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: 8294818
• 负责人: ALBERT KOONG
• 金额: $ 32.09万
• 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 2013-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8294818
• 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; Work; Xenograft procedure; Zebrafish; angiogenesis; antitumor agent; arm; 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; 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（由申请人提供）：缺氧/缺氧是大多数实体瘤微环境的一个特征良好的组成部分。大量的实验和临床证据支持缺氧从根本上改变肿瘤的生理学，使其具有更具侵袭性的表型。未折叠蛋白反应（UPR）是一种细胞应激适应途径，其在内质网（ER）应激（包括肿瘤微环境中的生理应激）存在下促进细胞存活。PERK/eIF 2a/ATF 4途径降低蛋白质翻译的总体速率，从而减轻缺氧下的代谢应激，同时诱导重要分子伴侣和促存活基因的翻译上调。另一个UPR组分是核酸内切酶/激酶IRE 1及其直接效应因子XBP 1的激活，其激活旨在增加ER折叠能力的转录程序。最近来自两个co-PI实验室的体外和体内研究表明，具有消融的UPR反应的转化细胞在体外表现出对缺氧的耐受性降低，并且与从具有完整UPR的细胞生长的肿瘤相比，形成生长较慢的肿瘤，表明UPR活化有助于肿瘤发生。在初步研究中，我们已经开发了基于细胞和基于动物的UPR激活及其抑制小分子的测定。该提案的总体目标是验证UPR活化作为重要的抗肿瘤靶点，并使用新的体外和体内测定来鉴定该反应的有效抑制剂作为新的化疗剂。在目的1中，我们将采用PERK活性的体外报告基因测定来鉴定PERK/eIF 21/ATF 4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（伊瑞他汀）联合施用对常氧和缺氧下肿瘤细胞存活的影响。在目标2中，我们将研究PERK和IRE 1通路的抑制剂与蛋白酶体抑制剂Bortezaline在体外和体内杀死缺氧肿瘤细胞中的潜在协同作用。目标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IRE 1通路抑制剂抑制异种移植的人类肿瘤和抑制血管生成而不引起显著发育异常的能力。最后，在目标4中，我们将在小鼠肿瘤模型中测试所鉴定的化合物的功效和潜在毒性。我们预计这些努力将最终导致开发特异性和有效的UPR抑制剂，其单独或与现有的抗肿瘤药物和方式组合将有效降低临床前和临床恶性肿瘤的肿瘤负荷。公共卫生关系：实体瘤的标志是需要适应并最终克服生长肿瘤块中的低氧、生长因子、葡萄糖和pH的应激环境。支持肿瘤生长的新血管生成的要求现在已经得到很好的确立，并且是几种有前途的抗肿瘤模式的基础。基于我们实验室和其他人发表的数据，我们提出，未折叠蛋白反应在适应缺氧应激中也起着至关重要的作用，并且与血管生成一样，代表了“肿瘤发展的包容性和稳定性”，因此为治疗开发提供了独特的机会。该提案旨在确定靶向这种适应性反应的关键成分的药物，这些药物有可能提供额外的和新的方法来靶向阻碍现有抗肿瘤治疗的压力，从而提高抗肿瘤治疗效果。