TY - JOUR
T1 - High-LET radiation-induced aberrations in prematurely condensed G2 chromosomes of human fibroblasts
AU - Kawata, T.
AU - Gotoh, E.
AU - Durante, M.
AU - Wu, H.
AU - George, K.
AU - Furusawa, Y.
AU - Cucinotta, F. A.
N1 - Funding Information:
This work was supported by NASA Space Radiation Health Program. T. K. is supported by an NRC grant (fellowship no. 918.71Ths08wio)kisr dedicated to the memory of Dr Tracy Yang.
PY - 2000
Y1 - 2000
N2 - 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.
AB - 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.
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U2 - 10.1080/09553000050050945
DO - 10.1080/09553000050050945
M3 - Article
C2 - 10923617
AN - SCOPUS:0033920067
SN - 0955-3002
VL - 76
SP - 929
EP - 937
JO - International Journal of Radiation Biology
JF - International Journal of Radiation Biology
IS - 7
ER -