@misc{oai:repo.qst.go.jp:00071171,
 author = {Sai, Sei and Wakai, Toshifumi and Kamada, Tadashi and 崔 星 and 鎌田 正},
 month = {Jun},
 note = {Purpose: To investigate whether a carbon ion beam has beneficial effects compared to X-ray by targeting putative cancer stem cells.
Methods: Human liver cancer stem-like cells sorted from HepG2 and Huh7 cells were treated with or without carbon ion or X-ray irradiation and then colony formation assay, spheroid formation assay, gammaH2AX foci formation assays were performed. Histopathological changes of xenograft tumors after carbon or X-ray irradiation was also examined.
Results: CD133+/CD90+ cells significantly have higher number of colony and spheroid compared to CD133-/CD90- cells. CD133+/CD90+ cells have shown more potential to form tumors in SCID mice than CD133-/CD90- cells. Colony assay showed that CD133+/CD90+ cells appeared to be radioresistant to both X-ray and carbon ion beam, but carbon beam was more effective at killing those of cancer stem-like cells. The number of gammaH2AX foci in CD133-/CD90- cells was higher than that of CD133+/CD90+ cells after irradiation with either X-ray or carbon ion beam. The number of gammaH2AX foci in CD133+/CD90+ cells was almost the same in the early time, but it persists for significantly longer in carbon ion beam irradiated cells compared to X-rays. Carbon ion irradiation with 15 Gy induced more severe xenograft tumor cell cavitation and fibrosis compared with 30 Gy X-rays, and tumors were significantly regressed following 30 Gy carbon ion irradiation. 
Conclusion: Taken together, carbon ion beam more effectively kills CD133+/CD90+ cancer stem-like cells via unrepairable DNA damage in vitro as well as tumor regression in vivo compared to X-ray., 23rd Conference of the Asian Pacific Association for the Study of the Liver (APASL 2013),},
 title = {Distinct Effects of Carbon Ion Beam and X-ray on Putative Liver Cancer Stem Cell In Vitro and In Vivo},
 year = {2013}
}