Norcantharidin induces apoptosis in human glioma cell via mitochondrial pathway

Objective To elucidate the molecular mechanism of norcantharidin (NCTD) in inducing apoptosis of glioma cells. Methods Glioma C6 cells were treated with various dosages of NCTD (25, 50, 100, 200 μmol/L) for 24, 48 h. The cell growth inhibition was measured by methyl thiazol tetrazolium (MTT) assay. The apoptosis of cells were analyzed by Annexin V-fluoresceine isothiocyanate (FITC)/propidium iodide (PI) staining. The signaling pathway changes were detected by Western blotting. Results NCTD effectively inhibited cell proliferation of C6 cells in a time and dose-dependent manner. The 24 h and 48 h half maximal inhibitory concentration (IC50) were 96.5 and 48.7 μmol/L. It had a significant inhibition of cell proliferation at 24 h and 48 h (F=78.202, 897.714, P=0.000). Compared with the control group (0.9±3.1)%, after 10 h treatment, the cell apoptosis rates induced by 10, 30, 50 μmol/L NCTD were (2.0±2.9)%, (8.4±4.1)% and (19.7±5.7)%, respectively, which indicated that NCTD could induce apoptosis of cells in a dose-dependent manner (F=76.246, P=0.000). Meanwhile, the expression levels anti-apoptotic proteins B cell lymphoma/leukemia-2 (bcl-2) and Mcl-1 were significantly reduced. Conclusion NCTD inhibits glioma cell growth and induces cell apoptosis, and the anticancer activity of NCTD may be induced through targeting bcl-2 anti-apoptotic family members. Key words: Glioma; Norcantharidin; Apoptosis; B cell lymphoma/leukemia-2 gene