microRNA-139-5p exerts tumor suppressor function by targeting NOTCH1 in colorectal cancer

miR-139-5p was identified to be significantly down-regulated in colon tumor tissues by miRNA array. We aimed to clarify its biological function, molecular mechanisms and direct target gene in colorectal cancer (CRC). The biological function of miR-139-5p was examined by cell growth, cell cycle and apoptosis analysis in vitro and in vivo. miR-139-5p target gene and signaling pathway was identified by luciferase activity assay and western blot. miR-139-5p was significantly down-regulated in primary tumor tissues (P