2011 Fiscal Year Final Research Report
Mechanism of Radioadaptation
| Project/Area Number |
21310040
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Risk sciences of radiation/Chemicals
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| Research Institution | Nara Medical University |
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Principal Investigator |
OHNIHI Takeo 奈良県立医科大学, 医学部, 特任教授 (60094554)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Akihisa 群馬大学, 准教授 (60275336)
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| Project Period (FY) |
2009 – 2011
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| Keywords | 放射線適応応答 / p53 / NOラジカル / 放射線感受性 / 染色体異常 / 水浸拘束マウス / ストレス / 宇宙放射線 |
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| Research Abstract |
The aim of this study was to examine biological effects of nitric oxide(NO) on radioadaptation such as the induction of radioresistance and the depression of chromosomal aberration from the cell cycle phase and p53 gene status in human cancer cells. This radioadaptation effect was observed during a clearly shortened G_2/M phase and a slightly prolonged S phase. By pre-irradiation with low dose or mild-heat treatment, we found that water-immersion stress(RWIS)-induced stomach ulcer and apoptosis in stomach cells were depressed though the induction of heat shock proteins. To clarify the biological effects of space environment, especially space radiations, a space experiment of "Rad Gene" was performed as the first life experiment with two human lymphoblastoid cell lines bearing wild-type p53 gene(wtp53) and mutated p53 gene mp53 in an International Space Station(ISS) for 133 days. The space flown cells at frozen state were cultured and then exposed to challenging X-ray-irradiation. All of the radioadaptive responses of cell killing, apoptosis, chromosomal aberrations and mutations were found only in wtp53 cells, but not in the mp53 cells.
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