MicroRNA-34a inhibits cell growth and migration in human glioma cells via MMP-9

The present study was designed to investigate the function of matrix metalloproteinase-9 (MMP-9) in human glioma cells and the potential regulatory mechanisms. Reverse transcription-quantitative polymerase chain reaction was used to analyze the expression of MMP-9 and microRNA-34a (miR-34a) in the plasma of patients with glioma and healthy volunteers. MTT and Transwell assays were used to assess cell growth and migration, respectively. Annexin-V/propidium iodide staining was used to measure cell apoptosis. In addition, MMP-9 expression was measured using western blot analysis. In patients with glioma, MMP-9 expression was increased, while miR-34a expression was suppressed, compared with the normal group. Overall survival (OS) and disease-free survival (DFS) of patients with high MMP-9 expression were decreased compared with those with low MMP-9 expression. OS and DFS of patients with low miR-34a expression were decreased compared with those with high miR-34a expression. Downregulation of miR-34a promoted cell growth and migration, and inhibited apoptosis in U251-MG glioma cells. However, overexpression of miR-34a inhibited cell growth and migration, and induced apoptosis in glioma cells. Furthermore, downregulation of miR-34a using anti-miR-34a induced MMP-9 protein expression in glioma cells; whereas, overexpression of miR-34a suppressed MMP-9 protein expression in glioma cells. SB-3CT, an inhibitor of MMP-9, attenuated the effects of miR-34a mimic on glioma cells. Together, these results indicated that miR-34a inhibited cell growth and migration in human glioma cells by regulating MMP-9.