@article{oai:nagasaki-u.repo.nii.ac.jp:00005937,
 author = {Amornwichet, Napapat and Oike, Takahiro and Shibata, Atsushi and Ogiwara, Hideaki and Tsuchiya, Naoto and Yamauchi, Motohiro and Saitoh, Yuka and Sekine, Ryota and Isono, Mayu and Yoshida, Yukari and Ohno, Tatsuya and Kohno, Takashi and Nakano, Takashi},
 issue = {12},
 journal = {PLoS ONE},
 month = {Dec},
 note = {Background and Purpose: To understand the mechanisms involved in the strong killing effect of carbon-ion beam irradiation on cancer cells with TP53 tumor suppressor gene deficiencies.Copyright:
Materials and Methods: DNA damage responses after carbon-ion beam or X-ray irradiation in isogenic HCT116 colorectal cancer cell lines with and without TP53 (p53+/ + and p53-/-, respectively) were analyzed as follows: cell survival by clonogenic assay, cell death modes by morphologic observation of DAPI-stained nuclei, DNA doublestrand breaks (DSBs) by immunostaining of phosphorylated H2AX (γH2AX), and cell cycle by flow cytometry and immunostaining of Ser10-phosphorylated histone H3.
Results: The p53-/- cells were more resistant than the p53+/+ cells to X-ray irradiation, while the sensitivities of the p53+/+ and p53-/- cells to carbon-ion beam irradiation were comparable. X-ray and carbon-ion beam irradiations predominantly induced apoptosis of the p53+/+ cells but not the p53-/- cells. In the p53-/- cells, carbon-ion beam irradiation, but not X-ray irradiation, markedly induced mitotic catastrophe that was associated with premature mitotic entry with harboring longretained DSBs at 24 h post-irradiation.
Conclusions: Efficient induction of mitotic catastrophe in apoptosis-resistant p53- deficient cells implies a strong cancer cell-killing effect of carbon-ion beam irradiation that is independent of the p53 status, suggesting its biological advantage over X-ray treatment., PLoS ONE, 9(12), e115121; 2014},
 title = {Carbon-Ion Beam Irradiation Kills X-Ray-Resistant p53-Null Cancer Cells by Inducing Mitotic Catastrophe},
 volume = {9},
 year = {2014}
}