NADPH oxidase regulates the growth and apoptosis of U251 glioma cells

Abstract

Objective To investigate the effects of NADPH oxidase (NOX) on the survival,proliferation and apoptosis of U251 glioma cells. Methods RT-PCR was employed to examine the expressions of NOX genes in the U251 glioma cells. Five, 15 and 25 μmol/L diphenyleneiodonium (DPI,the NOX inhibitor) and 10 mmol/L antioxidant Tiron were added into the cells, respectively, and 24 h after that, the proliferation of U251 glioma cells was tested by alamarBlue assay, and the production of intraceilular reactive oxygen species (ROS) and the apoptosis of U251 glioma cells were examined by flow cytometry. These results were compared with those in the normal control group. Results High mRNA expression level of NOX4 gene was found in the U251 glioma cells. DPI at each concentration can inhibit the growth of U251 glinma cells and induce the apoptosis of U251 glioma cells. Compared with the normal control group, the treatment groups showed significantly decreased ROS in the U251 glioma cells (P<0.05). Conclusion NOX4 gene may be a major source that generates the intracellular ROS in the glioma cells. NOX4 gene regulates the proliferation, survival and apoptosis of glioma cells through increasing the level of ROS and then acting on its downstream regulatory molecules. Key words: NADPH oxidase; Reactive oxygen species; Diphenyleneiodonium; Glioma; Apoptosis