Increased Yield of Residual γH2AX Foci in p53-Deficient Human Lung Carcinoma Cells Exposed to Subpicosecond Beams of Accelerated Electrons

Bull Exp Biol Med. 2022 Apr;172(6):756-759. doi: 10.1007/s10517-022-05472-9. Epub 2022 May 2.

Abstract

We studied quantitative yield of residual (24 h post-irradiation) phosphorylated histone (γH2AX) foci as a marker of DNA double strand breaks in wild-type A549 and p53-deficient H1299 human lung carcinoma cells after exposure to subpicosecond (energy 4 MeV, pulse duration 400 fsec, peak dose rate during the pulse 16 GGy/s) and quasi-continuous (energy 3.6 MeV) beams of accelerated electrons in a dose range of 0.5-10.0 Gy. The efficiency of pulse irradiation in A549 and H1299 cells assessed by the yield of residual foci was higher than the efficiency of quasi-continuous exposure by 1.8 and 5.3 times, respectively. Significant differences in quantitative yield of residual γH2AX foci between wild-type and p53-deficient cell lines were observed only after exposure to subpicosecond, but not quasi-continuous beams of accelerated electrons.

Keywords: DNA double strand breaks; human lung carcinoma; p53; residual γH2AX foci; subpicosecond electron irradiation.

MeSH terms

  • DNA Breaks, Double-Stranded
  • DNA Repair
  • Electrons*
  • Histones* / genetics
  • Histones* / metabolism
  • Histones* / radiation effects
  • Humans
  • Lung Neoplasms* / genetics
  • Lung Neoplasms* / metabolism
  • Lung Neoplasms* / radiotherapy
  • Tumor Suppressor Protein p53* / deficiency
  • Tumor Suppressor Protein p53* / genetics
  • Tumor Suppressor Protein p53* / metabolism

Substances

  • Histones
  • TP53 protein, human
  • Tumor Suppressor Protein p53