CC3 impairs repair of oxidative DNA damage and reduces levels of nucleoredoxin RNA and protein. (A). Comet assays were performed with U373neo and cc3 cells, either untreated (UT) or treated with 25 μM hydrogen peroxide for 15 mins, after witch peroxide was removed and cells were allowed to recover in fresh medium for additional 15 and 30 minutes. Results are average of three independent experiments. (B). Same as in (A), with N417neo and cc3 cells except the concentration of H2O2 was 10 μM. (C). Quantitative RT-PCR of steady-state NXN RNA levels was performed with RNAs isolated from the cells with or with exogenously introduced CC3. (D) Western blot analysis of nucleoredoxin expression in paired cells, control transfected (neo) or stably transfected with CC3. E. Viability of U373 clones subjected to treatment with 100 μM H2O2 for 30 minutes. Cells were analyzed as described in Materials and methods; experiments were performed three times with cells plated in triplicate or quadruplicate for each experimental point.