Figure 4

CALR mutations affect the capacity to repair oxidative stress-induced DNA damage. (a) Results of flow cytomeric analysis of the phosphorylation of H2AX at serine 139 (γH2AX) in K562 cells expressing either wt or mutated CALR after 24 h of treatment with Melittin 5 μg/mL (white bars) and after 24 h of repair (black bars) Data are reported as mean of the percentage of γH2AX-positive cells ± S.E.M of 3 independent experiments. (b) 8-OHdG levels measured in K562 cells expressing either wt or mutated CALR after 24 h of treatment with Melittin 5 μg/mL and after 24 h of repair. Data are reported as mean of 8-OHdG levels (expressed in ng/mL) ± S.E.M of 3 independent experiments. (c) Results of flow cytomeric analysis of ROS level in K562 cells expressing either wt or mutated CALR after 24 h of treatment with Melittin 5 μg/mL and after 24 h of repair. Data are reported as mean of the percentage of ROS-positive cells ± S.E.M of 3 independent experiments. (d) Results of SOD activity measurements. SOD activity for each sample is reported as normalized to the SOD activity of the sample collected before MEL treatment. Data are reported as mean ± S.E.M of 3 independent experiments. Abbreviations: NT, Not Treated, MEL, Melittin. *p < 0.05.