CSC inhibits NER in IMR-90 human lung fibroblasts.

<p>(A) Cell viability after CSC treatment. Confluent IMR-90 cells were treated with CSC (or mock treated with DMSO) with the concentrations shown for 24 h and the percentage of viable cells was measured using Trypan blue dye exclusion. The data represent the mean ± SE (Standard Error) from four independent experiments (except for 60 μg/ml CSC which included two independent experiments). (B) Removal of 6–4 PPs. Cells were treated with the concentrations of CSC shown or with DMSO for 24 h and irradiated with 20 J/m² UVC to introduce photolesions. After irradiation, cells were either lysed immediately or after incubation in medium containing CSC or DMSO for the times (h) shown to permit repair. The immunoblot assay to detect 6–4 PPs was performed and samples were loaded in duplicate for each repair time point. (C) Removal of 6–4 PPs. A graphical representation of results obtained from multiple immunoblots measuring the removal of 6–4 PPs is shown. Each data point represents the mean ± SE of three repeats from two independent experiments. (D) Removal of CPDs. IMR-90 cells were treated with 200 μg/mL CSC or with DMSO for 24 h and irradiated with 2 J/m² UVC to introduce photolesions. After irradiation, cells were either lysed immediately or after incubation in medium containing CSC or DMSO for the times shown to permit repair. An immunoblot assay to detect CPD lesions was performed and samples were loaded in triplicate for each time point. (E) Removal of CPDs. A graphical representation of results obtained from multiple immunoblots measuring the removal of CPDs is shown. Each data point represents the mean ± SE of three repeats from two independent experiments.