Dissecting and Targeting Deregulated Mitochondrial Apoptosis in Human Cancer

剖析和靶向人类癌症中失调的线粒体凋亡

• 批准号: 8955883
• 负责人: Loren David Walensky
• 金额: $ 104.34万
• 依托单位: DANA-FARBER CANCER INST
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-10 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8955883
• 关键词: Address; Apoptosis; Apoptotic; BAX gene; BCL-2 Protein; BCL2 gene; BH4 Domain; Biochemistry; Biological; Biology; Cancer Research Project; Cell Death; Cells; Cellular biology; Cessation of life; Chemicals; Chemistry; Complex; Deuterium; Development; Equilibrium; Family; Family Research; Goals; Homeostasis; Homo; Human; Hydrogen; Laboratories; Laboratory Research; Life; Maintenance; Malignant - descriptor; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Membrane; Methods; Mitochondria; Pediatric Oncologist; Pharmaceutical Preparations; Pharmacology; Protein Family; Proteins; Proteomics; Resistance; Signal Transduction; Site; Stress; Structure; Surface; Time; cancer cell; cancer therapy; inhibitor/antagonist; insight; interdisciplinary approach; mouse model; next generation; novel; novel strategies; novel therapeutics; peptide structure; public health relevance; response; small molecule; structural biology; tool

 DESCRIPTION (provided by applicant): The BCL-2 family of apoptotic proteins regulates the critical balance between cellular life and death. Deregulation of this essential signal transductio network drives the development, maintenance, and chemoresistance of a broad spectrum of human cancers. My laboratory is addressing the questions of just how interactions among BCL-2 family proteins regulate their structural changes and signaling functions during homeostasis and malignant transformation. Because BCL-2 protein interactions determine whether the cell will live or die in response to stress, we believe these structure-function studies will both infor basic biological mechanisms and opportunities to pharmacologically modulate them. Thirty years of BCL-2 family research has led to the first small molecule drug to reactive apoptosis in BCL-2 dependent cancer. Despite this remarkable scientific progress and the renewed promise of targeting BCL-2 proteins in cancer, fundamental questions remain about how this complex protein family regulates mitochondrial apoptosis. Indeed, their predominant membrane localization has made BCL-2 family proteins remarkably challenging to study. How the activated forms of BAX and BAK self-assemble into toxic oligomeric pores - the very death channels that mediate apoptosis - is unknown. How anti-apoptotic proteins such as BCL-2 change their structure within the membrane to block the various steps of BAX/BAK activation is unknown. Indeed, the full spectrum of contact surfaces between the many conserved domains of BCL-2 proteins is unknown. Perhaps the most perplexing question of how such structurally similar proteins can have diametrically opposite functions, as either inhibitors or activators of cell deat, remains essentially unknown. We address these mechanistic questions with broad experimental approaches, spanning chemistry, structural biology, proteomics, biochemistry, cell biology, mouse modeling, and pharmacology. For example, we have developed new chemical tools to dissect and target BCL-2 family protein interactions, advanced new methods to rapidly and accurately identify interaction sites using photoreactive structured peptides and mass spectrometry, and are currently applying hydrogen- deuterium exchange mass spectrometry to study BCL-2 family conformational changes in the membrane in real-time for the first time. Our goals for this R35 cancer research program include defining the conformational activation and homo-oligomerization mechanism(s) of BAX and BAK, characterizing a novel mechanism for BAX and BAK suppression by the BH4 domains of anti-apoptotic BCL-2 proteins, and investigating a new allosteric mechanism that controls the apoptotic functionalities of BCL-2 proteins. In each case, the structure- function insights will be harnessed to develop new approaches for targeting apoptotic resistance in cancer. As a chemical biologist and practicing pediatric oncologist, I have dedicated my research laboratory to deciphering BCL-2 family-mediated cancer mechanisms so that fresh insights into their protein interaction biology can inform the next generation of pro-apoptotic therapies for human cancer.

 描述（由申请人提供）：凋亡蛋白的 BCL-2 家族调节细胞生与死之间的关键平衡。这种重要信号转导网络的失调会驱动多种人类癌症的发展、维持和化疗耐药性。我的实验室正在解决 BCL-2 家族蛋白之间的相互作用如何在稳态和恶性转化过程中调节其结构变化和信号传导功能的问题。由于 BCL-2 蛋白相互作用决定细胞在应激反应中生存还是死亡，我们相信这些结构功能研究将提供基本的生物学机制和药理学调节它们的机会。经过三十年的 BCL-2 家族研究，我们开发出了第一种能够在 BCL-2 依赖性癌症中发生反应性细胞凋亡的小分子药物。尽管取得了显着的科学进展，并且针对癌症中的 BCL-2 蛋白有了新的希望，但关于这一复杂蛋白家族如何调节线粒体凋亡的基本问题仍然存在。事实上，BCL-2 家族蛋白的主要膜定位使得研究变得非常具有挑战性。 BAX 和 BAK 的激活形式如何自组装成有毒寡聚孔（介导细胞凋亡的死亡通道）尚不清楚。 BCL-2 等抗凋亡蛋白如何改变其膜内结构以阻断 BAX/BAK 激活的各个步骤尚不清楚。事实上，BCL-2 蛋白的许多保守结构域之间的接触面的全谱尚不清楚。也许最令人困惑的问题是，这种结构相似的蛋白质如何能够具有截然相反的功能，作为细胞死亡的抑制剂或激活剂，仍然基本上未知。我们通过广泛的实验方法解决这些机制问题，涵盖化学、结构生物学、蛋白质组学、生物化学、细胞生物学、小鼠建模和药理学。例如，我们开发了新的化学工具来剖析和靶向BCL-2家族蛋白的相互作用，先进的新方法利用光反应结构肽和质谱法快速准确地识别相互作用位点，并且目前正在首次应用氢-氘交换质谱法实时研究膜中的BCL-2家族构象变化。我们这个 R35 癌症研究计划的目标包括定义 BAX 和 BAK 的构象激活和同源寡聚机制，表征抗凋亡 BCL-2 蛋白的 BH4 结构域抑制 BAX 和 BAK 的新机制，以及研究控制 BCL-2 蛋白凋亡功能的新变构机制。在每种情况下，结构-功能见解将被用来开发针对癌症细胞凋亡抵抗的新方法。作为一名化学生物学家和执业儿科肿瘤学家，我的研究实验室致力于破译 BCL-2 家族介导的癌症机制，以便对其蛋白质相互作用生物学的新见解可以为下一代人类癌症促凋亡疗法提供信息。