MicroRNA­940 promotes cell proliferation and invasion of glioma by directly targeting Kruppel­like factor 9.

MicroRNA­940 (miR­940) has been extensively studied in the pathogenesis of numerous types of human cancer; however, the expression pattern, roles and molecular mechanisms underlying the regulatory actions of miR­940 in glioma remain unknown. The present study aimed to further investigate miR­940 by studying its expression, roles and mechanisms of action in glioma. Reverse transcription­quantitative polymerase chain reaction (RT­qPCR) was used to detect miR­940 expression in glioma tissues and cell lines. The regulatory effects of miR­940 in glioma cell proliferation and invasion were determined using MTT and cell invasion assays. Bioinformatics analyses was performed to identify the potential target of miR­940, which was further confirmed by luciferase reporter assay, RT­qPCR and western blot analysis. In the present study, significantly increased miR­940 expression levels were observed in glioma tissues and cell lines compared with normal brain tissues and normal human astrocytes, respectively. Decreased miR­940 expression levels attenuated glioma cell proliferation and invasion in vitro. Kruppel­like factor 9 (KLF9) was predicted as a potential target of miR­940. Further assays demonstrated that miR­940 negatively regulated KLF9 expression in glioma cells by directly targeting the 3'­untranslated regions of KLF9. Additionally, KLF9 expression was downregulated in glioma tissues and was inversely correlated with miR­940. Furthermore, KLF9 knockdown was able to rescue the effects of miR­940 on glioma cell proliferation and invasion. The results of the present study suggest that miR­940 may function as an oncogene in glioma by targeting KLF9 and may be a considered a therapeutic target for the treatment of gliomas.