normal-adjacent tissues (NATs) in women with breast cancer.Materials and methods: We utilized bioinformatics analysis to searching for target genes of miR-105-5p. Then, 35 BC and NATs tissues were taken. In this experimental study, quantitative Real-Time PCR was performed to evaluate miR-105-5P, AKT1 and GRB2 genes expression, and the correlation between them was evaluated. The relation between expression and features of clinicopathological was explored.Results: The miR-105-5p expression was increased significantly in BC tissues in comparison to NATs (P 0.05). The expression levels of AKT1 and GRB2 genes were decreased significantly in BC tissue in comparison to NATs (P 0.05). An inverse correlation was observed between miR-105-5p, AKT1 and GRB2 expression which was not significant (P>0.05). Also, a direct correlation was observed between GRB2 and AKT1 gene expression (P 0.05). Conclusion: Our findings revealed that increased expression levels of miR-105-5p in patients with breast cancer caused a decrease in the expression level of its target genes, AKT1 and GRB2, and subsequently lead to tumor progression and invasion of the tumor. miR-105-5p may serve as a promising target for BC therapy.