@article{oai:repo.qst.go.jp:00043560,
 author = {Lan, Yin Hong and Suzuki, Yuka and Matsumoto, Yoshihisa and Tomita, Masanori and Furusawa, Yoshiya and Enomoto, Atsushi and Morita, Akinori and Aoki, Mizuho and Yatagai, Fumio and Hosoi, Yoshio and Ohtomo, Kuni and Suzuki, Norio and 松本 義久 and 冨田 雅典 and 古澤 佳也 and 青木 瑞穂 and 谷田貝 文夫 and 細井 義夫 and 鈴木 紀夫},
 journal = {Radiation Research},
 month = {},
 note = {Hyperthermia has radiosensitizating effect, which is one of the most important biological bases for its use in cancer therapy with radiation.  Although the mechanism of this effect has not been clarified in molecular terms, possible involvement of either one or both of two major DNA double-strand break (DSB) repair pathways, i.e., non-homologous end-joining (NHEJ) and homologous recombination (HR), has been speculated.  To test this possibility, we examined chicken B lymphocyte cell line DT40 and its derivatives lacking NHEJ and/or HR: KU70-/-, DNA-PKcs-/-/-, RAD54-/- and KU70-/-/RAD54-/-.  Hyperthermic radiosensitization could be seen in all of the mutants, including KU70-/-/RAD54-/-, which lacked both NHEJ and HR.  Therefore, hyperthermic radiosensitization cannot be explained simply by the inhibitory effects, if any, on typical NHEJ and/or HR alone.  However, in NHEJ-defective KU70-/- and DNA-PKcs-/-/-, consisting of two subpopulations with distinct radiosensitivity, the radiosensitive subpopulation, which is considered cells in G1 and early S, was not sensitized: substantial sensitization was seen only in the radioresistant subpopulation, which is considered cells in late S and G2, capable of repairing DSBs through HR.  This observation did not exclude possible involvement of NHEJ in G1 and early S phases and also suggested some inhibitory effects of hyperthermia on HR.  Thus, partial contribution of NHEJ and HR in hyperthermic radiosensitization, especially that depending on the cell cycle stages, remains to be considered.},
 pages = {433--441},
 title = {Radiosensitization by hyperthermia in the chicken B-lymphocyte cell line DT40 and its derivatives lacking nonhomologous end joining and/or homologous recombination pathways of DNA double-strand break repair},
 volume = {162},
 year = {2004}
}