Tunicamycin inhibits progression of glioma cells through downregulation of the MEG-3-regulated wnt/β-catenin signaling pathway

Glioma is derived from the oncogenic transformation of brain and spinal cord glial cells, and is one of the most common primary brain tumors. Tunicamycin (TUN) can significantly inhibit glioma growth and aggressiveness by promoting apoptosis in glioma cells. The purpose of the present study was to investigate the effects of TUN on growth of glioma cells and examine the TUN-mediated signaling pathway. The inhibitory effects of TUN on apoptosis, growth, aggressiveness and cell cycle arrest of glioma tumor cells were determined by western blotting, reverse transcription-quantitative polymerase chain reaction, apoptotic assays and immunofluorescence. The results demonstrated that treatment with TUN suppressed growth, migration and invasion of glioma carcinoma cells. In addition, TUN treatment induced apoptosis of glioma cells through downregulation of Bcl-2 and P53 expression levels. Findings also indicated that TUN suppressed proliferation and arrested the glioma cells in the S phase of the cell cycle. Further analysis of the mechanisms of TUN demonstrated that TUN treatment upregulated the expression levels of maternally expressed gene (MEG)-3, wnt and β-catenin in glioma cells. Furthermore, knockdown of MEG-3 expression reversed the TUN-decreased wnt/β-catenin signaling pathway, which subsequently also reversed the TUN-inhibited growth and aggressiveness of glioma cells. In conclusion, the findings in the present study indicated that TUN treatment inhibited growth and aggressiveness through MEG-3-mediated wnt/β-catenin signaling, suggesting that TUN may be an efficient anticancer agent for the treatment of glioma.