@article{oai:repo.qst.go.jp:00046077,
 author = {Takahashi, Takeo and Hirayama, Ryoichi and Furusawa, Yoshiya and Ando, Koichi and Nakano, Takashi and et.al and 高橋 健夫 and 平山 亮一 and 古澤 佳也 and 中野 隆史},
 issue = {6},
 journal = {Anticancer Research},
 month = {Jun},
 note = {BACKGROUND: To investigate the differences between two rat yolk sac tumor cell lines with different radiosensitivities and p53 status in sensitivity to high-LET heavy-ion beam and in sensitizing effect of etoposide or cisplatin in combination with heavy-ion beam. MATERIALS AND METHODS: NMT-1 (wild-type p53 cell) is a parent radiosensitive cell line and NMT-1R (mutant-type p53 cell) is a variant radioresistant cell line. Heavy ion (carbon ion) was accelerated to 290 MeV per nucleon by a heavy-ion medical accelerator in Chiba at National Institute of Radiological Sciences. The effects of carbon ion irradiation and carbon ion irradiation plus chemotherapeutic agents were assessed by clonogenic assay. RESULTS: There was no significant difference between NMT-1 cells and NMT-1R cells in sensitivity to high-LET heavy-ion irradiation. The RBE of carbon beam was larger in mutant-type p53 cells than in wild-type p53 cells. Etoposide showed a supra-additive effect in combination with carbon beam irradiation in NMT-1R cells. Etoposide potentiation in NMT-1R cells was manifested by the decrease in the slope of the radiation dose-response curve. On the other hand, cisplatin had no enhancement of radiosensitivity in either cell lines. CONCLUSION: Our findings suggested that high-LET radiotherapy is expected to be effective for patients carrying radioresistant tumors and mutated p53 tumor cells. Etoposide might be effective for radioresistant tumors in combination with heavy-ion beam irradiation.},
 pages = {1961--1967},
 title = {In vitro interaction of high-LET heavy-ion irradiation and chemotherapeutic agents in two cell lines with different radiosensitivities and different p53 status},
 volume = {30},
 year = {2010}
}