miR-144 functions as a tumor suppressor in breast cancer through inhibiting ZEB1/2-mediated epithelial mesenchymal transition process

Breast cancer is the most common cancer in women worldwide. Local invasion, metastasis, and chemotherapy resistance are the obstacles for treatment of breast cancer. In this study, we aim to investigate the role of miR-144 in breast cancer. We demonstrate that the expression of miR-144 is downregulated in breast cancer and cell lines, and lower miR-144 expression is associated with poor differentiation, higher clinical stage, and lymph node metastasis in patients with breast cancer. The rescue of miR-144 expression is able to inhibit the cell proliferation and the ability of cell migration and invasion. In addition, we show that miR-144 can directly target at 3'-untranslation region of zinc finger E-box-binding homeobox 1 and 2, that is, ZEB1 and ZEB2, and regulate their expression at transcriptional and translational levels. Moreover, we also demonstrate that ectopic expression of miR-144 can inhibit the process of epithelial mesenchymal transition in MCF-7 and MDA-MB-231 cells. Thus, we here demonstrate that miR-144 functions as a tumor suppressor in breast cancer at least partly through inhibiting ZEB1/2-mediated epithelial mesenchymal transition process. Our findings indicate that the miR-144-ZEB1/2 signaling could represent a promising therapeutic target for breast cancer treatment.