MiR-511-5p functions as a tumor suppressor and a predictive of prognosis in colorectal cancer by directly targeting GPR116.

OBJECTIVE: Previous studies have revealed that miR-511-5p was abnormally expressed in several cancers. In this study, we aimed to develop a study on the expression patterns, clinical value, and functional roles of miR-511-5p in colorectal cancer (CRC). PATIENTS AND METHODS: MiR-511-5p and GPR116 were analyzed in CRC cell lines and tumor specimens by Real-time PCR. The clinical correlations between miR-511-5p expression and the clinicopathologic factors and prognosis were analyzed. The potential influences of miR-511-5p expression on CRC cell growth, apoptosis, and invasion abilities were analyzed by MTT, clonogenic assay, flow cytometry and transwell assay, respectively. Luciferase assays, qRT-PCR and Western blotting were carried out for the discovery of the target gene of miR-511-5p. RESULTS: MiR-511-5p was dramatically decreased in CRC samples and cells. Reduced miR-511-5p expressions were negatively correlated with histology/differentiation, invasion and TNM stage. Moreover, miR-511-5p was capable of being an independent prognostic predictor for CRC patients. It was also observed that overexpression of miR-511-5p depressed CRC cell growth and invasive abilities, and stimulated apoptosis. Mechanistically, we showed that miR-511-5p targeted the 3'-UTR of GPR116 and GPR116 reversed partial function of miR-511-5p in vitro. CONCLUSIONS: MiR-511-5p may be used as a novel prognostic biomarker and functions as a novel anti-oncogene in CRC and the anti-oncogenic activity may involve its inhibition of the target gene GPR116.