Increased susceptibility to delayed genetic effects of low dose X-irradiation in DNA repair deficient cells

Genro Kashino*, Keiji Suzuki, Seiji Kodama, Masami Watanabe, Kevin M. Prise

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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Abstract

Purpose: To examine whether the levels of micronuclei induction, as a marker for genomic instability in the progeny of X-irradiated cells, correlates with DNA repair function.

Materials and methods: Two repair deficient cell lines (X-ray repair cross-complementing 1 [XRCC1] deficient cell line [EM9] and X-ray repair cross complementing 5 [XRCC5; Ku80] deficient X-ray sensitive Chinese hamster ovary [CHO] cell line [xrs5]) were used in addition to wild-type CHO cells. These cells were irradiated with low doses of X-rays (up to 1 Gy). Seven days after irradiation, micronuclei formed in binucleated cells were counted. To assess the contribution of the bystander effect micronuclei induction was measured in progeny of non-irradiated cells co-cultured with cells that had been irradiated with 1Gy.

Results: The delayed induction of micronuclei in 1 Gy-irradiated cells was observed in normal CHO and EM9 but not in xrs5. In the clone analysis, progenies of xrs5 under bystander conditions showed significantly higher levels of micronuclei, while CHO and EM9 did not.

Conclusion: Genomic instability induced by X-irradiation is associated with DSB (double-strand break) repair, even at low doses. It is also suggested that bystander signals, which lead to genomic instability, may be enhanced when DSB repair is compromised.

Original languageEnglish
Pages (from-to)295-300
Number of pages6
JournalInternational journal of radiation biology
Volume89
Issue number4
Early online date17 Dec 2012
DOIs
Publication statusPublished - Apr 2013

Keywords

  • Genomic instability
  • bystander effect
  • DNA repair
  • low-dose irradiation
  • INDUCED GENOMIC INSTABILITY
  • DOUBLE-STRAND BREAKS
  • IONIZING-RADIATION
  • OXIDATIVE STRESS
  • CHROMOSOMAL INSTABILITY
  • IN-VIVO
  • HAMSTER-CELLS
  • DAMAGE
  • RAYS
  • INDUCTION

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