| Project/Area Number |
01870069
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| Research Category |
Grant-in-Aid for Developmental Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Research Field |
Urology
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| Research Institution | Yokohama City University |
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Principal Investigator |
KUBOTA Yoshinobu Yokohama City Univ. School of Medicine Associate Professor, 医学部, 助教授 (10106312)
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| Co-Investigator(Kenkyū-buntansha) |
FUJISHIMA Akira The University of Tokyo, Dept. Synthetic Chemistry, Professor, 工学部, 教授 (30078307)
HOSAKA Masahiko Yokohama City Univ. School of Medicine Professor, 医学部, 教授 (30106330)
加藤 隆史 東京大学, 工学部, 助手 (70214377)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥5,300,000 (Direct Cost: ¥5,300,000)
Fiscal Year 1991: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1989: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Photo-chemical reaction / Photoexcited Ti02 / Human cancer cells / Semi-conductor Particles / Human Bladder cancer / Cancer treatment / ヒト膀胱癌 / 細胞膜 |
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| Research Abstract |
Photo-excited Ti02 semiconductor particles can drive various chemical reactions due to their strong oxidizing and reducing ability. To investigate the possible use of this effect for cancer treatment, the anti-tumor activity of photo-excited Ti02 particles were studied in vitro and in vivo. Human cancer cells, like T-24 human bladder cancer cells and HeLa cells, cultured in vitro were completely killed in the presence of Ti02 with photo-irradiation by a 500 W Hg lamp. In cotrast, very little cell death was observed by Ti02 treatment without photo-irradiation. Photoexcited Ti02 particles also suppressed growth of human cancer cells implanted in nude mice significantly, compared with those receiving Ti02 alone or photo-irradiation alone. The cell death caused by photo-excited Ti02 particles was significantly protected in the presence of L-tryptophan and catalase. These molecules are quenchers of hydroxyl radicals(OH^.) and scavengers of hydrogen peroxide (H_2O_2), respectively, suggesting that the cells were killed by the OH^. and H_2O_2 produced from photo-excited Ti02 particles. On the basis of these experimental observation, it can concluded that the cell killing effect of Ti02 under UV light irradiation could be adopted as one of anti-cancer modality.
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