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

• 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
• 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

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.

项目总结/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免受可能导致癌症的损伤。事实上，一个完全运作的p53信号 网络是许多化疗剂的促凋亡活性所必需的。p53可以是 在癌症中突变或缺失，以避免细胞周期停滞或凋亡，这是p53的一种常见的替代模式 抑制依赖于中和p53的负调节因子HDMX和HDM 2的过度表达 通过蛋白质的相互作用。HDMX和HDM 2对p53抑制的单独贡献， 人类癌症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， HDM 2在大量不同的癌细胞中表达的差异，而HDMX表现出更多的可变性。 HDMX的表达，其中亚型如急性髓性白血病表现出最高的HDMX水平。是什么 此外，HDMX在几种AML细胞系中的基因依赖性得分最高，这些细胞系也保持野生型p53 表情这些发现表明，HDMX的选择性靶向既可以告知HDMX的机制作用， HDMX依赖性，并提供了一种治疗策略，用于恢复HDMX驱动的癌症中的p53通路。 癌的而分别选择性抑制HDM 2或HDM 3的小分子和钉合肽抑制剂， 同时针对HDM 2和HDMX，现已进入临床试验阶段，目前还没有经过验证的HDMX特异性试剂 到目前为止已经开发或验证。此外，HDMX和HDM 2的配体接合的影响 对蛋白质结构及其p53复合物的构象动力学的影响基本上是未知的。这里我 目的是应用化学，结构，细胞和体内方法来确定结合决定簇， 选择性地针对HDMX，评估选择性HDMX的结构和功能后果 参与，并提出重新激活p53介导的HDMX驱动的细胞凋亡的治疗策略。 耐药癌症为了实现这些目标，我提出了三个实验目标：（1）合成 在p53反式激活结构域之后建模的结构增强的α-螺旋，以表征其 与HDMX和HDM 2的相互作用，并确定选择性决定因素，（2）阐明构象 SAH-p53肽接合对单独的和与p53复合的HDMX和HDM 2蛋白的影响，和（3） 推进HDMX特异性肽抑制剂的细胞和体内测试，以验证HDMX特异性抑制 HDMX作为克服保留野生型p53的癌症中的化学抗性的治疗策略 表情我渴望开始一个严格的和多学科的培训计划，以完成 在哈佛医学院和丹娜-法伯癌症研究所进行上述研究生学习， 期待在化学，癌症生物学，实验生物学和生物学的界面上有影响力的医生-科学家职业生涯 治疗学和临床肿瘤学。