Downregulation of miR-124 promotes the growth and invasiveness of glioblastoma cells involving upregulation of PPP1R13L.

microRNA-124 (miR-124) plays an important role in regulating growth, invasiveness, stem-like traits, differentiation and apoptosis of glioblastoma cells. PPP1R3L, an inhibitory member of the apoptosis-stimulating protein of p53 family (IASPP), is also able to affect growth, cell cycle progression, metastasis and apoptosis of various types of cancer. To investigate the regulation of PPP1R13L expression by miR-124 and their effects on proliferation, cell cycle transition and invasion in glioblastoma cells, U251 and U373 glioblastoma cells were transfected with miR-124 mimics, its negative control (NC) or an inhibitor. We found that miR-124 was downregulated in glioblastoma tissues, and inversely regulated PPP1R13L expression in U251 and U373 glioblastoma cells. PPP1R13L was found to be a direct target of miR-124 in glioblastoma cells. Overexpression of miR-124 inhibited proliferation, G1/S transition and invasiveness in glioblastoma cells. miR-124 downregulation-mediated malignant progression of glioblastoma was partly attributed to increased PPP1R13L expression. Consequently, our findings provide a molecular basis for the role of miR-124/PPP1R13L in the progression of human glioblastoma and suggest a novel target for the treatment of glioblastoma.