ROLE OF PGE2 RECEPTORS EP2 AND EP3 ON SENESCENCE

PGE2 受体 EP2 和 EP3 对衰老的作用

• 批准号: 6196488
• 负责人: RAYMOND L KONGER
• 金额: $ 12.35万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-08-01 至 2005-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6196488
• 关键词: RNase protection assay; athymic mouse; biological signal transduction; cell cycle proteins; cell growth regulation; cell senescence; cyclic AMP; diacylglycerols; flow cytometry; gel electrophoresis; human tissue; immunocytochemistry; keratinocyte; metastasis; neoplasm /cancer invasiveness; prostaglandin E; prostaglandin receptor; protein kinase C; receptor expression; telomerase; tissue /cell culture; western blottings

Growth stimulation by EP2 receptors is dependent on ligand- dependent activation of adenylate cyclase, with elevation of cyclic adenosine monophosphate (cAMP). In keratinocytes, EP3 receptors are coupled to a delayed increase in diacylglycerol (DAG). Evidence suggests that growth regulation by these receptors is secondary to an opposing action on cellular senescence, with EP3 receptors stimulating cellular senescence and EP2 receptors blocking senescence. Escape from senescence is highly associated with cellular immortality in vitro and neoplastic growth in vivo. Senescence has been linked to decreased chromosomal replicative capacity secondary to loss of telomere length. Telomere length is maintained by the enzyme telomerase. Senescence-induced growth arrest is associated with loss of telomerase activity and upregulation of the cell cycle regulatory proteins, p21WAF1 and p16INK4A. Expression of p21WAF1, in turn, is associated with decreased telomerase activity. Decreased p16INK4A and p21WAF1 expression is routinely observed in cutaneous malignancy. Using biochemical, pharmacological, and molecular approaches, this proposal will examine a number of questions: 1. Using specific receptor agonists and cells transfected with EP3-sense and -antisense constructs, what are the proximate signaling pathways utilized by EP3 receptors? 2. By examining the expression of EP2 and EP3 receptors in normal, immortalized, and neoplastic kertinocyte cell lines, is loss of EP3, or gain of EP2, receptors associated with immortalization and neoplasia? 3. Using sense and antisense transfectants, as well as pharmacological interventions, how do EP2 and EP3 intracellular signaling pathways integrate with the expression of the key cell cycle proteins, p21WAF1, telomerase, and p161NK4A? 4. Does mutually inhibitory crosstalk between EP2 and EP3 receptor signaling account for their opposing activities on cellular senescence? 5. What affect does loss/gain of receptor expression have on the tumorigenicity, invasiveness, and metastatic potential of neoplastic human cell lines xenografted into nude mice? The proposed studies provide a model for examining the role of PGE2 in normal and neoplastic keratinocyte growth. More generally, these studies will define the role of cAMP- and DAG- intracellular signaling pathways in regulating cellular mortality. These studies will underscore how alterations of receptor expression serve to define the role of eicasonoids in diverse cellular functions.

EP2受体的生长刺激取决于腺苷酸环化酶的配体依赖性激活，并以环状腺苷单磷酸（CAMP）升高。 在角质形成细胞中，EP3受体与二酰基甘油（DAG）延迟增加。 证据表明，这些受体的生长调节是对细胞衰老的相反作用的继发性，而EP3受体刺激细胞衰老，EP2受体阻止衰老。 从衰老中逃脱与体内体外和肿瘤生长的细胞永生高度相关。 衰老与端粒长度损失继发的染色体复制能力降低有关。 端粒长度由酶端粒酶维持。 衰老引起的生长停滞与端粒酶活性的丧失以及细胞周期调节蛋白，p21WAF1和P16INK4A的上调有关。 p21WAF1的表达反过来与端粒酶活性降低有关。 在皮肤恶性肿瘤中常规观察到P16INK4A和P21WAF1表达降低。 使用生化，药理学和分子方法，该建议将检查许多问题：1。使用特定的受体激动剂和用EP3 -Sense和-antisensens构建体转染的特定受体激动剂，EP3受体使用的近端信号传导途径是什么？ 2。通过检查正常，永生和肿瘤的Kertinopyte细胞系中EP2和EP3受体的表达，是EP3的损失或EP2的增益与永生化和肿瘤有关的受体的增益吗？ 3。使用有义和反义转染剂以及药理学干预措施，EP2和EP3细胞内信号通路如何与钥匙细胞周期蛋白，p21WAF1，端粒酶和p161NK4A的表达相结合？ 4。EP2和EP3受体信号之间的相互抑制性串扰是否解释了它们在细胞衰老上的相对活性？ 5。受体表达的损失/增益对肿瘤性，侵袭性和转移性潜在的肿瘤性人体细胞系的转移潜力有什么影响？ 拟议的研究提供了一个模型，用于检查PGE2在正常和肿瘤角质形成细胞生长中的作用。 更普遍地，这些研究将定义cAMP和DAG-细胞内信号通路在调节细胞死亡率中的作用。 这些研究将强调受体表达的变化如何定义类花生素在各种细胞功能中的作用。