Inhibition of UVB-induced COX-2 expression by apigenin

芹菜素抑制 UVB 诱导的 COX-2 表达

基本信息

批准号：
7247179
负责人：
JILL C. PELLING
金额：
$ 27.36万
依托单位：
NORTHWESTERN UNIVERSITY AT CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2004
资助国家：
美国
起止时间：
2004-09-01 至 2009-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7247179
关键词：
3&apos Untranslated Regions Affect Apigenin Binding Binding Sites Bioflavonoid Biological Assay Boxing CCAAT-Enhancer-Binding Protein-beta Chemopreventive Agent Coxibs DNA-Binding Proteins Dinoprostone Epidermis Genetic Transcription Inbred HRS Mice Investigation Knockout Mice Laboratories Longitudinal Studies Luciferases Messenger RNA Molecular Mechanisms of Action Mus Northern Blotting Pathway interactions Post-Transcriptional Regulation Prevention Production Promoter Regions Proteins Reporter Reporting Research Research Personnel Response Elements Role Site Skin Skin Cancer Skin Carcinogenesis Suggestion Testing Topical application Trans-Activators Transfection UV induced UVB induced Western Blotting base cyclooxygenase 1 cyclooxygenase 2 in vivo inhibitor/antagonist keratinocyte mRNA Stability novel strategies promoter research study transcription factor tumorigenesis ultraviolet irradiation

项目摘要

DESCRIPTION (provided by applicant): Apigenin is a nonmutagenic bioflavonoid that inhibits UV-induced skin cancer when topically applied to mouse skin and we are currently investigating its molecular mechanism(s) of action. Recent results from our laboratory indicate that inhibition of the cyclooxygenase-2 (COX-2) pathway is one of the ways that apigenin exerts its chemopreventive effect. We have demonstrated that apigenin is a specific inhibitor of UV-induced cyclooxygenase-2 (COX-2) transcription in UV-induced keratinocytes. We have also obtained new evidence since the previous submission that UV-induction of COX-2 expression in keratinocytes requires the E-box and ATF/CRE transcription factor binding sites in the first 200 bases of the COX-2 promoter region, as well as demonstrating a role for the NF-IL6 site. These results suggest that one mechanism by which apigenin inhibits UV-induced skin carcinogenesis is by modulating the function of DNA binding proteins specific for these sites. Recent reports from other laboratories including our collaborator Dr. Aubrey Morrison indicate that COX-2 expression is regulated post-transcriptionally as well, by trans-acting factors which affect COX-2 mRNA stability and modulate translational efficiency. Therefore the hypothesis to be tested in this revised application is that one of the mechanisms by which the bioflavonoid apigenin inhibits UV-induced skin carcinogenesis is through modulation of transcriptional and post-transcriptional control of COX-2 expression. The following aims will test this hypothesis: In Aim #1we will continue our efforts to identify the DNA binding proteins in the COX-2 promoter required for UVB-induced COX-2 transcription and for inhibition by apigenin in keratinocytes and mouse epidermis in vivo. In Aim #2 we will investigate the mechanism by which apigenin treatment of keratinocytes modulates the function of the DNA binding proteins identified in Aim #1. In Aim #3 we will characterize the post-transcriptional control mechanisms which affect UVB-induced COX-2 expression in keratinocytes treated with apigenin, using regions of the COX-2 3'-UTR to investigate apigenin's ability to interfere with UV-induced mRNA stabilization and/or translational efficiency. In Aim #4 we will use SKH-1 mice and SKH-1 COX-2 null mice to confirm the ability of apigenin to block UVB-induced COX-2 expression and tumorigenesis in vivo.

描述（由申请人提供）：芹菜素是一种非诱变生物类黄酮，局部应用于小鼠皮肤时可抑制紫外线诱发的皮肤癌，我们目前正在研究其作用的分子机制。我们实验室的最新结果表明，抑制环氧合酶-2 (COX-2) 途径是芹菜素发挥其化学预防作用的方式之一。我们已经证明芹菜素是紫外线诱导的角质形成细胞中紫外线诱导的环氧合酶-2 (COX-2) 转录的特异性抑制剂。自上次提交以来，我们还获得了新的证据，表明角质形成细胞中 COX-2 表达的紫外线诱导需要 COX-2 启动子区域前 200 个碱基中的 E-box 和 ATF/CRE 转录因子结合位点，以及展示 NF-IL6 位点的作用。这些结果表明芹菜素抑制紫外线诱导的皮肤癌发生的一种机制是通过调节这些位点特异的 DNA 结合蛋白的功能。其他实验室（包括我们的合作者 Aubrey Morrison 博士）最近的报告表明，COX-2 表达也受到转录后调节，通过反式作用因子影响 COX-2 mRNA 稳定性并调节翻译效率。因此，在该修订的申请中要测试的假设是生物类黄酮芹菜素抑制紫外线诱导的皮肤癌发生的机制之一是通过调节COX-2表达的转录和转录后控制。以下目标将检验这一假设：在目标 1 中，我们将继续努力鉴定 COX-2 启动子中的 DNA 结合蛋白，这些蛋白是 UVB 诱导的 COX-2 转录以及体内角质形成细胞和小鼠表皮中芹菜素抑制所需的。在目标#2 中，我们将研究芹菜素处理角质形成细胞调节目标#1 中确定的 DNA 结合蛋白功能的机制。在目标#3中，我们将描述影响用芹菜素处理的角质形成细胞中UVB诱导的COX-2表达的转录后控制机制，使用COX-2 3'-UTR区域来研究芹菜素干扰UV诱导的mRNA的能力稳定性和/或转化效率。在目标 #4 中，我们将使用 SKH-1 小鼠和 SKH-1 COX-2 null 小鼠来确认芹菜素阻断 UVB 诱导的 COX-2 表达和体内肿瘤发生的能力。