2004 Fiscal Year Final Research Report Summary
Combination effect of photofrin and ALA for photodynamic therapy on experimental tongue squamous cell carcinoma in mice
| Project/Area Number |
15592104
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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 Fukui (2004)
福井医科大学 (2003) |
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Principal Investigator |
OGASAWARA Toshiyuki University of Fukui Hospital, Lecturer, 医学部附属病院, 講師 (20260565)
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| Co-Investigator(Kenkyū-buntansha) |
MIYOSHI Norio University of Fukui, Faculty of Medicine, Assistant, 医学部, 助手 (40209961)
SANO Kazuo University of Fukui, Faculty of Medicine, Professor, 医学部, 教授 (20145270)
KITAGAWA Yoshimasa Hokkaido University, Graduate School of Dental Medicine, Professor, 大学院・歯学研究科, 教授 (00224957)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Tongue Cancer / Photodynamic therapy / 5-Aminolevulinic Acid / Protoporphyrin-IX / Deferoxamine Mesilate / Cancer Treatment |
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| Research Abstract |
5-aminolevulinic acid (ALA)-induced protoporphyrin-IX (Pp-IX) has been used as a photosensitizer in photodynamic therapy (PDT) for oral cancer treatment. This study investigates the optimal method of administrating ALA by analyzing Pp-IX fluorescence in tongue tumor tissue. The influence of iron chelator on Pp-IX accumulation in the tumor tissue is also examined.
Pp-IX intensities in the mouse transplanted tongue cancer were compared with those in normal tongue after intraperitoneal, oral, or topical administration of ALA. The effects of ALA in combination with iron chelator (desferoxamine mesilate) administration were also examined. Iron chelator was administrated simultaneously or 1, 2, or 3hr before administration of ALA. Pp-IX concentration(μM) was obtained from a serial frozen sections of each sample by using a spectrophotometer.
Maximum Pp-IX accumulation in the tongue tumor tissue was seen at 5h after the oral administration of ALA. When the iron chelator was administrated intraperitoneally 1hr before oral administration of ALA, Pp-IX accumulation in the tongue tumor tissues was remarkable enhanced. Pp-IX intensity in this iron chelator combination group peaked at 3h after oral administration of ALA, which was about twice as high as that in the tumor group given ALA alone without iron chelator.
These results suggested that oral administration was the most effective administration method for ALA in combination with iron chelator in ALA-PDT for oral cancer. This method would be expected to enhance the therapeutic effect and to reduce the side effects and treatment time because the combination of iron chelator increased the Pp-IX intensity and hastened the Pp-IX accumulation and excretion in the tumor tissue.
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