Regulation of prostate cancer cell survival by 5-lipoxygenase:Role of PKC-epsilon

5-脂氧合酶对前列腺癌细胞存活的调节：PKC-ε 的作用

基本信息

批准号：
8184483
负责人：
JAGADANANDA GHOSH
金额：
$ 24.32万
依托单位：
HENRY FORD HEALTH SYSTEM
依托单位国家：
美国
项目类别：
财政年份：
2011
资助国家：
美国
起止时间：
2011-09-12 至 2015-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8184483
关键词：
12-HETE Age Androgens Animal Model Animals Apoptosis Arachidonate 5-Lipoxygenase C57BL/6 Mouse Cancer Control Cell Fractionation Cell Survival Cells Chemicals DNA Binding Data Development Diazoxide Diet Disease Dominant-Negative Mutation Down-Regulation Epithelial Cells Gene Targeting Genetic Transcription Goals Growth Health Human Hydroxyeicosatetraenoic Acids Immunohistochemistry Induction of Apoptosis Knock-out Knockout Mice Leukotrienes Malignant Neoplasms Malignant neoplasm of prostate Measures Mediating Mediator of activation protein Mitochondria Mitosis Mus Nuclear Nude Mice Omega-6 Fatty Acids Oncogenic Oral Organelles Phosphorylation Play Prevention strategy Prevention therapy Preventive Production Prostate Prostatic Neoplasms Regulation Research Project Grants Resistance Role Series Signal Transduction Solvents Testing Therapeutic Time Toxic effect Transgenic Organisms Translations Tumor Tissue Up-Regulation Western Blotting Xenograft procedure androgen independent prostate cancer aurora kinase base cancer cell design in vivo inhibitor/antagonist killings male neoplastic cell novel novel strategies overexpression prevent promoter protein kinase C epsilon research study survivin treatment duration treatment effect tumor tumor growth tumor xenograft

项目摘要

DESCRIPTION (provided by applicant): Regulation of prostate cancer cell survival by 5-lipoxygenase: Role of PKC-epsilon Fresh experimental data suggest that induction of apoptosis in prostate cancer (PCa) cells by blocking critical survival mechanism(s) can be an attractive approach to prevent and treat PCa because clinically PCa is often characterized as slow growing where anti-mitogenic therapies are not much effective. However, the repertoire of survival mechanisms in PCa cells is not completely understood which largely contributes to the loss of battle against this disease. Emerging evidence from various studies has shown that PCa cells constitutively generate metabolites of 5-lipoxygenase (5-Lox) from arachidonic acid (an omega-6 fatty acid plentiful in Western diets), and inhibition of 5-Lox by specific inhibitors blocks production of 5-Lox metabolites and induces rapid apoptosis both in androgen-sensitive as well as androgen-independent PCa cells sparing non-cancer cells. Apoptosis is effectively prevented by the 5-Lox metabolites, 5(S)-HETE and 5-oxoETE, suggesting that these metabolites play an essential role in the survival of PCa cells. A critical role of 5-Lox in the survival of PCa cells has also been documented using siRNAs against 5-Lox. However, signaling mechanism(s) through which 5-Lox metabolites regulate PCa cell survival are not yet understood. Interestingly, 5-Lox is not expressed in normal prostate glands but is highly expressed in prostate tumors and in PCa cells, which together with a critical role of 5-Lox in the survival of PCa cells, suggests that 5-Lox may play an important role in the development of PCa. A recent pilot experiment showed that MK591, a specific inhibitor of 5-Lox activity, remarkably blocks prostate tumor growth in nude mice xenografts without any toxicity to animal health, suggesting that inhibition of 5-Lox could be an attractive approach for mounting specific attack on PCa cells without general toxicity. Thus, in vivo targeting of 5-Lox should be extensively carried out for a rapid translational development against PCa. The goals of this research project are to delineate the signaling mechanisms underlying regulation of PCa cell survival by 5-Lox, and to test the in vivo effects of targeting 5-Lox focusing on both the preventive and therapeutic aspects of PCa. These goals will be achieved by accomplishing the objectives of three specific aims. Specific Aim 1 will determine how 5-Lox activity regulates PCa cell survival involving PKC-epsilon (PKC5)-mediated signaling, because inhibition of 5-Lox inhibits PKC5 which is prevented by 5-Lox metabolites, and 5-Lox inhibition-induced apoptosis is prevented by activators of PKC5. Specific Aim 2 will determine whether inhibition of 5-Lox inhibits growth of prostate tumors in nude mice xenografts via induction of apoptosis in PCa cells. Specific Aim 3 will determine the role of 5-Lox in the development and progression of PCa by generating 5-Lox knockout transgenic (TRAMP) mice. Accomplishing the goals in this research project will help us to understand a novel mechanism of PCa cell survival, to determine whether 5-Lox plays a role in the development and progression of PCa, and to test whether targeting 5-Lox could be a novel mechanism-based strategy for prevention as well as treatment of PCa. PUBLIC HEALTH RELEVANCE: Regulation of prostate cancer cell survival by 5-lipoxygenase: Role of PKC-epsilon Emerging evidence from our own studies and others has shown that prostate cancer cells constitutively generate metabolites of 5-lipoxygenase (5-Lox) and inhibition of 5-Lox blocks the production of 5-Lox metabolites and induces rapid apoptosis both in androgen-sensitive as well as in androgen-independent prostate cancer cells sparing normal, non-cancer cells. Interestingly, it was observed that 5-Lox is not expressed in normal, non-cancer prostate glands, but is highly expressed in prostate tumor tissues and in cultured prostate cancer cells, suggesting that 5-Lox may play an important role in prostate cancer development. Thus, 5-Lox has emerged as an attractive, novel target for prostate cancer control. However, signaling mechanism(s) through which 5-Lox metabolites regulate prostate cancer cell survival are yet to be understood, and extensive in vivo testing of targeting 5-Lox are needed to develop novel strategies for prevention and therapy of prostate cancer. Our preliminary observations suggest that 5-Lox activity regulates protein kinase C-epsilon (PKC5) and PKC5 is a potential mediator of the survival-promoting effects of 5-Lox metabolites. Thus, this project has been designed to understand a novel mechanism of prostate cancer cell survival regulated by 5-Lox, and to test the in vivo effects of targeting 5-Lox by novel agents and strategies for prevention as well as treatment of prostate cancer.

描述（由申请人提供）：5-脂氧合酶对前列腺癌细胞存活的调节：PKC-ε的作用新的实验数据表明，通过阻断关键存活机制来诱导前列腺癌（PCa）细胞凋亡可能是一种有吸引力的方法。预防和治疗 PCa 的方法，因为临床上 PCa 的特点是生长缓慢，抗有丝分裂疗法效果不佳。然而，PCa 细胞的全部生存机制尚未完全了解，这在很大程度上导致了与这种疾病的斗争的失败。各种研究的新证据表明，PCa 细胞从花生四烯酸（西方饮食中富含的 omega-6 脂肪酸）组成性地产生 5-脂氧合酶 (5-Lox) 代谢物，并且通过特定抑制剂抑制 5-Lox 会阻止 5-Lox 的产生。 5-Lox 在雄激素敏感型和雄激素非依赖性 PCa 细胞中代谢并诱导快速凋亡，而不影响非癌细胞。 5-Lox 代谢物 5(S)-HETE 和 5-oxoETE 可有效防止细胞凋亡，表明这些代谢物在 PCa 细胞的存活中发挥重要作用。使用针对 5-Lox 的 siRNA 也证明了 5-Lox 在 PCa 细胞存活中的关键作用。然而，5-Lox 代谢物调节 PCa 细胞存活的信号传导机制尚不清楚。有趣的是，5-Lox 在正常前列腺中不表达，但在前列腺肿瘤和 PCa 细胞中高表达，这与 5-Lox 在 PCa 细胞存活中的关键作用一起表明 5-Lox 可能发挥重要作用PCa 发展中的作用。最近的一项初步实验表明，MK591（一种 5-Lox 活性的特异性抑制剂）可显着阻止裸鼠异种移植物中前列腺肿瘤的生长，且对动物健康没有任何毒性，这表明抑制 5-Lox 可能是对前列腺癌进行特异性攻击的一种有吸引力的方法。 PCa细胞无一般毒性。因此，应广泛开展 5-Lox 的体内靶向研究，以实现针对 PCa 的快速转化开发。该研究项目的目标是描绘 5-Lox 调节 PCa 细胞存活的信号传导机制，并测试靶向 5-Lox 的体内效果，重点关注 PCa 的预防和治疗方面。这些目标将通过实现三个具体目标来实现。具体目标 1 将确定 5-Lox 活性如何调节涉及 PKC-epsilon (PKC5) 介导的信号传导的 PCa 细胞存活，因为抑制 5-Lox 会抑制 PKC5，而 PKC5 会被 5-Lox 代谢物阻止，并且 5-Lox 抑制会诱导细胞凋亡被 PKC5 激活剂阻止。具体目标 2 将确定抑制 5-Lox 是否会通过诱导 PCa 细胞凋亡来抑制裸鼠异种移植物中前列腺肿瘤的生长。具体目标 3 将通过生成 5-Lox 敲除转基因 (TRAMP) 小鼠来确定 5-Lox 在 PCa 发生和进展中的作用。完成本研究项目的目标将有助于我们了解 PCa 细胞存活的新机制，确定 5-Lox 是否在 PCa 的发生和进展中发挥作用，并测试靶向 5-Lox 是否可能是一种新机制基于 PCa 的预防和治疗策略。公共健康相关性： 5-脂氧合酶对前列腺癌细胞存活的调节：PKC-ε 的作用我们自己和其他人的研究的新证据表明，前列腺癌细胞持续产生 5-脂氧合酶 (5-Lox) 代谢物并抑制 5-脂氧合酶 (5-Lox) 的代谢产物。 -Lox 阻断 5-Lox 代谢物的产生，并在雄激素敏感和雄激素非依赖性前列腺中诱导快速细胞凋亡癌细胞不伤害正常的非癌细胞。有趣的是，据观察，5-Lox 在正常的非癌症前列腺中不表达，但在前列腺肿瘤组织和培养的前列腺癌细胞中高表达，这表明 5-Lox 可能在前列腺癌的发展中发挥重要作用。因此，5-Lox 已成为前列腺癌控制的一个有吸引力的新靶点。然而，5-Lox 代谢物调节前列腺癌细胞存活的信号传导机制尚待了解，并且需要针对 5-Lox 进行广泛的体内测试，以开发预防和治疗前列腺癌的新策略。我们的初步观察表明，5-Lox 活性调节蛋白激酶 C-epsilon (PKC5)，并且 PKC5 是 5-Lox 代谢物的生存促进作用的潜在介质。因此，该项目旨在了解5-Lox调节的前列腺癌细胞存活的新机制，并测试通过预防和治疗前列腺癌的新药物和策略靶向5-Lox的体内效果。