Comparison of the repair of potentially lethal damage after low- And high-LET radiation exposure, assessed from the kinetics and fidelity of chromosome rejoining in normal human fibroblasts

Cuihua Liu, Tetsuya Kawata, Guangming Zhou, Yoshiya Furusawa, Ryuichi Kota, Atsuhiro Kumabe, Shinya Sutani, Junichi Fukada, Masayo Mishima, Naoyuki Shigematsu, Kerry George, Francis Cucinotta

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Potentially lethal damage (PLD) and its repair (PLDR) were studied in confluent human fibroblasts by analyzing the kinetics of chromosome break rejoining after X-ray or heavy-ion exposures. Cells were either held in the non-cycling G0 phase of the cell cycle for 12 h, or forced to proliferate immediately after irradiation. Fusion premature chromosome condensation (PCC) was combined with fluorescence in situ hybridization (FISH) to study chromosomal aberrations in interphase. The culture condition had no impact on the rejoining kinetics of PCC breaks during the 12 h after X-ray or heavy-ion irradiation. However, 12 h after X-ray and silicon irradiation, cycling cells had more chromosome exchanges than non-cycling cells. After 6 Gy X-rays, the yield of exchanges in cycling cells was 2.8 times higher than that in non-cycling cells, and after 2 Gy of 55 keV/μm silicon ions the yield of exchanges in cycling cells was twice that of non-cycling cells. In contrast, after exposure to 2 Gy 200-keV/μm or 440-keV/μm iron ions the yield of exchanges was similar in non-cycling and cycling cells. Since the majority of repair in G0/G1 occurs via the non-homologous end joining process (NHEJ), increased PLDR in X-ray and silicon-ion irradiated cells may result from improved cell cycle-specific rejoining fidelity through the NHEJ pathway, which is not the case in high- LET iron-ion irradiated cells.

Original languageEnglish
Pages (from-to)989-997
Number of pages9
JournalJournal of radiation research
Volume54
Issue number6
DOIs
Publication statusPublished - 2013 Nov 1

Keywords

  • FISH (fluorescence in situ hybridization)
  • Heavy ion
  • Misrepair
  • PLDR ( potentially lethal damage repair)
  • Premature chromosome condensation

ASJC Scopus subject areas

  • Radiation
  • Radiology Nuclear Medicine and imaging
  • Health, Toxicology and Mutagenesis

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