1997 Fiscal Year Final Research Report Summary
Cell cycle and apoptosis in the process of carcinogenesis in oral precancerous lesions
| Project/Area Number |
08457554
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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 |
Surgical dentistry
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| Research Institution | Showa University |
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Principal Investigator |
NAGUMO Masao Showa university, School of Dentistry, Professor, 歯学部, 教授 (70013993)
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| Co-Investigator(Kenkyū-buntansha) |
KAMIJO Ryutaro Showa University, School of Dentistry, Assistant Professor, 歯学部, 講師 (70233939)
IWASA Masayasu Showa University, School of Dentistry, Assistant Professor, 歯学部, 講師 (50193743)
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| Project Period (FY) |
1996 – 1997
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| Keywords | oral leukoplakia / G1 cycline / cycline dependent kinase / cell cycle / p21 / waf1 / p53 knockout mouse / TUNEL method / apoptosis |
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| Research Abstract |
Expression of G1 cyclins, cyclin dependent kinases (CDK) and p21/waf1 was examined in oral leukoplakia (OLP) snd oral cancer tissue. In addition, growth activity and cell cycle of oral mucosal keratinocytes in p53 gene knockout mouse were also studied.
The results obtained were as follows :
1.Cyclin D1, cyclin E,CDK2 and CDK4 were weekly expressed in normal oral mucosal epithelium, whereas their expression in OLP became strong with the grade of epithelial dysplasia. Each positivity was significantly higher in OLP with moderate and severe epithelial dysplasia and oral cancer tissues than in normal oral mucosal epithelium.
2.p21/waf1 was not expressed in normal oral mucosal epithelium and oral cancer tissue, but it was found in OLP with moderate and severe epithelial dysplasia. However, p21/waf1 mRNA was expressed in all tissues.
3.TUNEL-positive cells were most frequently observed in normal oral mucosal epithelium. Decreasing tendency in TUNEL-positive cell rate was found with the grade of epithelial dysplasia and carcinogenesis.
4.Growth activity of oral mucosal keratinocytes in p53 knockout mouse was higher than that in normal (wild) mouse. The flowcytometric analysis revealed that the duration of G1 phase was shortened in p53 knockout mouse.
These results suggest that the misrule of cell cycle and suppression of apoptosis may be concerned in carcinogenesis of OLP.
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