2001 Fiscal Year Final Research Report Summary
Investigation of Enviromental Factors for Oral Cancer Screening
| Project/Area Number |
12671964
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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 | TOKYO DENTAL COLLEGE |
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Principal Investigator |
YAMANE Gen-yuki TOKYO DENTAL COLLEGE, Department of Dentistry, PROFFSSOR, 歯学部, 教授 (80096510)
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| Co-Investigator(Kenkyū-buntansha) |
TONOGI Morio Tokyo Dental College, Department of Dentistry, LECTURER, 歯学部, 講師 (50217519)
TANAKA Yoichi Tokyo Dental College, Department of Dentistry, ASSITANT PROFESSOR, 歯学部, 助教授 (30085831)
NOMA Hiroyasu Tokyo Dental College, Department of Dentistry, PROFESSOR, 歯学部, 教授 (40085791)
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| Project Period (FY) |
2000 – 2001
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| Keywords | Oral Cancer / Epithelial Dysplasia / p53 gene / early diagnosis |
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| Research Abstract |
A study was conducted in rats with early tongue carcinoma induced by 4-nitroquinoline 1-oxide (4NQO), in order to investigate the early diagnosis of malignant potential of epithelial dysplasia.
The rat tongue lesions were classified by their severity into three groups corresponding to early cancer, dysplasia and no change. The grade of epithelium was determined according to 13 items of WHO Epithelial Dysplasia Criteria.
The expression levels of p53 and Bcl-2 proteins were detected immunohistochemically, and apoptotic cells were detected using the TUNEL method. In addition, a p53 mulation by lesions was detected. The expression ratio of p53 protein was high in dysplasia, and the ratio of Bcl-2 protein was high in early cancer and dysplasia. The TUNEL-positive cells were obscrved primarily in the granular layers of the no change cells, and their numbers decreased as the cells shifted to the early cancer stage. The p53 mutation was detected using a microdissection method in dysplasia, where it was found in three out of nine lesions. All the mutations in dysplasia detected were on the same codon that was found to be mutated in the early cancer.
These results indicate that the association between the p53 mutation and histological changes in canceration of epithelial dysplasia is strong, and that both the identification of p53- and Bcl-2- positive epithelium, and decrease in the TUNEL positive ratio, were useful for the diagnosis of the malignant potential of precancerous lesions.
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Research Products
(1 results)
