Inducing apoptosis and decreases cell proliferation in human breast cancer cells through miR-182-5p blockage caused by locked nucleic acid

Abstract

Background: MicroRNAs (miRNAs) are single strand and short non-coding RNAs involved in post-transcription expression of genes. MiRNAs exhibited a substantial role in numerous cellular processes including cell proliferation, differentiation, cell cycle, apoptosis, and cancer development by negative regulation of tumor suppressor or oncogenic genes. Breast cancer is one of the most common cancers in world. Several studies reveal that miR-182-5p is up-regulated in breast cancer. Methods: MiR-182-5p blockage was performed using locked nucleic acid (LNA) technology in human breast cancer cell line (MCF-7). After blockage, miR-182-5p expression, cell proliferation, apoptosis and necrosis were measured. MiR-182-5p expression was assessed by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) at 24, 48, and 72 hour after locked nucleic acid anti-miR-182-5p transfection. Moreover, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and annexin/propidium iodide staining were evaluated. Findings: MiR-182-5p expression decreased at 24, 48, and 72 hours after transfection in the locked nucleic acid group compared to control groups. Cell viability was statistically different between locked nucleic acid and control groups. In the locked nucleic acid group, due to miR-182-5p inhibition, apoptosis ratio increased more than the other groups. Similarly, necrosis ratio in the locked nucleic acid group increased more than the other groups. Conclusion: In this study, miR-182-5p blockage reduced cell viability in MCF-7 cells chiefly due to induction of apoptosis and necrosis. Our results can help translational medicine for investigation on antisense therapy in human breast cancer. © 2017, Isfahan University of Medical Sciences(IUMS). All rights reserved.