Function and Regulation of the BCL-2 Family

BCL-2 家族的功能和调节

• 批准号: 10576308
• 负责人: Jerry Edward Chipuk
• 金额: $ 37.89万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-01 至 2025-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10576308
• 关键词: Affinity; Apoptosis; Apoptotic; BCL-2 Protein; BCL2L11 gene; Binding; Biochemical; Biological Models; Biophysics; Cancer Biology; Cancer Etiology; Cancer Model; Carbon; Caspase; Cell Membrane Permeability; Cells; Chemoresistance; Chemotherapy and/or radiation; Classification; Clinical; Collaborations; Coupled; Cytoplasm; Data; Environment; Excision; Family; Fibroblasts; Foundations; Human; Knowledge; Laboratories; Lead; Lipids; Maintenance; Malignant Neoplasms; Mediating; Mitochondria; Modeling; Molecular; Molecular Conformation; Mus; Outer Mitochondrial Membrane; Pathway interactions; Phase; Phenotype; Process; Proteins; Proteolipids; Radiation therapy; Regulation; Research; Resistance; Role; Sphingolipids; Stress; Structure; System; Techniques; Therapeutic; Validation; Xenograft procedure; analog; biophysical techniques; cancer cell; cancer therapy; cell injury; cell suicide; cheminformatics; experimental study; insight; malignant state; melanoma; mitochondrial membrane; mutant; novel; novel therapeutic intervention; prevent; programs; protein B; protein activation; protein function; protein protein interaction; screening; sensor; small molecule; success; treatment response; tumor initiation; tumorigenesis; virtual screening

PROJECT SUMMARY The impact of the mitochondrial pathway of apoptosis on cancer biology is broad because the BCL-2 (B-cell CLL/Lymphoma 2) family regulates tumor initiation and maintenance, and is directly targeted by anti- cancer therapies. Therefore, a mechanistic understanding of BCL-2 family function will advance our knowledge of the pathways that cause cancer, and are clinically targeted to cure cancer. The mitochondrial pathway of apoptosis proceeds when the BCL-2 family collaborates to compromise the outer mitochondrial membrane (OMM). This process, referred to as mitochondrial outer membrane permeabilization (MOMP), allows for pro- apoptotic factors within mitochondria to gain access to the cytoplasm, which leads to caspase activation and rapid dismantling and removal of the targeted cell. BAX (BCL-2 associated X protein) is the major pro-apoptotic BCL-2 protein that engages MOMP by creating proteolipid pores in the OMM. BAX-dependent MOMP inhibits tumorigenesis, and on the flipside, BAX-dependent apoptosis is induced by a majority of conventional and targeted chemotherapeutics. In order for BAX to gain pro-apoptotic function, it has two general requirements: (1) BAX needs to interact with a subset of the pro-apoptotic BCL-2 family: the “direct activator” BH3-only proteins, e.g., BID and BIM; and (2) BAX requires stable interactions with mitochondrial lipids to structurally rearrange leading to BAX’s insertion, oligomerization, and pore formation. While decades of research have focused on understanding the first requirement, little has been discovered on how mitochondrial environment mechanistically contributes to MOMP. Over the years, my laboratory showed that mitochondrial environment directly controls BAX function, and the mitochondrial-produced 16-carbon sphingolipid metabolite 2-trans- hexadecenal (2-t-hex) is required for BAX activation and BAX-dependent apoptosis. By utilizing novel mitochondrial model systems coupled with state-of-the-art biochemical, cellular, and structural techniques, we are now ready to determine the mechanistic contributions of 2-t-hex within the BAX activation process, and more broadly, to reveal how 2-t-hex binding defines functional classifications within the BCL-2 family. Furthermore, we generated evidence that cancer cells specifically disrupt the cooperation between BAX and 2- t-hex leading to apoptotic resistance – and identified ‘first-in-class’ small molecules to overcome this phenotype. Our broad objectives are to build a foundation of novel mechanistic insights into the role of 2-t-hex on BAX-dependent apoptosis and the BCL-2 family, and to use this information to develop novel therapeutic strategies against cancer. These objectives will be accomplished in three complementary aims: (1) Define the molecular mechanism of 2-t-hex mediated BAX activation; (2) Elucidate the molecular mechanism by which S- nitrosylation of BAX promotes apoptotic resistance in cancer; and (3) Identify, refine, and characterize “first-in- class” therapeutics that transform S-nitrosylated BAXCys62 from apoptosis-resistant to apoptosis-competent thus promoting chemotherapeutic success.

项目摘要 凋亡对癌症生物学的线粒体途径的影响很广，因为Bcl-2 （B细胞CLL/淋巴瘤2）家族调节肿瘤倡议和维持，并直接由抗 - 癌症疗法。因此，对BCL-2家庭功能的机械理解将提高我们的知识 引起癌症的途径，并在临床上旨在治愈癌症。线粒体途径 当Bcl-2家族合作以妥协外部线粒体膜时，凋亡进行 （OMM）。这个过程，称为线粒体外膜透化（MOMP），允许促进 线粒体内的凋亡因子可以进入细胞质，从而导致caspase激活和 快速拆除和去除目标细胞。 Bax（Bcl-2相关X蛋白）是主要的促凋亡 通过在OMM中产生蛋白质毛孔来吸引MOMP的Bcl-2蛋白。 BAX依赖性MOMP抑制 肿瘤发生，在另一方面，大多数常规和 有针对性的化学治疗药。为了使Bax获得促凋亡功能，它具有两个一般要求： （1）Bax需要与促凋亡Bcl-2家族的一部分相互作用：“直接激活剂”仅BH3-bh3 蛋白质，例如出价和BIM； （2）Bax需要与线粒体脂质稳定相互作用到结构上 重新排列导致Bax的插入，低聚和孔形成。而数十年的研究已经 专注于理解第一个要求，关于线粒体环境的发现很少 机械地有助于MOMP。多年来，我的实验室表明线粒体环境 直接控制BAX功能，线粒体生产的16-碳鞘脂代谢产物2型trans- Bax激活和BAX依赖性凋亡是必需的六二核（2-T-HEX）。通过使用小说 线粒体模型系统以及最先进的生化，细胞和结构技术，我们 现在准备确定BAX激活过程中2-T-HEX的机械贡献，并且 从更广泛的角度来看，要揭示2-T-HEX结合如何定义Bcl-2家族中的功能分类。 此外，我们产生了证据，表明癌细胞特别破坏了Bax和2-之间的合作。 T-HEX导致凋亡抗性 - 并确定了“第一类”的小分子来克服这一点 表型。我们广泛的目标是建立对2-T-HEX作用的新型机械见解的基础 关于Bax依赖性凋亡和BCL-2家族，并使用此信息开发新的疗法 反对癌症的策略。这些目标将以三个完整的目的来实现：（1）定义 2-T-HEX介导的BAX激活的分子机制； （2）阐明S-的分子机制 BAX的硝基化促进癌症的凋亡抗性； （3）识别，完善和表征“首先 类别的疗法将S-亚硝基化的Baxcys62从抗凋亡抗凋亡竞争的疗法转化 促进化学治疗成功。