Fig. 5
Effect of antioxidant NAC on serum-induced ROS generation and the expression of stem cell markers in GSCs. a Effect of NAC on mitochondrial O2 − levels in GSC11 cells exposed to serum. Cells were cultured in stem cell medium with or without serum (5 % FBS) in the presence or absence of 20 mM NAC for 7 days. Mitochondrial O2 − was measured by using MitoSOX-Red. b Comparison of neurosphere formation in GSC11 cells cultured in serum-free or serum-containing medium in the presence and absence of 20 mM NAC for 7 days. c NAC suppressed serum-induced loss of CD133 expression. GSC23 cells were exposed to serum for 1, 3, or 7 days in the presence or absence of 20 mM NAC as indicated, and CD133-positive cells were quantitated by flow cytometry analysis. *P < 0.05. d GSC11 cells were exposed to serum (5 % FBS) for 3 days in the presence and absence of 20 mM NAC. The expression of SOX2 and Olig2 mRNA was measured by quantitative RT-PCR. **P < 0.001. e NAC suppressed serum-induced downregulation of the Notch pathway. GSC11 cells were incubated without or with serum (5 % FBS) for 3 days in the presence or absence of 20 mM NAC. RNA was isolated from each sample, and the expression of molecules involved in Notch signaling was measure by quantitative RT-PCR. FBS fetal bovine serum, GSC glioma stem cell, NAC N-acetyl-cysteine, O 2 − superoxide, ROS reactive oxygen species, RT-PCR reverse transcription-polymerase chain reaction