Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts

T. Kawata, M. Durante, Y. Furusawa, K. George, H. Ito, H. Wu, F. A. Cucinotta

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

We reported previously that exposure of normal human fibroblasts in G2 phase of the cell cycle to high-LET radiation produces a much higher frequency of isochromatid breaks than exposure to γ rays. We concluded that an increase in the production of isochromatid breaks is a signature of initial high-LET radiation-induced G2-phase damage. In this paper, we report the repair kinetics of isochromatid breaks induced by high-LET radiation in normal G2-phase human fibroblasts. Exponentially growing human fibroblasts (AG1522) were irradiated with γ rays or energetic carbon (290 MeV/nucleon), silicon (490 MeV/nucleon), or iron (200 MeV/nucleon) ions. Prematurely condensed chromosomes were induced by calyculin A after different postirradiation incubation times ranging from 0 to 600 min. Chromosomes were stained with Giemsa, and aberrations were scored in cells at G2 phase. G2-phase fragments, the result of the induction of isochromatid breaks, decreased quickly with incubation time. The curve for the kinetics of the rejoining of chromatid-type breaks showed a slight upward curvature with time after exposure to 440 keV/μm iron particles, probably due to isochromatid-isochromatid break rejoining. The formation of chromatid exchanges after exposure to high-LET radiation therefore appears to be underestimated, because isochromatid-isochromatid exchanges cannot be detected. Increased induction of isochromatid breaks and rejoining of isochromatid breaks affect the overall kinetics of chromatid-type break rejoining after exposure to high-LET radiation.

Original languageEnglish
Pages (from-to)598-602
Number of pages5
JournalRadiation Research
Volume156
Issue number5 II
Publication statusPublished - 2001
Externally publishedYes

Fingerprint

Heavy Ions
Linear Energy Transfer
G2 Phase
fibroblasts
interphase
heavy ions
Fibroblasts
Chromatids
chromatids
Radiation
ions
radiation
chromosomes
kinetics
rays
induction
Iron
Chromosomes
iron
Silicon

ASJC Scopus subject areas

  • Agricultural and Biological Sciences (miscellaneous)
  • Radiology Nuclear Medicine and imaging
  • Biophysics
  • Radiation

Cite this

Kawata, T., Durante, M., Furusawa, Y., George, K., Ito, H., Wu, H., & Cucinotta, F. A. (2001). Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts. Radiation Research, 156(5 II), 598-602.

Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts. / Kawata, T.; Durante, M.; Furusawa, Y.; George, K.; Ito, H.; Wu, H.; Cucinotta, F. A.

In: Radiation Research, Vol. 156, No. 5 II, 2001, p. 598-602.

Research output: Contribution to journalArticle

Kawata, T, Durante, M, Furusawa, Y, George, K, Ito, H, Wu, H & Cucinotta, FA 2001, 'Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts', Radiation Research, vol. 156, no. 5 II, pp. 598-602.
Kawata T, Durante M, Furusawa Y, George K, Ito H, Wu H et al. Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts. Radiation Research. 2001;156(5 II):598-602.
Kawata, T. ; Durante, M. ; Furusawa, Y. ; George, K. ; Ito, H. ; Wu, H. ; Cucinotta, F. A. / Rejoining of isochromatid breaks induced by heavy ions in G2-phase normal human fibroblasts. In: Radiation Research. 2001 ; Vol. 156, No. 5 II. pp. 598-602.
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