TY - JOUR
T1 - Chromosome aberrations in normal human fibroblasts analyzed in G0/G1 and G2/M phases after exposure in G0 to radiation with different linear energy transfer (LET)
AU - Liu, Cuihua
AU - Kawata, Tetsuya
AU - Furusawa, Yoshiya
AU - Zhou, Guangming
AU - Inoue, Kohei
AU - Fukada, Junichi
AU - Kota, Ryuichi
AU - George, Kerry
AU - Cucinotta, Francis
AU - Okayasu, Ryuichi
N1 - Funding Information:
The authors thank the staff of the HIMAC for their help with the heavy-ion irradiation. The authors also thank Dr. M. Noguchi for technical help in flow cytometry. This study was supported by a research project with Heavy Ions at NIRS-HIMAC and in part by Japan Society for the Promotion of Science (JSPS) KAKENHI grants 24591859 , 24249067 and 23591849 . The authors gratefully acknowledge Mr. Takuo Takihana for his support and assistance during this study.
PY - 2013/5/30
Y1 - 2013/5/30
N2 - We have studied the induction of chromosome aberrations in human fibroblasts exposed in G0/G1 to X-rays or heavy ions to study the influence of G1 cell cycle arrest. Confluent normal fibroblasts were exposed to X-rays or accelerated particles with different LET values and chromosome aberrations were investigated in the first G0/G1 and G2//M phase. The particles used here were 490MeV/nucleon Si, 500MeV/nucleon Fe, and 200MeV/nucleon Fe ions. Cells were subcultured 24h after exposure and premature chromosome condensation (PCC) was performed by fusion-induced method for analysis of G0/G1 cells, and chemically-induced method for analysis of G2 and metaphase cells. Chromosome damage was assessed in chromosomes 1 and 3 using whole chromosome fluorescence in situ hybridization (FISH). Cell cycle was analyzed by flow cytometry at different incubation times following subculture. After irradiation with 2Gy of high-LET particles, the yields of chromosome aberrations and fragments were significantly higher in G0/G1 phase than in G2/M phase, whereas similar yields of damage were measured in both phases after exposure to X-rays. In contrast, the yield of misrepair, assessed by the number of color junctions, was similar in the G0/G1 and G2/M phases after exposure to either X-rays or high-LET particles. The yields of chromosome aberrations, fragments, and color junctions in both the G0/G1 and the G2/M phases, increased with LET up to 200keV/μm, then decreased for 440keV/μm Fe particles. A good correlation was found between chromosome aberrations in both G0/G1 and G2/M cells and survival fractions after 2Gy of different LET radiations, although the slopes were steeper for the G0/G1 cells. Flow cytometry analysis indicated that high-LET particles induce more non cycling G0/G1 cells within 48h of subculture than X-rays, suggesting that chromosome aberrations scored at the G2/M phase may not accurately describe the true radiation effect.
AB - We have studied the induction of chromosome aberrations in human fibroblasts exposed in G0/G1 to X-rays or heavy ions to study the influence of G1 cell cycle arrest. Confluent normal fibroblasts were exposed to X-rays or accelerated particles with different LET values and chromosome aberrations were investigated in the first G0/G1 and G2//M phase. The particles used here were 490MeV/nucleon Si, 500MeV/nucleon Fe, and 200MeV/nucleon Fe ions. Cells were subcultured 24h after exposure and premature chromosome condensation (PCC) was performed by fusion-induced method for analysis of G0/G1 cells, and chemically-induced method for analysis of G2 and metaphase cells. Chromosome damage was assessed in chromosomes 1 and 3 using whole chromosome fluorescence in situ hybridization (FISH). Cell cycle was analyzed by flow cytometry at different incubation times following subculture. After irradiation with 2Gy of high-LET particles, the yields of chromosome aberrations and fragments were significantly higher in G0/G1 phase than in G2/M phase, whereas similar yields of damage were measured in both phases after exposure to X-rays. In contrast, the yield of misrepair, assessed by the number of color junctions, was similar in the G0/G1 and G2/M phases after exposure to either X-rays or high-LET particles. The yields of chromosome aberrations, fragments, and color junctions in both the G0/G1 and the G2/M phases, increased with LET up to 200keV/μm, then decreased for 440keV/μm Fe particles. A good correlation was found between chromosome aberrations in both G0/G1 and G2/M cells and survival fractions after 2Gy of different LET radiations, although the slopes were steeper for the G0/G1 cells. Flow cytometry analysis indicated that high-LET particles induce more non cycling G0/G1 cells within 48h of subculture than X-rays, suggesting that chromosome aberrations scored at the G2/M phase may not accurately describe the true radiation effect.
KW - Cell cycle arrest
KW - Chromosome aberration
KW - Fluorescence in situ hybridization (FISH)
KW - High-LET radiation
KW - Premature chromosome condensation (PCC)
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U2 - 10.1016/j.mrgentox.2013.05.005
DO - 10.1016/j.mrgentox.2013.05.005
M3 - Article
C2 - 23688614
AN - SCOPUS:84884205184
SN - 1383-5718
VL - 756
SP - 101
EP - 107
JO - Mutation Research - Genetic Toxicology and Environmental Mutagenesis
JF - Mutation Research - Genetic Toxicology and Environmental Mutagenesis
IS - 1-2
ER -