MicroRNA-520c inhibits glioma cell migration and invasion by the suppression of transforming growth factor-β receptor type 2

Abstract

Dysregulation of microRNAs (miRNAs) is actively involved in the development and progression of glioma. miR-520c was previously found to inhibit glioblastoma cell migration. However, the clinical significance of miR-520c and its biological function in glioma remain largely unknown. In the present study, we found that miR-520c expression in glioma tissues was significantly decreased compared to adjacent non-cancerous tissues. The low level of miR-520c was prominently correlated with advanced World Health Organization (WHO) grade and decreased overall survival of glioma patients. Overexpression of miR-520c in U251 cells significantly decreased the migration and invasion of the cancer cells, while miR-520c silencing promoted U87 cell migration and invasion in vitro. Mechanistically, miR-520c inversely regulated transforming growth factor-β receptor type 2 (TGFBRII) abundance in the glioma cells. Herein, TGFBRII was found to be a downstream target of miR-520c in glioma. Furthermore, an inverse correlation between TGFBRII and miR-520c expression was observed in the glioma cases. In constrast, restoration of TGFBRII expression abrogated the effects of miR-520c overexpression in U251 cells with increased cell migration and invasion. In addition, miR-520c overexpression blocked TGF-β1-induced cell migration and invasion in U251 cells. Collectively, miR-520c may serve as a prognostic predictor and a therapeutic target for glioma patients.