High-LET radiation-induced aberrations in prematurely condensed G2 chromosomes of human fibroblasts

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

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Abstract

Purpose: To determine the number of initial chromatid breaks induced by low- or high-LET irradiations, and to compare the kinetics of chromatid break rejoining for radiations of different quality. Material and methods: Exponentially growing human fibroblast cells AG1522 were irradiated with γ-rays, energetic carbon (290 MeV/u), silicon (490 MeV/u) and iron (200 and 600 MeV/u). Chromosomes were prematurely condensed using calyculin A. Chromatid breaks and exchanges in G2 cells were scored. PCC were collected after several post-irradiation incubation times, ranging from 5 to 600 min. Results: The kinetics of chromatid break rejoining following low- or high-LET irradiation consisted of two exponential components representing a rapid and a slow time constant. Chromatid breaks decreased rapidly during the first 10 min after exposure, then continued to decrease at a slower rate. The rejoining kinetics were similar for exposure to each type of radiation. Chromatid exchanges were also formed quickly. Compared to low-LET radiation, isochromatid breaks were produced more frequently and the proportion of unrejoined breaks was higher for high-LET radiation. Conclusions: Compared with γ-rays, isochromatid breaks were observed more frequently in high-LET irradiated samples, suggesting that an increase in isochromatid breaks is a signature of high-LET radiation exposure.

Original languageEnglish
Pages (from-to)929-937
Number of pages9
JournalInternational Journal of Radiation Biology
Volume76
Issue number7
Publication statusPublished - 2000 Jul 22

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ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging

Cite this

Kawata, T., Gotoh, E., Durante, M., Wu, H., George, K., Furusawa, Y., & Cucinotta, F. A. (2000). High-LET radiation-induced aberrations in prematurely condensed G2 chromosomes of human fibroblasts. International Journal of Radiation Biology, 76(7), 929-937.