Fig. 4.

CP-8 has superior cysteine oxidation-dependent radio-sensitizing propertiescomparedto CP-23. MDA-MB-231 and MCF10A cells were seeded at low density, and subjected to various doses of IR in the presence of either DMSO, CP-23, or CP-8, and colony formation was analyzed after 7 days by crystal violet staining. Colony formation was quantified as survival relative to respective 0Gy controls after supplementation with either CP-8 (A-B) or CP-23 (C-D). Data plotted as Average ± SEM (N = 3) and fit to a one-phase exponential decay function to calculate EC50 values. Statistical significance was determined by a two-tailed student's t-test. E. PRDX1 WT or shPRDX1 MBA-MB-231 cells were irradiated as in (A-D) in the presence of either DMSO or CP-8. Colony formation was quantified as survival relative to PRDX1 WT 0Gy control. Data plotted as Average ± SEM (N = 3) and fit to a one-phase exponential decay function. Statistical significance was determined by two-way ANOVA followed by Tukey's test for multiple comparisons of AUCs. Representative images for all colony formation experiments are included in each panel. ***, p < 0.001, **, p < 0.01, *, p < 0.05.