MiR-615 inhibited cell proliferation and cell cycle of human breast cancer cells by suppressing of AKT2 expression.

MicroRNAs (miRNAs) have emerged as important regulators that potentially play critical roles in various biological processes. Previous studies have shown that miR-615 regulates proliferation and apoptosis in many types of cancers. The biological function of this microRNA in breast cancer remains largely unexplored. In the present study, we found that miR-615 expression was markedly downregulated in breast cancer tissues and breast cancer cells. The enforced expression of miR-615 was able to inhibite the proliferation and anchorage-independent growth of breast cancer cells, while miR-615-in showed the opposite effect. Bioinformatics analysis further revealed AKT2, a putative tumor promoter as a potential target of miR-615. Ectopic expression of miR-615 led to downregulation of AKT2 protein, which resulted in the upregulation of p27 and p21 and the downregulation of cyclin D1. In sum, these results suggest that miR-615 represents a potential anti-onco-miR and participates in breast cancer carcinogenesis by suppressing AKT2 expression.