Figure 2.

The lack of XPC is responsible for the hypersensitivity to KBrO₃ of human fibroblasts. Normal and XP-C fibroblasts were transiently transfected with an expression vector encoding for the EGFP-XPC fusion protein (pEGFP-XPC) or with the empty vector encoding for EGFP only (pEGFP-C1). At 24 h after transfection, cells were either untreated (control) or exposed to different KBrO₃ doses (5 and 10 mM). At 48 h after transfection, cells were stained with PI to label in red dead cells, cytocentrifuged on slides and then analysed by fluorescence microscopy. (A–D) The photographs are representative fields of normal fibroblasts expressing the EGFP-XPC chimera (green fluorescence) and stained with PI to evaluate their viability following KBrO₃ treatment (red fluorescence). Examples of cells expressing the ectopic protein and either dead (A–B) or alive (C–D). (E) The histograms report the percentages of dead cells following KBrO₃ treatment of normal (F N1RO) and XP-C (F XP26PV) cells transfected with either the pEGFP-XPC or the pEGFP-C1 plasmid DNA. The reported values are the mean of at least three independent experiments and standard deviations are indicated.