量研学術機関リポジトリ「QST-Repository」は、国立研究開発法人 量子科学技術研究開発機構に所属する職員等が生み出した学術成果（学会誌発表論文、学会発表、研究開発報告書、特許等）を集積しインターネット上で広く公開するサービスです。 Welcome to QST-Repository where we accumulates and discloses the academic research results(Journal Publications, Conference presentation, Research and Development Report, Patent, etc.) of the members of National Institutes for Quantum and Radiological Science and Technology.
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Caffeine sensitizes cells to ionizing radiation and this effect is believed to be associated with the disruption of DNA damage-responsive cell cycle checkpoints, which is controlled by ATM. Recent studies suggest that misrejoining of dsbs is one of the underlying mechanisms of A-T cell hyper radiosensitivity. In this study, we investigated the effects of caffeine and radiation on non-growing G-0 phase normal human fibroblast cells by determining cell survival and scoring aberrations in calyculin-A induced G2 chromosomes. Results from the cell survival study indicate that after X-ray exposure G0 cells were sensitized by 24-h treatment with caffeine. Analysis of chromosome aberrations using FISH (fluorescence in situ hybridization) revealed a high frequency of aberrant cells and color-junctions in the caffeine treated cells. Since the majority of DNA repair in non-growing G-0 cells is believed to undergo non-homologous end joining (NHEJ), caffeine may influence the fidelity of NHEJ pathway in irradiated G-0 phase cells.
Caffeine sensitizes nondividing human fibroblasts to X rays by inducing a high frequency of misrepair
