MiR-186 Inhibits Proliferation, Migration, and Epithelial-mesenchymal Transition in Breast Cancer Cells by Targeting Twist1

Objective: Breast cancer (BC) is the most prevalent malignancy in women worldwide. Our study aimed to investigate the expression and biological effect of miR-186 in BC.

Methods: Expression of miR-186 was determined by quantitative reverse transcription PCR. Kaplan-Meier curves were calculated for the survival data analysis. Functional assays were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and wound healing assay. Protein expression was analyzed by Western blot.

Results: miR-186 was downregulated in BC tissues and cells. Downregulation of miR-186 was associated with tumor metastasis and a poor overall survival in patients with BC. Overexpression of miR-186 inhibited BC cells proliferation, migration, and epithelial-mesenchymal transition process; while suppression of miR-186 exhibited an opposite effects on BC cells. In addition, Twist1 was identified as a direct target of miR-186 in BC and restoration of Twist1 attenuated the biological effect of miR-186 on BC cells.

Conclusion: Our findings suggest that miR-186 functions as a tumor suppressor by targeting Twist1 in BC. miR-186 may serve as a novel biomarker in BC diagnosis or a new therapeutic target in BC treatment.