Dissecting and targetting HDMX-medicated chemoresistance in human cancer

剖析和靶向人类癌症中 HDMX 药物的化疗耐药性

基本信息

批准号：
9396622
负责人：
Ann Morgan Cathcart
金额：
$ 3.57万
依托单位：
DANA-FARBER CANCER INST
依托单位国家：
美国
项目类别：
财政年份：
2017
资助国家：
美国
起止时间：
2017-08-01 至 2019-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9396622
关键词：
Acute Myelocytic Leukemia Alanine Apoptosis Apoptotic Binding Biological Assay Biotin CRISPR/Cas technology Cancer Biology Cancer cell line Cell Cycle Arrest Cell Death Cell Line Cells Chemicals Chemistry Clinical Oncology Complement Complex Crystallization DNA Damage Dana-Farber Cancer Institute Dependency Deuterium Elements Employee Strikes Epitopes Exhibits Fluorescence Polarization Genes Genetic Glutamic Acid Goals Hdmx protein Homeostasis Human Hydrogen Impairment Individual Investigational Therapies Knock-out Lead Libraries Ligands Lysine MDM2 gene Malignant Neoplasms Mass Spectrum Analysis Measures Mediating Modeling Molecular Conformation Mus Mutate Oncogenic Pathologic Pathway interactions Peptides Pharmacology Physicians Predisposition Protein p53 Proteins Recombinants Resistance Role Scanning Scientist Signal Transduction Streptavidin Structure TP53 gene Technology Testing Therapeutic Training Programs Transactivation Variant X-Ray Crystallography Xenograft Model alpha helix cancer cell career chemical synthesis chemotherapeutic agent design efficacy testing in vivo inhibitor/antagonist insight interdisciplinary approach medical schools multidisciplinary next generation novel novel therapeutic intervention novel therapeutics overexpression preference protein structure prototype research clinical testing small molecule tool tumor uptake

项目摘要

PROJECT SUMMARY/ABSTRACT The p53 tumor suppressor protein regulates critical control points of cellular homeostasis, including protecting cellular DNA from damage that could predispose to cancer. Indeed, a fully operational p53 signaling network is required for the pro-apoptotic activity of many chemotherapeutic agents. Whereas p53 can be mutated or deleted in cancer to avoid cell cycle arrest or apoptosis, a frequent alternative mode of p53 suppression relies on overexpression of the negative regulators HDMX and HDM2, which neutralize p53 through protein interaction. The individual contributions of HDMX and HDM2 to p53 suppression and chemoresistance in human cancers are largely unknown. Interestingly, we observe a relatively consistent level of HDM2 expression across a large and diverse panel of cancer cells, whereas HDMX manifests more variable expression, with subtypes such as acute myeloid leukemia exhibiting among the highest HDMX levels. What's more, HDMX scored in the top gene dependencies for several AML cell lines that also maintain wild-type p53 expression. These findings suggest that selective targeting of HDMX could both inform the mechanistic role of HDMX dependency in cancer and provide a therapeutic strategy for restoring the p53-pathway in HDMX-driven cancers. Whereas small molecule and stapled peptide inhibitors, which respectively inhibit HDM2 selectively or target both HDM2 and HDMX, have now been advanced to clinical testing, no validated HDMX-specific agent has been developed or validated to date. In addition, the influence of ligand engagement of HDMX and HDM2 on protein structure and the conformational dynamics of their p53 complexes is essentially unknown. Here, I aim to apply chemical, structural, cellular, and in vivo approaches to identify the binding determinants for selective targeting of HDMX, evaluate the structural and functional consequences of selective HDMX engagement, and advance a therapeutic strategy for reactivating p53-mediated apoptosis in HDMX-driven chemoresistant cancers. To achieve these goals, I propose three experimental aims: (1) synthesize libraries of structurally-reinforced alpha-helices modeled after the p53 transactivation domain to characterize their interactions with HDMX and HDM2, and identify selectivity determinants, (2) elucidate the conformational effects of SAH-p53 peptide engagement on HDMX and HDM2 proteins, alone and in complex with p53, and (3) advance lead HDMX-specific peptide inhibitors to cellular and in vivo testing to validate specific inhibition of HDMX as a therapeutic strategy for overcoming chemoresistance in cancers that retain wildtype p53 expression. I am eager to embark on a rigorous and multidisciplinary training program to accomplish the above-proposed graduate studies at Harvard Medical School and the Dana-Farber Cancer Institute, and look forward to an impactful physician-scientist career at the interface of chemistry, cancer biology, experimental therapeutics, and clinical oncology.

项目摘要/摘要 p53肿瘤抑制蛋白调节细胞稳态的关键控制点，包括保护细胞DNA免受可能易受癌症的损害。确实，完全操作的p53信号传导许多化学治疗剂的促凋亡活性需要网络。 p53可以是在癌症中突变或删除以避免细胞周期停滞或凋亡，这是p53的常见替代模式抑制依赖于负调节剂HDMX和HDM2的过表达，它中和p53 通过蛋白质相互作用。 HDMX和HDM2对p53抑制的个人贡献以及人类癌症中的化学抗性在很大程度上是未知的。有趣的是，我们观察到一个相对一致的水平在大量多样的癌细胞中的HDM2表达表达，诸如急性髓样白血病等亚型在最高的HDMX水平中表现出来。是什么更多，HDMX在几种AML细胞系的顶部基因依赖性中得分，这些AML细胞系也维持野生型p53 表达。这些发现表明，选择性靶向HDMX都可以告知 HDMX癌症的依赖性，并提供了用于恢复HDMX驱动的p53-pathway的治疗策略癌症。小分子和钉钉肽抑制剂分别有选择地抑制HDM2或 HDM2和HDMX的靶标，现在已进入临床测试，未经验证的HDMX特异性剂迄今已开发或验证。此外，HDMX和HDM2的配体参与的影响关于蛋白质结构和p53复合物的构象动力学基本上未知。在这里，我旨在采用化学，结构，细胞和体内方法来识别结合决定因素选择性靶向HDMX，评估选择性HDMX的结构和功能后果参与，并推进针对HDMX驱动的p53介导的凋亡重新激活的治疗策略化学抗药性癌症。为了实现这些目标，我提出了三个实验目标：（1）合成的库以p53反式激活结构域进行建模的结构增强α-螺旋体，以表征其与HDMX和HDM2的相互作用，并识别选择性决定因素，（2）阐明构象 SAH-p53肽参与对HDMX和HDM2蛋白的影响，单独使用p53和（3）提前铅HDMX特异性肽抑制剂对细胞和体内测试，以验证特定的抑制 HDMX作为保留WildType p53的癌症中化学耐药性的治疗策略表达。我渴望着手进行严格而多学科的培训计划，以完成哈佛医学院和达纳 - 法伯癌研究所的高层研究生研究在化学，癌症生物学，实验性的界面上，前往有影响力的医师科学家职业治疗剂和临床肿瘤学。