| Project/Area Number |
13470187
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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 |
Radiation science
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| Research Institution | Kyushu University |
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Principal Investigator |
TSUZUKI Teruhisa Kyushu University, Faculty of Medical Sciences, Professor, 大学院・医学研究院, 教授 (40155429)
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| Co-Investigator(Kenkyū-buntansha) |
KURA Shinobu Kyushu University, Faculty of Medical Sciences, Research Associate, 大学院・医学研究院, 助手 (90037391)
NAKAMURA Katsumasa Kyushu University, Faculty of Medical Sciences, Research Associate, 大学院・医学研究院, 助手 (20284507)
SASAKI Shigeki Kyushu University, Faculty of Pharmaceutical Sciences, Professor, 大学院・薬学研究院, 教授 (10170672)
NAKATSU Yoshimichi Kyushu University, Faculty of Medical Sciences, Associate Professor, 大学院・医学研究院, 助教授 (00207820)
MORITA Takashi Osaka City University, Graduate School of Medicine, Professor, 大学院・医学研究科, 教授 (70150349)
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| Project Period (FY) |
2001 – 2003
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| Project Status |
Completed (Fiscal Year 2003)
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| Budget Amount *help |
¥14,500,000 (Direct Cost: ¥14,500,000)
Fiscal Year 2003: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 2002: ¥4,200,000 (Direct Cost: ¥4,200,000)
Fiscal Year 2001: ¥7,500,000 (Direct Cost: ¥7,500,000)
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| Keywords | DNA damage / DNA repair / Cell death / Synthetic oligomer / DNA recombination / Antigene / Radio sensitivity / Gene intervention / DNA組み換え |
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| Research Abstract |
Rad51 is a key component of the homologous recombination repair pathway. Previous experiments with the antisense oligonucleotides, designed to down-regulate Rad51 gene expression, resulted in leading to increased radiosensitivity of mouse glioma cell lines after high doses of radiation and an increased survival rate for glioma-bearing mice treated with the Rad51 antisense molecule prior to irradiation. As part of our efforts to devise strategies for enhancing the effectiveness of radiation therapy, we explored the use of RNAi(RNA interference) as a means of attenuating Rad51 expression in mouse teratocarcinoraa F9 cells in a gene therapy context. After transfection of the Rad51 siRNA(short interfering RNA), cells were cultured for two days, then irradiated by X-ray at a dose of 2 Gy. Radiosensitivity of the cells was analyzed,by MTT assay. The amount of Rad51 protein in Rad51 siRNA transfected cells was shown to approximately 30-40% of the level s expressed in control cells. The increased sensitivity of the cells to X-ray irradiation was evident when the cells were transfected with Rad51 siRNA, compared to mock-transfected cells. Furthermore, the effect of sensitization with Rad51 siRNA transfection was also observed when the cells were treated with an anti-tumor drug, cisplatin, which bind and break DNA. The concentration of cisplatin, which reduced cytotoxysicity to 50%, became 0.2μM from 0.4μM. Simultaneous exposure of the cells to X-ray irradiation and cisplatin exerted additive effect to the growth inhibition of F9 cells.
These results show the critical role of Rad51 in cellular responses to radiation as well as an anti-cancer drug, cisplatin, and indicate the potential use of Rad51-targeted RNAi in tumor radiosensitization.
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