Imaging Cox-2 Gene Expression in Inflammation and Tumors

炎症和肿瘤中 Cox-2 基因表达的成像

• 批准号: 7048731
• 负责人: Harvey R. Herschman
• 金额: $ 32.83万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-12-17 至 2010-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7048731
• 关键词: bioimaging /biomedical imaging; biomarker; carcinogenesis; cutaneous papilloma; disease /disorder model; dopamine receptor; embryonic stem cell; fluorine; ganciclovir; gene expression; gene targeting; genetically modified animals; herpes simplex virus 1; image processing; inflammation; intestine neoplasm; laboratory mouse; neoplasm /cancer genetics; neoplastic process; positron emission tomography; prostaglandin endoperoxide synthase; prostaglandins; radionuclides; reporter genes; transfection /expression vector

DESCRIPTION (provided by applicant): Prostaglandins (PCs) play a role in a variety of physiological functions; e.g. immune responses, platelet aggregation, reproduction, respiratory function, thermoregulation. Exaggerated production often occurs in pain, fever, chronic/acute inflammation and cancer. The common intermediate in prostanoid production, PGH2, is produced from arachidonic acid by the cyclooxygenases (COXs). There are two cyclooxygenases, COX-1 and COX-2. COX-1 is usually expressed constitutively; COX-2 is induced by many stimuli. Non-steroidal anti-inflammatory drugs (NSAIDs) are analgesic, anti-pyretic and anti-inflammatory. They exert nearly all their biological actions by inhibiting COX activity. Discovery of COX-2 lead to development of the coxibs (e.g., Celebrex and Vioxx), which selectively inhibit COX-2. COX-2 expression - and prostaglandin production - is elevated in neurological degenerative diseases, in inflammatory conditions and in many cancers. Consequently, regulation of COX-2 expression is an extraordinarily active and important area of molecular, cellular and organismal research. We have created an heterozygous mouse in which the coding region of the firefly luciferase bioluminescence reporter gene has been "knock-into" one allele of the COX-2 gene at the ATG start site of translation. Thus one chromosome of this mouse expresses the COX-2 protein from one endogenous COX-2 regulatory regjon and the other chromosome expresses luciferase from the other endogenous COX-2 regulatory region. We will use this genetically modified mouse to non-invasively and repeatedly monitor COX-2 transcriptional activation in four inflammatory models (paw, air pouch, skin and lung) and in initiation, progression, metastasis and response to therapy of skin and colon cancer models. More recently it has become clear that regulation of COX-2 mRNA stability, modulated by the 3' untranslated region (3'UTR) of the COX-2 message, also plays a major role in regulating COX-2 levels in inflammatory responses and cancer. We will develop methods to non-invasively and repeatedly measure, in living mice, the effects of inflammatory stimuli and tumor initiation/progression on COX-2 mRNA stability. The ability to monitor, non-invasively and repeatedly, both COX-2 transcriptional activation and COX-2 mRNA stabilization will provide new insights into mechanisms of inflammation, tumor progression and neurological diseases as well as tools to monitor alternative therapies for these pathophysiologies. We will also create a transgenic mouse in which a fusion protein of the firefly luciferase optical imaging reporter and the HSVI-thymidine kinase PET reporter can be conditionally expressed as a result of Cre recombinase activation. Studies with this mouse will correlate optical and microPET imaging technologies.

描述（由申请人提供）：前列腺素（PC）在多种生理功能中发挥作用;例如免疫应答、血小板聚集、生殖、呼吸功能、体温调节。夸大的生产往往发生在疼痛，发烧，慢性/急性炎症和癌症。前列腺素类产生中的常见中间体PGH 2由花生四烯酸通过环加氧酶（COX）产生。存在两种环氧合酶，考克斯-1和考克斯-2。考克斯-1通常组成型表达，考克斯-2受多种刺激诱导。非甾体抗炎药（NSAIDs）具有镇痛、解热和抗炎作用。它们通过抑制考克斯活性发挥几乎所有的生物学作用。考克斯-2的发现导致了昔布类药物的开发（例如，西乐葆和万络），其选择性地抑制考克斯-2。考克斯-2的表达和前列腺素的产生在神经退行性疾病、炎症和许多癌症中升高。因此，考克斯-2表达的调控是分子、细胞和生物学研究中非常活跃和重要的领域。 我们已经创建了一个杂合子小鼠，其中萤火虫荧光素酶生物发光报告基因的编码区已被“敲入”的一个等位基因的考克斯-2基因的ATG翻译起始位点。因此，该小鼠的一条染色体从一个内源性考克斯-2调节区表达考克斯-2蛋白，另一条染色体从另一个内源性考克斯-2调节区表达荧光素酶。我们将使用这种基因修饰的小鼠来非侵入性地和重复地监测考克斯-2在四种炎症模型（爪子、气囊、皮肤和肺）中的转录激活以及在皮肤和结肠癌模型的起始、进展、转移和对治疗的响应中的转录激活。 最近已经清楚，由考克斯-2信息的3'非翻译区（3' UTR）调节的考克斯-2 mRNA稳定性的调节在炎症反应和癌症中调节考克斯-2水平中也起主要作用。我们将开发非侵入性和重复测量的方法，在活的小鼠中，炎症刺激和肿瘤起始/进展对考克斯-2 mRNA稳定性的影响。非侵入性和重复监测考克斯-2转录激活和考克斯-2 mRNA稳定的能力将为炎症、肿瘤进展和神经系统疾病的机制以及监测这些病理生理学的替代疗法提供新的见解。 我们还将创建一个转基因小鼠，其中萤火虫荧光素酶光学成像报告和HSV-胸苷激酶PET报告的融合蛋白可以有条件地表达作为Cre重组酶激活的结果。使用这种小鼠的研究将使光学和microPET成像技术相关联。