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Chemopreventive Properties of Black Raspberries in N-Nitrosomethylbenzylamine-Induced Rat Esophageal Tumorigenesis: Down-regulation of Cyclooxygenase-2, Inducible Nitric Oxide Synthase, and c-Jun

kane35 添加于 2010-8-7 10:43 | 1887 次阅读 | 0 个评论

作者
Chen T
摘要
Our laboratory has used a rodent model of human esophageal squamous cell carcinoma to identify putative chemopreventive agents for this disease and to determine their mechanisms of action. In the present study, we treated F344 rats with the esophageal carcinogen, N-nitrosomethylbenzylamine (NMBA), thrice per week for 5 weeks. Beginning 1 week later, they were fed a synthetic diet containing 5% black raspberries (BRB) for the duration of the bioassay (25 weeks). Rats were sacrificed at weeks 9, 15, and 25. Esophageal tissues were collected, and tumor data were recorded. The expression and enzymatic activities of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) as well as the expression of c-Jun in the esophagi, were evaluated to investigate the mechanism(s) by which black raspberries modulate tumorigenesis. At week 25, BRB inhibited tumor multiplicity, the standard end point in this tumor model, from 3.78 F 0.41 tumors per rat in NMBAtreated animals to 2.23 F 0.21 tumors per rat in animals treated with NMBA plus BRB (P < 0.005). BRB reduced mRNA and protein expression levels of COX-2, iNOS, and c-Jun as well as the level of prostaglandin E2 in preneoplastic lesions of the esophagus at week 25. The berries inhibited mRNA expression of iNOS and c-Jun, but not COX-2, in papillomatous lesions of the esophagus. Prostaglandin E2 and total nitrite levels were also decreased by BRB in papillomas. These results suggest a novel tumor suppressive role of BRB through inhibition of COX-2, iNOS, and c-Jun.
详细资料
- 文献种类:期刊
- 期刊名称: Cancer Research
- 期刊缩写: Cancer Research
- 期卷页: 2006年第66卷第5期 2853-2859页
- ISBN: 0008-5472
标签

chemopreventive
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