Fig. 4
Increased intracellular oxidative stress plays a protective role in penfluridol-induced apoptosis of acute myeloid leukemia (AML) cells. a and b Fms-like tyrosine kinase 3 (FLT3)-wild type (WT) AML cells, U937 and HL-60, (a) or FLT3 mutant (internal tandem duplication) cells, MV4–11, (b) were treated with 7.5 μM penfluridol or 100 μM H2O2 for the indicated time, and then the reactive oxygen species (ROS) level was measured by H2DCFDA staining under a fluorescence microscope (left panel) or flow cytometric analysis (right panel). Original magnification, 200×. Data are presented as the mean ± SD. ** p < 0.01; *** p < 0.001 versus the vehicle control group. c and d U937, HL-60, and MV4–11 cells were pretreated with and without 5 mM N-acetylcysteine (NAC) (c) or glutathione (GSH) (d) for 1 h followed by treatment with 7.5 μM (U937 and HL-60) or 5 μM (MV4–11) penfluridol for 24 h; cleaved PARP and caspase-3 were detected by a Western blot analysis. β-actin served as a loading control