Targeting stabilized mutant p53 protein

靶向稳定突变 p53 蛋白

基本信息

批准号：
8640903
负责人：
UTE Martha MOLL
金额：
$ 34.55万
依托单位：
STATE UNIVERSITY NEW YORK STONY BROOK
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-04-01 至 2018-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8640903
关键词：
Ablation Acute Alleles Apoptosis Attention Biological Markers Cancer Patient Carcinoma Cell Survival Cells Chemicals Clinical Clinical Trials Complex DNA Binding Domain Dependency Drug Targeting Drug effect disorder Etiology Excision Exhibits Genetic Goals HDAC6 gene HSPB1 gene Heat-Shock Proteins 90 Human Knockout Mice Lead Life Link Lymphoma Maintenance Malignant - descriptor Malignant Neoplasms Malignant neoplasm of lung Mediating Missense Mutation Modeling Molecular Chaperones Mus Mutation Neoplasm Metastasis Normal tissue morphology Oncogenes Oncogenic Patients Pharmaceutical Preparations Phenotype Pre-Clinical Model Protein p53 Proteins Resistance SCID Mice Sampling Series Skin Carcinogenesis Squamous cell carcinoma Staging System Testing Therapeutic Transplantation Tumor Suppressor Proteins Vorinostat Withdrawal Xenograft procedure base cancer cell chaperone machinery cytotoxicity gain of function in vivo inhibitor/antagonist killings malignant breast neoplasm mouse model mutant next generation novel novel strategies prevent prospective public health relevance research study response sarcoma small molecule tumor tumorigenesis ubiquitin-protein ligase

Ablation Acute Alleles Apoptosis Attention Biological Markers Cancer Patient Carcinoma Cell Survival Cells Chemicals Clinical Clinical Trials Complex DNA Binding Domain Dependency Drug Targeting Drug effect disorder Etiology Excision Exhibits Genetic Goals HDAC6 gene HSPB1 gene Heat-Shock Proteins 90 Human Knockout Mice Lead Life Link Lymphoma Maintenance Malignant - descriptor Malignant Neoplasms Malignant neoplasm of lung Mediating Missense Mutation Modeling Molecular Chaperones Mus Mutation Neoplasm Metastasis Normal tissue morphology Oncogenes Oncogenic Patients Pharmaceutical Preparations Phenotype Pre-Clinical Model Protein p53 Proteins Resistance SCID Mice Sampling Series Skin Carcinogenesis Squamous cell carcinoma Staging System Testing Therapeutic Transplantation Tumor Suppressor Proteins Vorinostat Withdrawal Xenograft procedure base cancer cell chaperone machinery cytotoxicity gain of function in vivo inhibitor/antagonist killings malignant breast neoplasm mouse model mutant next generation novel novel strategies prevent prospective public health relevance research study response sarcoma small molecule tumor tumorigenesis ubiquitin-protein ligase

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项目摘要

DESCRIPTION (provided by applicant): The vast majority of p53 mutations are missense mutations in the DNA-binding domain (mutp53) that generate conformationally aberrant proteins with broadly abrogated functions. Importantly, missense mutp53 proteins not only lose their tumor suppressor function, but often acquire oncogenic gain-of-function (GOF) to drive tumorigenesis. GOF contributes to malignant progression with higher proliferation, invasion, metastatic ability and chemoresistance. A central feature of GOF is that nearly all mutp53 proteins exhibit massive constitutive stabilization, and that stabilization is the prerequisite for exerting GOF. Currently, ~ 11 million people are living with tumors expressing highly stabilized mutp53. Importantly, our findings indicate that the oncogenic 'wiring' of mutp53 tumors fundamentally differs from p53-null tumors, historically the premier preclinical model used. We find that mutp53 cancers have developed a strong dependency on high levels of mutp53 for survival. Thus, its acute withdrawal triggers strong spontaneous cytotoxicity in xenografts. We identified that the heat shock protein 90 chaperone (HSP90) is a major determinant of mutp53 stabilization. This identifies acute depletion of mutp53 as a very promising clinical strategy, and a potentially rather rapidly attainable goal in p53-based therapy. HSP90 is highly upregulated specifically in cancers but not in normal tissues. Importantly, the HSP90 machinery is a crucial facilitator of cancer cell survival by supporting proper folding of conformationally aberrant oncogenes including mutp53. Mechanistically, HSP90 protects mutp53 via stable complex ('caging') from its E3 ligases. Thus, goals of this project are to determine whether established tumors require continued expression of stabilized mutp53 for their maintenance in vivo, and to explore whether destabilizing mutp53 - by attacking the chaperone support on which they depend - is a promising new mutp53-specific anticancer strategy. This is an immensely important unsolved problem that is understudied and urgently needs more attention, with a high translational potential to achieve true clinical impact. Aim 1 determines if continued expression of high levels of mutant p53 is essential for maintenance of established tumors in vivo. We will perform genetic proof-of-principle experiments using acute ablation in mice. To this end, we generated a novel humanized inactivatable mutp53 KI model and will test it in a spontaneous and induced cancer context in vivo. Aim 2 asks whether small molecule inhibitors of the HSP90-HDAC6 chaperone have a preferential therapeutic response in mutp53 cancer cells in vivo. This will be extensively tested in xenografts and two different hotspot mutp53 KI mouse models. We will also test if mutp53 is a predictive biomarker for response to HSP90i-based therapy in three retrospective/ prospective clinical trials of lung and breast cancer patients. Also, causality studies on mechanism of drug action will be performed. Aim 3 is based on a novel unsuspected link between aberrant mutp53 stabilization and the tumor-associated HSP27 chaperone system that we uncovered. We will test if the HSP27 chaperone is a mechanistically independent second determinant of mutp53 stabilization.

描述（由申请人提供）：绝大多数p53突变是DNA结合结构域（MUTP53）中的错义突变，它们产生具有广泛废除功能的构象异常蛋白质。重要的是，错义MUTP53蛋白不仅失去了其肿瘤抑制功能，而且经常获得致癌性获得（GOF）以驱动肿瘤发生。 GOF有助于恶性进展，具有较高的增殖，侵袭，转移能力和化学抗性。 GOF的一个主要特征是，几乎所有的Mutp53蛋白都表现出巨大的本构稳定，并且稳定是前提的先决条件。发挥GOF。目前，约有1100万人患有表达高度稳定的MUTP53的肿瘤。重要的是，我们的发现表明，MUTP53肿瘤的致癌“接线”与p53-null肿瘤的根本不同，这是历史上使用的主要临床前模型。我们发现，Mutp53癌症对高水平的MUTP53产生了强烈的依赖性。因此，其急性戒断会触发异种移植物中强的自发性细胞毒性。我们确定热休克蛋白90伴侣（HSP90）是MUTP53稳定的主要决定因素。这将MUTP53的急性耗竭是一种非常有前途的临床策略，并且在基于p53的治疗中，这是一个可能迅速实现的目标。 HSP90在癌症中特别上调，但在正常组织中没有。重要的是，HSP90机械是癌细胞存活的至关重要的促进因素，它通过支持构象异常的癌基因（包括MUTP53）的适当折叠。从机械上讲，HSP90通过稳定的复合物（caging'）保护Mutp53免受其E3连接酶的影响。因此，该项目的目标是确定已建立的肿瘤是否需要稳定的MUTP53进行体内维持，并探索是否通过攻击伴侣支撑的依赖的伴侣支撑 - 是一种有希望的新MUTP53特异性抗癌策略。这是一个非常重要的未解决的问题，该问题经过研究，迫切需要更多的关注，具有很高的翻译潜力来实现真正的临床影响。 AIM 1决定是否持续表达高水平的突变体p53对于维持体内已建立的肿瘤至关重要。我们将在小鼠中使用急性消融进行遗传原则实验。为此，我们生成了一种新型的人源化不可分割的MUTP53 Ki模型，并将在体内自发和诱导的癌症环境中进行测试。 AIM 2询问HSP90-HDAC6伴侣蛋白的小分子抑制剂是否在体内MUTP53癌细胞中具有优先的治疗反应。这将在异种移植物和两个不同的热点杂种ki小鼠模型中进行广泛测试。我们还将测试MUTP53是否是肺和乳腺癌患者的三项回顾性/前瞻性临床试验中对基于HSP90I的治疗反应的预测生物标志物。此外，还将对药物作用机理进行因果关系研究。 AIM 3基于我们发现的异常MUTP53稳定和与肿瘤相关的HSP27伴侣系统之间的新型无引起的联系。我们将测试HSP27伴侣是否是MUTP53稳定的机械独立的第二决定因素。