Novel Insights in the regulation of HIF1alpha Stability

HIF1alpha 稳定性调节的新见解

• 批准号: 7988247
• 负责人: Ze'ev A Ronai
• 金额: $ 38.24万
• 依托单位: SANFORD BURNHAM PREBYS MEDICAL DISCOVERY INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-30 至 2015-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7988247
• 关键词: Adenocarcinoma Cell; Androgens; Attenuated; CWR22Rv1; Cells; Complex; Development; Employee Strikes; Exhibits; Foundations; Gene Expression; Genes; Genetic Transcription; Goals; Grant; Human; Human Development; Hypoxia; In Vitro; LNCaP; Malignant neoplasm of prostate; Modeling; Monitor; Mus; Neoplasm Metastasis; Neuroendocrine Carcinoma; Neuroendocrine Tumors; Neurosecretory Systems; Output; Peptides; Phenotype; Physiological; Play; Primary Neoplasm; Prostate Adenocarcinoma; Prostate Neuroendocrine Neoplasm; Prostatic Neoplasms; Regulation; Regulatory Pathway; Role; Testing; Transcriptional Activation; Ubiquitination; Xenograft Model; Xenograft procedure; base; cancer cell; hypoxia inducible factor 1; in vivo; inhibitor/antagonist; insight; interest; neoplastic cell; novel; outcome forecast; promoter; public health relevance; transcription factor; tumor; tumorigenesis; ubiquitin ligase

DESCRIPTION (provided by applicant): Neuroendocrine (NE) carcinoma and NE differentiation (NED), which occur in 30% of human prostate tumors, are hallmarks of aggressive human prostate cancer. The goal of this application is to extend our exciting findings that reveal a novel mechanism underlying development of prostate NE tumors. This discovery originated from our observation that NE tumors, which form in the TRAMP mouse prostate tumor model, are no longer seen when these mice are crossed with the ubiquitin ligase Siah2 KO mice. This striking result led us to hypothesize that Siah2 activity underlies NE prostate tumor development. Earlier studies supported by this grant identified a role for Siah2 in increasing HIF-11 stability (through ubiquitination and degradation of prolyl hydroxylase1/3 stability). Therefore, observing a loss of NE tumors led us to explore a causative role for Siah2/HIF-1? in NE phenotype and prostate tumor development. Indeed, mice lacking Siah2 exhibited markedly reduced levels of HIF-1? expression. To understand how lower levels of HIF-1? could antagonize NE tumor development we assessed potential HIF-1? cooperation with FoxA2, a transcription factor functioning in prostate tumor development and associated with NE differentiation. Co-expression with FoxA2 markedly increased HIF?'s ability to transactivate HRE-based promoters. Further, we identified a subset of genes regulated by FoxA2/HIF-1? including Hes6, Jmjd1a, Plod2 and Sox9. Of particular significance is that we have confirmed the expression of these select subsets in mouse NE tumors but also in metastatic human prostate adenocarcinoma. Furthermore, co-expression of these genes rescued formation of NE phenotype in human prostate tumor cells expressing Siah2 inhibitor, as well as the ability of these cells to form prostate tumors in mouse xenograft. Overall, these findings led to our hypothesis that Siah2-dependent concerted activity of HIF-1? and FoxA2 plays a central role in formation of NE phenotypes and development of human prostate tumors. We thus propose to identify mechanisms underlying FoxA2 and HIF cooperation and their contribution to NE phenotype and human prostate tumor development. We will therefore (1) determine the role of FoxA2, HIF-1? and Siah in androgen-dependent and -independent human prostate adenocarcinoma development and progression, and in NE phenotype; (2) characterize mechanisms underlying FoxA2 cooperation with HIF-1?; (3) determine the role of select HIF-1?/FoxA2 regulated genes - Hes6, Plod2, Sox9 and Jmjd1a - in prostate tumor development and progression and assess the possible use of these genes as markers for human prostate adenocarcinomas; and (4) identify key domains required for FoxA2 association and cooperation with HIF-1? to determine whether inhibiting FoxA2/HIF-1? cooperation by use of select peptides blocks formation of human NE prostate tumors in mouse xenograft models. Our proposed studies are expected to establish a new regulatory pathway in NE phenotype and prostate tumor development and metastasis. PUBLIC HEALTH RELEVANCE: Our proposed studies will characterize a novel regulatory pathway involving a ubiquitin ligase and transcription complex which is found to a play central role in human prostate tumor development and progression, with an emphasis on the one bearing a neuroendocrine phenotype. Since neuroendocrine involvement is found in 30% of human prostate adenocarcinomas and is associated with poor prognosis, our proposed studies offer novel mechanisms underlying the more aggressive form of human prostate tumor, with possible implications for targeted therapy and monitoring.

描述（由申请人提供）：在30％的人类前列腺肿瘤中发生的神经内分泌（NE）癌（NE）癌（NED）是侵略性人类前列腺癌的标志。该应用的目的是扩展我们令人兴奋的发现，该发现揭示了前列腺NE肿瘤发展的新机制。这一发现源于我们的观察结果，即在流浪小鼠前列腺肿瘤模型中形成的NE肿瘤不再被视为当这些小鼠与泛素连接酶SIAH2 KO小鼠交叉时。这种惊人的结果使我们假设SIAH2活性是前列腺肿瘤发展的基础。该赠款支持的早期研究确定了SIAH2在提高HIF-11稳定性方面的作用（通过泛素化和降解丙酰羟化酶1/3稳定性）。因此，观察NE肿瘤的损失使我们探索了SIAH2/HIF-1的致病作用？在NE表型和前列腺肿瘤发育中。确实，缺乏SIAH2的小鼠表现出明显降低的HIF-1水平？表达。了解HIF-1级别的水平如何？我们可以评估潜在的HIF-1的NE肿瘤发展吗？与FOXA2的合作，FOXA2是一种在前列腺肿瘤发育中起作用的转录因子，与NE分化有关。与FOXA2的共表达显着提高了HIF？具有基于HRE的启动子的反式激活能力。此外，我们确定了由FOXA2/HIF-1调节的基因的子集？包括HES6，JMJD1A，PLOD2和SOX9。特别重要的是，我们已经证实了这些精选亚群在小鼠NE肿瘤中的表达，也证实了在转移性人类前列腺腺癌中的表达。此外，这些基因的共表达挽救了表达SIAH2抑制剂的人前列腺肿瘤细胞中NE表型的形成，以及这些细胞在小鼠异种移植物中形成前列腺肿瘤的能力。总体而言，这些发现导致了我们的假设，即HIF-1的SIAH2依赖性协同活动？ FOXA2在形成NE表型和人类前列腺肿瘤的发展中起着核心作用。因此，我们建议确定FOXA2和HIF合作的基础机制及其对NE表型和人类前列腺肿瘤发展的贡献。因此，我们将（1）确定FOXA2，HIF-1的作用？和SIAH在雄激素依赖性和独立的人前列腺腺癌发育和进展以及NE表型中； （2）表征与HIF-1合作的基础机制？ （3）确定选择的HIF -1？/FOXA2调控基因的作用-HS6，PLOD2，SOX9和JMJD1A-在前列腺肿瘤发育和进展中的作用，并评估这些基因作为人前列腺腺癌的标志物的可能使用； （4）确定FOXA2关联所需的关键领域并与HIF-1合作？确定是否抑制FOXA2/HIF-1？通过使用精选肽阻止小鼠异种移植模型中人NE前列腺肿瘤的形成的合作。我们提出的研究有望在NE表型和前列腺肿瘤发育和转移中建立新的调节途径。 公共卫生相关性：我们的拟议研究将表征涉及泛素连接酶和转录复合物的新型调节途径，该途径在人类前列腺肿瘤的发展和进展中起着重要的核心作用，重点是具有神经内脏的表型。由于神经内分泌的参与是在30％的人类前列腺腺癌中发现的，并且与预后不良有关，因此我们提出的研究提供了更具侵略性的人类前列腺肿瘤形式的新机制，对靶向治疗和监测可能影响。