Hsa-miR-1 suppresses breast cancer development by down-regulating K-ras and long non-coding RNA MALAT1.

MicroRNAs exert their functions by mainly regulating coding genes or long non-coding RNA expression. In the present study, we reported that hsa-miR-1 was down-regulated in breast cancer tissues. Restoration of miR-1 in breast cancer cells inhibited proliferation, motility and increased apoptosis in vitro. MiR-1 functioned as a tumor suppressor by targeting K-RAS and MALAT1. In addition, the effects of up-regulation of miR-1 were similar to that of silencing K-RAS and MALAT1 in breast cancer cells. In vivo study indicated that restoration of miR-1 inhibited tumor growth and metastasis. Patients with low miR-1 expression had poorer overall survival time than those with high miR-1 expression. Our findings emphasized the potential role of miR-1 as tumor suppressive miRNA in breast cancer.