MiR-27b directly targets Rab3D to inhibit the malignant phenotype in colorectal cancer

MiRNAs, as oncogenes or as anti-oncogenes, play critically regulated roles in the initiation and progression of colorectal cancer at posttranscriptional level. However, the underlying functions of miR-27b in colorectal cancer remain largely unexplored. Here, we demonstrated miR-27b is significantly down-regulated in colorectal cancer tissues, and decreased miR-27b expression was closely associated with shorter overall survival of patients with colorectal cancer. By gain- and loss-of-function studies, we showed miR-27b remarkably suppressed cell proliferation and invasion of colorectal cancer. Furthermore, luciferase reporter assay identified Rab3D was the direct functional target of miR-27b. And Rab3D partly reversed the suppression of cell proliferation and invasion caused by miR-27b mimics. Finally, the animal experiment showed miR-27b plays a crucial role on colorectal cancer progression by targeting Rab3D. Taken together, our study implied miR-27b inhibits cell growth and invasion by targeting Rab3D, and miR-27b is a potential biomarker for prognosis and therapeutic target in colorectal cancer.