miR-517a is up-regulated in glioma and promotes glioma tumorigenesis in vitro and in vivo

miR-517a has been reported to act as an oncogenic miRNA in human hepatocellular carcinoma and lung cancer. However, the roles and underlying molecular mechanism of miR-517a in glioma remain unclear. In the present study, the expression of miR-517a in clinical glioma tissues and glioma cell lines was examined by quantitative real-time PCR (qRT-PCR). Transfected with knockdown or forced expression of miR-517a, the effects of miR-517a on cell proliferation, migration, and invasion were detected through in vitro and in vivo tumorigenesis assays. Here, we report that miR-517a expression was up-regulated in glioma tissues when compared with normal brain tissues, and up-regulation of miR-517a level is tightly correlated with the status of pathology classification of glioma. A functional assay found that overexpression of miR-517a in glioma cells markedly promoted or suppressed cell proliferation, colony formation, migration and invasion, respectively. Moreover, we revealed that the knockdown of miR-517a dramatically suppressed glioma cell growth, migration, and invasion in vitro and in vivo. Furthermore, we found that knockdown of miR-517a significantly induced apoptosis. Therefore, miR–517a acts an oncogenic miRNA that promotes tumor progression in glioma, and thus may become a promising therapeutic candidate for glioma.