Fig. 5.

CP-8 inhibits HR more potently than CP-23. A and B. MM231 cells were treated with vehicle or 4 μM CP-8 or CP-23 for 24 h and then processed for cell cycle analysis (propidium iodide DNA staining) with flow cytometry. Mean ± SD, N = 3. C and D. U2OS cells containing the HR reporter construct DR-GFP were transfected with an I-SceI plasmid and treated with vehicle (gray) 1.3 μM of OA, CP-6, CP-8, or CP-23. Negative control cells did not have I-SceI present. Vehicle (DMSO) and oleic acid (OA) were included as controls. Average + SEM, n ≥ 3. E and F: 1.3 μM CP-8 or CP-23 treatment effects on RAD51 nucleoprotein formation after 5 Gy ionizing radiation exposure. MDA-MB-231 cells (150,000 cells/coverslip) nitroalkene 30 min after dosing cells with 5 Gy inhibited irradiation-induced RAD51 foci formation as detected by immunofluorescent confocal microscopy. Cells were processed 6 h after IR, images were acquired using a Nikon A1R confocal microscope with 60 × oil objective, and the acquisition was performed using NIS Elements software. Quantification of z-stacks and foci was completed using ImageJ software—average + SEM n = 3. One-way ANOVA was used to test the significance.