Fig. 3

Depletion of CBR1 accumulates ROS, leading to increased DNA damage and mitotic catastrophe. a, Scrambled siRNA and CBR1-siRNA were transfected into FaDu cells and then exposed to 6 Gy IR. ROS formation was analysed by FACS using a total ROS detection kit (Enzo) 24 h after IR. b, Mean fluorescence from three independent experiments (two-way ANOVA; **, P < 0.01 vs. Scrambled siRNA). c and d, Detection of γH2AX foci formation was performed 48 h after IR (6 Gy) with scrambled siRNA or CBR1 siRNA pre-treatment prior to IR. B, Error bar summarising immunofluorescent data from analysis of ~ 200 cells (two-way ANOVA; ***, P < 0.001 vs. Scrambled siRNA). e, Representative image and summary of the percentage of FaDu cells with micronuclei (arrows) 48 h following treatment with IR. Error bars show mean average from scoring ~ 200 nuclei (t-test; **, P < 0.01). f, FaDu cells were transfected with scrambled or CBR1 siRNA for 24 h and then irradiated with 2 Gy. Cells were collected at each time point thereafter and analysed by flow cytometry for the percentage of cells in G2/M (two-way ANOVA; **, P < 0.01 vs. Scrambled siRNA)