Low expression of microRNA-320b correlates with tumorigenesis and unfavorable prognosis in glioma.

Accumulating evidence demonstrates that dysregulated microRNAs (miRNAs) play a critical role in tumorigenesis and progression of various cancers. miR-320b, a member of miR‑320 family, was revealed downregulated in numerous human cancers, including nasopharyngeal carcinoma and colorectal cancer. However, the function of miR‑320b in human glioma remained poorly defined. In this study, we report that miR‑320b was lowly expressed in glioma tissues and cell lines in contrast with controls, being closely correlated with histological malignancy of glioma. Furthermore, patients with low expression of miR‑320b were associated with poor prognostic outcomes. In vitro functional assays indicated that overexpression of miR‑320b could markedly enhance cell apoptosis rate and suppress cell proliferation, migration and invasion. miR-320b mimic impaired cell cycle and metastasis through inhibiting the expression of G1/S transition key regulator Cyclin D1 as well as decreasing the expression level of MMP2 and MMP9. Additionally, upregulation of miR‑320b could markedly promote apoptosis by increasing the level of Bax and reducing Bcl-2 expression in glioma. Taken together, our data suggested that miR‑320b might serve as a novel prognostic marker and potential therapeutic target for glioma.