RRC ID 53996
著者 Matsuya Y, McMahon SJ, Tsutsumi K, Sasaki K, Okuyama G, Yoshii Y, Mori R, Oikawa J, Prise KM, Date H.
タイトル Investigation of dose-rate effects and cell-cycle distribution under protracted exposure to ionizing radiation for various dose-rates.
ジャーナル Sci Rep
Abstract During exposure to ionizing radiation, sub-lethal damage repair (SLDR) competes with DNA damage induction in cultured cells. By virtue of SLDR, cell survival increases with decrease of dose-rate, so-called dose-rate effects (DREs). Here, we focused on a wide dose-rate range and investigated the change of cell-cycle distribution during X-ray protracted exposure and dose-response curves via hybrid analysis with a combination of in vitro experiments and mathematical modelling. In the course of flow-cytometric cell-cycle analysis and clonogenic assays, we found the following responses in CHO-K1 cells: (1) The fraction of cells in S phase gradually increases during 6 h exposure at 3.0 Gy/h, which leads to radio-resistance. (2) Slight cell accumulation in S and G2/M phases is observed after exposure at 6.0 Gy/h for more than 10 hours. This suggests that an increase of SLDR rate for cells in S phase during irradiation may be a reproducible factor to describe changes in the dose-response curve at dose-rates of 3.0 and 6.0 Gy/h. By re-evaluating cell survival for various dose-rates of 0.186-60.0 Gy/h considering experimental-based DNA content and SLDR, it is suggested that the change of S phase fraction during irradiation modulates the dose-response curve and is possibly responsible for some inverse DREs.
巻・号 8(1)
ページ 8287
公開日 2018-5-29
DOI 10.1038/s41598-018-26556-5
PII 10.1038/s41598-018-26556-5
PMID 29844494
PMC PMC5974424
MeSH Animals CHO Cells / radiation effects Cell Cycle / radiation effects* Cell Division Cell Survival / radiation effects* Cricetulus DNA Damage / radiation effects Dose-Response Relationship, Radiation* Models, Biological Radiation, Ionizing S Phase
IF 3.998
引用数 12
リソース情報
ヒト・動物細胞 CHO-K1(RCB0285)