Pharmacological targeting of the Unfolded Protein Response as an antitumor strate

未折叠蛋白反应的药理学靶向作为抗肿瘤策略

• 批准号: 7644769
• 负责人: ALBERT KOONG
• 金额: $ 34.55万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-17 至 2011-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7644769
• 关键词: 5' Untranslated Regions; Animals; Anoxia; Attenuated; Biological Assay; Biological Models; Bortezomib; Cell Culture Techniques; Cell Survival; Cells; Cellular Assay; Cellular Stress; Clinical; Collaborations; Cytotoxic agent; Data; Defect; Development; Effectiveness; Embryo; Endoplasmic Reticulum; Environment; Exhibits; Genes; Glucose; Goals; Growth; Growth Factor; Health; Human; Hypoxia; In Vitro; Institution; Kinetics; Label; Luciferases; Malignant Neoplasms; Measures; Metabolic stress; Modality; Modeling; Molecular; Molecular Chaperones; Multiple Myeloma; Mus; Mutate; Oncogenic; Oxygen; Pathway interactions; Phenotype; Phosphotransferases; Physiological; Physiology; Play; Preclinical Drug Evaluation; Process; Property; Proteasome Inhibitor; Proteins; Publishing; Reporter; Resistance; Role; Screening procedure; Solid Neoplasm; Stress; System; Testing; Therapeutic; Time; Toxic effect; Transgenic Mice; Transgenic Organisms; Translations; Transplantation; Treatment Efficacy; Tumor Burden; Up-Regulation; Upper arm; Work; Xenograft procedure; Zebrafish; angiogenesis; antitumor agent; base; cell transformation; chemotherapeutic agent; cytotoxic; design; efficacy testing; endonuclease; endoplasmic reticulum stress; improved; in vivo; inhibitor/antagonist; killings; neoplastic cell; novel; novel strategies; pre-clinical; programs; public health relevance; research study; response; small molecule; small molecule libraries; tumor; tumor growth; tumor progression; tumor xenograft; tumorigenesis

DESCRIPTION (provided by applicant): Hypoxia/anoxia is a well-characterized component of the microenvironment of most solid tumor. Considerable experimental and clinical evidence supports the notion that hypoxia fundamentally alters the physiology of the tumor towards a more aggressive phenotype. The Unfolded Protein Response (UPR) is a cellular stress adaptation pathway which promotes cell survival in the presence of Endoplasmic Reticulum (ER) stress, including physiological stress in the tumor microenvironment. The PERK/eIF2a/ATF4 pathway reduces the global rates of protein translation thereby alleviating metabolic stress under hypoxia while at the same time induces the translational upregulation of important chaperones and pro-survival genes. Another UPR component is the activation of the endonuclease/kinase IRE1 and its immediate effector XBP1, which activate a transcriptional program aimed at increasing the folding capacity of the ER. Recent in vitro and in vivo studies from the labs of the two co-PIs, have shown that transformed cells with ablated UPR responses exhibit reduced tolerance to hypoxia in vitro and form tumors that are slower growing compared to tumors grown from cells with an intact UPR, indicating that UPR activation contributes to tumorigenesis. In preliminary studies, we have developed cell-based and animal-based assays for UPR activation and its inhibition by small molecules. The overall goal of this proposal is to validate UPR activation as an important anti- tumor target and to use novel in vitro and in vivo assays to identify potent inhibitors of this response as novel chemotherapeutic agents. In Aim 1, we will employ in vitro reporter assays of PERK activity to identify specific inhibitors of the PERK/eIF21/ATF4 pathway and test the effect of combined administration of these inhibitors with inhibitors of the IRE-1 pathway (Irestatins) on tumor cell survival under normoxia and hypoxia. In Aim 2, we will investigate the potential synergy between inhibitors of the PERK and IRE1 pathways with the proteasome inhibitor Bortezomib in killing hypoxic tumor cells in vitro and in vivo. Studies under Aim 3, will evaluate the use of Zebrafish as a model system to analyze the ability of inhibitors of the PERK and IRE1 pathways to inhibit xenotransplanted human tumors and to inhibit angiogenesis without causing significant developmental abnormalities. Finally, in Aim 4 we will test the efficacy and potential toxicity of identified compounds in mouse tumor models. We expect that these efforts will culminate in the development of specific and potent inhibitors of the UPR which alone, or in combination with existing antitumor agents and modalities will be effective in reducing tumor burden in preclinical and clinical malignancies. PUBLIC HEALTH RELEVANCE: A hallmark of solid tumors is the requirement to adapt to, and eventually overcome the stressful environment of low oxygen, growth factors, glucose and pH in the growing tumor mass. The requirement for neoangiogenesis to support tumor growth is now well established and is the basis for several promising anti-tumor modalities. Based on published data from our labs and others, we propose that the Unfolded Protein Response also plays a crucial role in adaptation to hypoxic stress, and like angiogenesis, represents an "encompassing and stable aspect of tumor development" and thus provides a unique opportunity for therapeutic exploitation. This proposal aims to identify agents that target key components of this adaptive response has the potential to offer additional and novel approaches to target the very stresses that hinder existing anti-tumor treatments and thereby improve antitumor treatment efficacy.

描述(申请人提供)：缺氧/缺氧是大多数实体肿瘤微环境的一个很好的特征成分。大量的实验和临床证据支持低氧从根本上改变肿瘤的生理学，使其向更具侵袭性的表型转变。未折叠蛋白反应(UPR)是一种细胞应激适应途径，在内质网(ER)应激(包括肿瘤微环境中的生理性应激)的存在下促进细胞存活。PERK/eIF2a/ATF4途径降低了蛋白质翻译的全局速率，从而缓解了低氧下的代谢应激，同时诱导了重要的伴侣和促生存基因的翻译上调。UPR的另一个组成部分是内切酶/激酶IRE1及其直接效应因子XBP1的激活，它激活了一个旨在增加内质网折叠能力的转录程序。最近来自两个联合PI实验室的体外和体内研究表明，具有消融UPR反应的转化细胞在体外对缺氧的耐受性降低，并且形成的肿瘤比从完整的UPR细胞生长的肿瘤生长得更慢，这表明UPR激活有助于肿瘤的发生。在初步研究中，我们开发了基于细胞和动物的UPR激活及其被小分子抑制的方法。这项建议的总体目标是验证UPR激活作为一个重要的抗肿瘤靶点，并使用新的体外和体内试验来确定这种反应的有效抑制剂作为新的化疗药物。在目标1中，我们将使用体外PERK活性的报告分析来确定PERK/eIF21/ATF4途径的特异性抑制剂，并测试这些抑制剂与IRE-1途径的抑制剂(Irestatins)联合应用对常氧和低氧条件下肿瘤细胞存活的影响。在目标2中，我们将研究PERK和IRE1通路的抑制剂与蛋白酶体抑制剂Bortezomib在体外和体内杀灭缺氧肿瘤细胞的潜在协同作用。AIM 3下的研究将评估斑马鱼作为模型系统的使用，以分析PERK和IRE1途径的抑制剂抑制异种移植的人类肿瘤和抑制血管生成的能力，而不会导致显著的发育异常。最后，在目标4中，我们将在小鼠肿瘤模型中测试已识别的化合物的有效性和潜在毒性。我们期望这些努力将最终导致UPR特异性和强效抑制剂的开发，这些药物单独或与现有的抗肿瘤药物和方法联合使用将在减轻临床前和临床恶性肿瘤的肿瘤负担方面有效。与公共健康相关：实体肿瘤的一个特点是需要适应并最终克服不断生长的肿瘤块中低氧、生长因子、葡萄糖和pH的应激环境。新血管生成支持肿瘤生长的要求现在已经确立，并且是几种有前景的抗肿瘤方法的基础。根据我们实验室和其他机构公布的数据，我们认为，展开的蛋白反应在适应低氧应激中也发挥着关键作用，与血管生成一样，代表着“肿瘤发展的一个全面和稳定的方面”，因此为治疗开发提供了独特的机会。这项建议旨在找出针对这种适应性反应的关键成分的药物，有可能提供额外的和新的方法来针对阻碍现有抗肿瘤治疗的应激反应，从而提高抗肿瘤治疗的效果。