MiR-217 Promotes Tumor Proliferation in Breast Cancer via Targeting DACH1

Abstract

licenses/by-nc-nd/3.0/). Reproduction is permitted for personal, noncommercial use, provided that the article is in whole, unmodified, and properly cited. Received: 2014.10.15; Accepted: 2014.12.05; Published: 2015.01.01 Objective: The expression of DACH1 was frequently lost in human breast cancer, which sig-nificantly correlated with poor prognosis. Herein, we aim to investigate its underlying mechanisms. Methods: The expression of miR-217 was detected by Taqman PCR. The mRNA and protein level of DACH1 were investigated by real time PCR and western blot. The dual-luciferase reporter system was used to determine the direct interaction between miR-217 and DACH1. A series of gain&loss of function assays were performed to measure the affects of miR-217 on tumor pro-liferation and cell cycle distribution. Results: Compared to that in normal breast samples, the expression of miR-217 was significantly upregulated in breast cancer tissues. High level of miR-217 was notably correlated with highly histological grade, the triple negative subtype and advanced tumor stage. Moreover, the expres-sion of miR-217 was negatively correlated with the expression of DACH1. The results of du-al-luciferase reporter assay demonstrated that miR-217 directly targets and inhibits the tran