Figure 1 | Oncogene

Figure 1

From: Selenomethionine induction of DNA repair response in human fibroblasts

Figure 1

SeMet enhanced repair of UV-damage as assayed by alkaline comet electrophoresis. Cells (normal human fibroblasts) were treated or not with SeMet, then treated or not with UV-radiation at doses indicated. The number of damage-associated strand breaks is reflected in the electrophoretic mobility of genomic DNA eluted from each nucleus, which is linear over a wide range of UV-doses. The amount of DNA in the comet tails was calculated using digital analysis software. UV-induced DNA damage was decreased in cells treated with SeMet, reflected enhancement of DNA repair. Cells not treated with UV-radiation showed little or no DNA damage, irrespective of the presence or absence of SeMet, indicating that SeMet did not by itself cause any detectable DNA damage. The data are expressed relative to the initial amount of UV-damage, which was determined by treatment immediately after UV-irradiation with E. Coli endonuclease III or Schizosaccharomyces pombe UV-cutter enzymes (Trevigen, Inc.) which cleave UV-damaged sites independently of the cellular DNA repair capability. (a) Illustration of the methodology; (b) Quantification of the data, derived from human fibroblasts treated or not with SeMet, and damaged or not by UV-irradiation. Each bar of the bar graph represents 600 or more individual cells, in which data were averaged from three independent determinations of 200 cells per determination, and a subset of 50 cells were analysed by NIH software. P<0.01 for the third and fourth bars of the graph (t-test using SigmaPlot software)

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