| Project/Area Number |
13672080
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Surgical dentistry
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| Research Institution | University of Tsukuba |
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Principal Investigator |
ONIZAWA Kojiro University of Tsukuba, Institute of Clinical Medicine, Assistant Professor, 臨床医学系, 講師 (60194578)
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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 |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2003: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2002: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | Fluorescence / Oral Cancer / Aminorevulinic acid / Photodynamic Therapy / Autofluorescence |
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| Research Abstract |
This study was carried out to investigate application of 5-anunorevulinic acid (ALA) for diagnosis and treatment of oral cancer. The relationship between autofluorescence and AL.A induced fluorescence was analyzed biochemically, and effect of photodynamic therapy using AIA on nude mouse tumor was evaluated histologically. The autofluorescence arising in human oral cancer was reported to be associated with protoporphyrin, and similar poiphyrins were observed in oral cancers induced in hamsters and oral-cancer cell lines. After topical or systemic administration of ALA, red fluorescence which was similar to autofluorescence in human cancer was observed in oral mucosa and cancer induced in hamster. Red fluorescence was also observed in slap and tumor formed by human oral-cancer cell lines under administration of AIA. The fluorescent substance associated with ALA was suggested to be protoporphyrin, which was consistent with those caused autofluorescence in human cancer. The enhanced intensity of red fluorescence was also demonstrated in cancer tissues of hamster or nude mouse under administration of ALA, and ALA could be applied to fluorescence diagnosis for oral cancer to enhance intensity of autofluorescence in early-staged or small-sized cancer. Although ALA-based photodynamic therapy was evaluated in nude mouse honor under various experimental conditions, tumor necrosis was observed in only superficial area and nodular tumor did not show any regression after the therapy. Further experiments would be necessary before clinical application of ALA-based photodynamic therapy for nodular cancer tissue
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