FIGURE 7.
p22phox-generated H2O2 causes DNA double strand breaks in 32D cells transfected with FLT3-ITD and not with FLT3-WT. A, Western blotting analysis of p22phox expression in 32D/FLT3-ITD and 32D/FLT3-WT in the presence/absence of IL-3 and following the PKC412 treatment (100 nm). B, Western blot analysis of the p22phox protein level at 24 h following the siRNA transfection. Ctrl refers to scrambled siRNA-treated control, A and B refer to different predesigned siRNA sequences. GAPDH was used as a loading control. C, flow cytometric analysis of cellular H2O2, measured with PO1 probe in 32D/FLT3-ITD and 32D/FLT3-WT at 24 h following the siRNA transfection. D, flow cytometric analysis of DNA DSBs, measured with γ-H2AX in 32D/FLT3-ITD and 32D/FLT3-WT at the 24 h following the p22phox siRNA transfection as indicated in the legend. The bar charts show the relative mean fluorescence of siRNA-transfected cells expressed as a percentage of control. The mean is representative of three independent experiments. The asterisk indicates a statistically significant difference (p < 0.05) as analyzed by Student's t test. The error bars represent ± S.D.