@article{oai:repo.qst.go.jp:00047396,
 author = {Sato, Katsutoshi and Nishikino, Masaharu and Kawachi, Tetsuya and Shimokawa, Takashi and Imai, Takashi and Teshima, Teruki and Nishimura, Hiroaki and Kando, Masaki and 佐藤 克俊 and 下川 卓志 and 今井 高志},
 issue = {4},
 journal = {Journal of radiation research},
 month = {Apr},
 note = {While it has been expected that X-ray laser will be widely applied to biomedical studies, this has not been achieved to date and its biological effects such as DNA damage have not been evaluated. As a first step for its biological application, we developed a culture cell irradiation system, particularly designed for a plasma-driven soft X-ray laser pulse, to investigate whether the soft X-ray laser is able to induce DNA double strand breaks (DSBs) in living cells or not. The human adenocarcimona cell line A549 was irradiated with the soft X-ray laser at a photon energy of 89 eV and the repair focus formation of the DSBs was assessed by immunofluorescence staining with antiphosphorylated DNA-PKcs (p-DNA-PKcs), ATM (p-ATM) and γ-H2AX antibody. The p-DNA-PKcs, ATM, and γ-H2AX foci were clearly identified after soft X-ray laser irradiation. Furthermore, the increase in the X-ray laser shot number, even from a single shot, results in the increase in p-DNA-PKcs foci. These results are the first evidence that the 89 eV soft X-ray laser is able to induce DSB in living cells. Our study demonstrated that this irradiation system is a useful tool for investigating the radiobiological effect of soft X-ray laser.},
 pages = {633--638},
 title = {A laser-plasma-produced soft X-ray laser at 89 eV generates DNA double-strand breaks in human cancer cells.},
 volume = {56},
 year = {2015}
}