Hyperoxia-Induced DNA Damage Causes Decreased DNA Methylation in Human Lung Epithelial-Like A549 Cells

Academic Article


  • The effect of hyperoxia on levels of DNA damage and global DNA methylation was examined in lung epithelial-like A549 cells. DNA damage was assessed by the single-cell gel electrophoresis (comet assay) and DNA methylation status by the cytosine extension assays. Cells exposed to ionizing radiation (0, 1, 2, 4, or 8 Gy) showed increasing rates of percentage of DNA in the tail and tail length with increasing radiation dose. When cells were exposed to room air (normoxia) for 1 day and 95% O2 (hyperoxia) for 1, 2, 3, 4, and 5 days, data indicated that hyperoxia caused time-dependent increases in levels of (a) single strand breaks, (b) double strand breaks, and (c) 8-oxoguanine. Decreased DNA methylation also was observed at day 5 of hyperoxic exposure, suggesting that hyperoxia-induced DNA damage can influence patterns of DNA methylation in a lung-derived cell line.
  • Authors

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    Digital Object Identifier (doi)

    Author List

  • Panayiotidis MI; Rancourt RC; Allen CB; Riddle SR; Schneider BK; Ahmad S; White CW
  • Start Page

  • 129
  • End Page

  • 136
  • Volume

  • 6
  • Issue

  • 1