Role of Cyclooxygenase-2 on development and progression of colorectal cancer and its chemopreventive effect.
Project/Area Number |
14570494
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Single-year Grants |
Section | 一般 |
Research Field |
Gastroenterology
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Research Institution | Kyoto Prefectural University of Medicine |
Principal Investigator |
KONISHI Hideyuki KYOTO PREFECTURAL UNIVERSITY OF MEDICINE, GRADUATE SCHOOL OF MEDICAL SCIENCES MOLECULAR GASTROENTEROLOGY, INSTRUCTOR, 医学研究科, 助手 (30295670)
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Co-Investigator(Kenkyū-buntansha) |
NODA Masao KYOTO PREFECTURAL UNIVERSITY OF MEDICINE, GRADUATE SCHOOL OF MEDICAL SCIENCES, MOLECULAR GASTROENTEROLOGY, INSTRUCTOR, 医学研究科, 助手 (70326221)
|
Project Period (FY) |
2002 – 2004
|
Project Status |
Completed (Fiscal Year 2004)
|
Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 2004: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2003: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 2002: ¥900,000 (Direct Cost: ¥900,000)
|
Keywords | COLORECTAL TUMOR / CYCLOOXYGENASE-2 / CHEMOPREVENTION |
Research Abstract |
Although accumulated knowledge has shown that cyclooxygenase-2(COX-2) plays an important role in the occurrence and the progression of colorectal tumor, the mechanism how COX-2 promotes colorectal tumorigenesis remains unclear. One intriguing finding is that the expression of COX-2 impairs the apoptotic response. In this study we investigated when COX-2 protein starts to overexpress in colorectal tumors in the process of developing cancer from adenoma and whether COX-2 expression correlates with proliferation and/or apoptosis in human sporadic colorectal cancers. MATERIALS & METHODS : A retrospective review of patients with early colorectal tumor was performed. Immunohistochemical analysis was performed on paraffin-embedded tissue samples using a COX-2 antibody. Proliferation and apoptosis were investigated on serial sections by Ki-67 antibody and TUNEL method as well as p53 immunohistochemistry. COX-2 score, Ki-67 labeling index, apoptotic index and p53-positive ratio were calculated
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at both surface and deeper parts of the tumor. The relationship between Ki-67 labeling index or apoptotic index, p53-positive ratio and COX-2 score at each part of the tumor was analyzed. RESULTS : In colorectal tumors, marked expression of immunoreactive COX-2 was present not only in interstitial cells including inflammatory mononuclear cells, vascular endothelial cells and fibroblasts, but also in tumor cells. In proportion as the tumor increased in size, COX-2 positive ratio increased. The COX-2 score and p53 positive ratio at deeper part of cancers were higher than those at surface part. Ki-67 labeling index at deeper part was significantly lower than that at surface part. At surface part the COX-2 score of p53-positive cancers was higher than that of p53-negative cancers. The apoptotic index showed no correlation with COX-2 score. At deeper part, on the other hand, lower apoptotic index correlated with higher COX-2 score. The Ki-67 labeling index and p53 positive ratio showed no correlation with COX-2 score. The apoptotic index of p53-positive cancers was significantly lower than that of p53-negative cancers at both surface and deeper parts. CONCLUSIONS : These evidences support the hypothesis that COX-2 promotes development of colorectal tumors, one of which mechanisms is to prevent apoptosis with p53-independent pathway. Less
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Report
(4 results)
Research Products
(11 results)