Amplification of tumor hypoxic responses by MIF-dependent HIF stabilization

MIF 依赖性 HIF 稳定作用放大肿瘤缺氧反应

基本信息

批准号：
8033184
负责人：
ROBERT A MITCHELL
金额：
$ 29.79万
依托单位：
UNIVERSITY OF LOUISVILLE
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-05-01 至 2014-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8033184
关键词：
Ablation Adenocarcinoma Cell Apoptosis Binding Biochemical COPS5 gene Cancer Patient Cell Line Cells Complement Complex Cullin Proteins Data Development Disease Progression Exhibits Fibrinogen Functional disorder Gene Targeting Genetic Genetic Transcription Growth Growth Factor Health Human Hypoxia Hypoxia Inducible Factor Image Immigration In Situ Nick-End Labeling In Vitro Injection of therapeutic agent Laboratories Lesion Maintenance Malignant Neoplasms Malignant neoplasm of pancreas Masks Mediating Metabolic Migration Inhibitory Factor Molecular Mus Mutant Strains Mice Neoplasm Metastasis Nude Mice Oxygen Oxygen measurement, partial pressure, arterial PECAM1 gene Pancreatic Adenocarcinoma Pancreatic Ductal Adenocarcinoma Pathology Pathway interactions Patients Pimonidazole Plasma Post-Translational Protein Processing Proteins Relative (related person)Resistance Role SLC2A1 gene Signal Transduction Small Interfering RNA Solid Neoplasm Staining method Stains Subgroup Therapeutic Transgenes Transgenic Mice Tumor Burden Vascular Endothelial Growth Factors Work Xenograft procedure angiogenesis bHLH-PAS factor HLF base cell motility cytokine density environmental adaptation extracellular fibroblast migration inhibitory factor human cancer mouse model hypoxia inducible factor 1 in vivo inhibitor/antagonist mouse model neovascularization novel outcome forecast overexpression pancreatic cancer cells pancreatic neoplasm phenylpyruvate tautomerase prevent protein degradation response transcription factor tumor tumor progression tumor xenograft tumorigenesis ubiquitin ligase ubiquitin-protein ligase

项目摘要

DESCRIPTION (provided by applicant): Pancreatic ductal adenocarcinoma (PDAC) has the grim distinction of being one of the most prognostically unfavorable human cancers. It has been suggested that low oxygen tensions within PDAC tumors contribute significantly to its metastatic potential and chemotherapeutic resistance. Hypoxia-inducible factors (HIFs) transcribe gene products that contribute to metabolic adaptation, neo-angiogenic potential, metastatic spread and therapeutic resistance. We recently discovered that macrophage migration inhibitory factor (MIF), one of the oldest cytokines ever described, is elevated in PDAC patient's plasma and induced by hypoxia-induced, HIF-1a-dependent transcription in pancreatic cancer cells. Intriguingly, MIF was found to reciprocally modulate hypoxia- induced HIF-1a stabilization. Several human PDAC cell lines transfected with siRNA against MIF recapitulate MIF-/- fibroblasts in defective hypoxia-induced HIF-1a stabilization and subsequent HIF-dependent transcription. Moreover, MIF-deficient PDAC cells display defective xenograft tumor outgrowth, less HIF-1a and significantly reduced microvascular density than MIF-containing xenografts. Finally, our results indicate that MIF promotes HIF-1a stability by functionally regulating a subunit of the COP9 signalosome, CSN5, in repressing a unique, HIF-1-specific ubiquitin E3 ligase. Our central hypothesis is that MIF overexpression in pancreatic adenocarcinoma lesions acts to modulate either the levels or activity of free CSN5 that, in turn, serves to repress or mask a unique, oxygen-independent ubiquitin E3 ligase specific for HIF-1a. Studies outlined in this application seek to identify the contribution and requirements for MIF in PDAC growth, pathophysiology and hypoxic adaptation. We will additionally delineate the precise mechanisms and molecular determinants involved in MIF-dependent HIF-1 stabilization. In order to fulfill the stated objectives of this application the following experimental aims are proposed: 1) Elucidate the basic mechanism by which MIF contributes to hypoxia-induced HIF-1a stabilization, 2) Define the molecular determinants and effectors of HIF-1 degradation in MIF-deficient cells, and 3) Determine if MIF contributes to pancreatic ductal adenocarcinoma growth, pathophysiology and hypoxic adaptation. PUBLIC HEALTH RELEVANCE: All solid tumors require microenvironmental adaptation throughout tumorigenesis. One of the hallmarks of this adaptive response is the development of intratumoral hypoxia that stimulates HIF-directed expression of pro-angiogenic/metastatic gene products. Our findings establish that one of these gene products, MIF, is elevated in the plasma of a subset of pancreatic cancer patients. We further describe a unique functional inter-relationship between the extracellular cytokine/growth factor MIF and the transcription factor, HIF-1a in pancreatic ductal adenocarcinoma (PDAC) cells. This point is demonstrated by our data showing that cells lacking MIF exhibit defective hypoxia and PHD inhibitor-induced HIF-1a stabilization and subsequent transcription of metabolic and angiogenic gene products. More importantly, xenograft mouse models of PDAC tumorigenesis reveal that MIF-deficient tumor outgrowth, HIF-1a expression and tumor-associated angiogenesis are severely impaired when compared to cells containing MIF. Because HIF expression contributes directly to tumor aggressiveness and cancers of the pancreas are reportedly very hypoxic, it is likely that MIF functionally contributes to tumor maintenance, environmental adaptation and ultimately prognosis of pancreatic adenocarcinoma patients.

描述（由申请人提供）：胰腺导管腺癌（PDAC）具有严峻的区别，即人的预后不利的人类癌症之一。有人提出，PDAC肿瘤内的低氧张力显着促进其转移性潜力和化学治疗性。低氧诱导因子（HIF）转录基因产物，有助于代谢适应，新血管生成潜力，转移性扩散和治疗性抗性。我们最近发现，巨噬细胞迁移抑制因子（MIF）是有史以来描述的最古老的细胞因子之一，在PDAC患者的血浆中升高，并由缺氧诱导的胰腺癌细胞中缺氧诱导的HIF-1A依赖性转录诱导。有趣的是，发现MIF会相互调节缺氧诱导的HIF-1A稳定。用siRNA转染MIF的几种人PDAC细胞系在缺陷缺氧诱导的HIF-1A稳定性和随后的HIF依赖性转录中概括了MIF - / - 成纤维细胞。此外，与含MIF的异种移植物相比，缺乏MIF的PDAC细胞表现出有缺陷的异种移植肿瘤生长，HIF-1A较少，显着降低了微血管密度。最后，我们的结果表明，MIF通过在抑制独特的HIF-1特异性泛素E3连接酶时通过功能调节COP9信号体CSN5的亚基来促进HIF-1A稳定性。我们的中心假设是，胰腺腺癌病变中的MIF过表达起作用可调节自由CSN5的水平或活性，而自由CSN5的水平或活性反过来又有助于抑制或掩盖独特的，独立于氧气的泛素泛蛋白E3 rigase e3 hifase for HIF-1A。该应用中概述的研究旨在确定MIF在PDAC生长，病理生理学和低氧适应性中的贡献和要求。我们还将描述参与MIF依赖性HIF-1稳定的精确机制和分子决定因素。 In order to fulfill the stated objectives of this application the following experimental aims are proposed: 1) Elucidate the basic mechanism by which MIF contributes to hypoxia-induced HIF-1a stabilization, 2) Define the molecular determinants and effectors of HIF-1 degradation in MIF-deficient cells, and 3) Determine if MIF contributes to pancreatic ductal adenocarcinoma growth, pathophysiology and低氧适应性。公共卫生相关性：所有实体瘤都需要在整个肿瘤发生过程中进行微环境适应。这种自适应反应的标志之一是肿瘤内缺氧的发展，刺激了促血管生成/转移基因产物的HIF指导表达。我们的发现表明，在胰腺癌患者子集的血浆中，这些基因产物之一MIF升高。我们进一步描述了细胞外细胞因子/生长因子MIF与转录因子，胰腺导管腺癌（PDAC）细胞中的独特功能相互关系。我们的数据证明了这一点，表明缺乏MIF的细胞表现出缺陷的缺氧和PHD抑制剂诱导的HIF-1A稳定性以及随后的代谢和血管生成基因产物的转录。更重要的是，与含有MIF的细胞相比，PDAC肿瘤发生的异种移植小鼠模型表明，MIF缺陷型肿瘤生长，HIF-1A表达和与肿瘤相关的血管生成相比受到严重损害。据报道，HIF表达直接导致肿瘤侵袭性，胰腺的癌症非常低氧，因此MIF可能在功能上有助于维持肿瘤，环境适应以及最终对胰腺腺癌患者的预后。