RIPK-dependent necrosis in development and cancer

发育和癌症中的 RIPK 依赖性坏死

基本信息

批准号：
8856171
负责人：
DOUGLAS R GREEN
金额：
$ 36.31万
依托单位：
ST. JUDE CHILDREN'S RESEARCH HOSPITAL
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-06 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8856171
关键词：
2q33 APAF1 gene Ablation Achievement Animals Apoptosis Apoptotic Appearance Binding Caspase Cell Death Cells Cessation of life Complex Cysteine Defect Development Elements Embryo Employee Strikes Failure Genetic Genetic Transcription Hematopoietic Histocompatibility Testing Homeostasis Human Inflammatory Knock-out Lead Life Ligands Ligation Liver Malignant Neoplasms Mediating Mitochondria Modeling Mus Necrosis Neuroblastoma Pathway interactions Peptide Hydrolases Phenotype Phosphotransferases Process RIPK1 gene RIPK3 gene Regulation Resistance Role Signal Pathway Signal Transduction TNFRSF6 gene Testing Tissues Tumor Immunity Tumor Suppressor Proteins Vascular Endothelium Vascularization Yolk Sac adapter protein base cancer therapy caspase-3 caspase-8 caspase-9 cell type human disease in vivo lung small cell carcinoma mature animal neoplastic cell prevent progenitor programs protein function receptor tumor tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): While the role of caspases in apoptosis is well established, little is known about the role of these proteases in the process of programmed necrosis. This application is based on startling findings that show that embryonic lethality as a result of ablation of caspase-8 or its adapter protein, FADD, is fully rescued by deletion of RIPK3, a kinase required for programmed necrosis. Our studies indicate that a complex of FADD, caspase-8, and FLIP, a caspase-like molecule that lacks a catalytic cysteine, protects against RIPK-dependent necrosis. This is further supported by our finding that the FADD-FLIP-RIPK3 TKO mouse develops normally. We propose the following studies to delineate the functions of these proteins in development and cancer: Aim 1. What is the developmental target protected by the FADD-caspase-8-FLIPL complex? The phenotypes of the caspase- 8, FADD, and FLIPL knockouts all show embryonic lethality around e10.5, associated with a defect in yolk sac vascularization. In this aim, we will test the idea that early progenitors of vascular endothelium and hematopoietic cells serve as the earliest and most important targets of this developmental defect. In so doing, we will identify additional targets of RIPK3-necrosis and investigate the signaling pathways engaged in this embryonic lethality. Aim 2. How is RIPK-dependent necrosis regulated in oncogenesis? Caspase-8, which in humans is present on 2q33, is often silenced or deleted in human neuroblastoma, small cell lung carcinoma, and other cancers. This represents a paradox, however, as such loss in many cell types sensitizes cells to RIPK-dependent necrosis. Here we explore how loss of caspase-8 can fail to sensitize tumor lines to RIPK-dependent necrosis. Our studies include how RIPK3 transcription is controlled in primary and transformed tissues and the role of RIPK1 and the tumor suppressor, CYLD, in controlling RIPK-dependent necrosis. Aim 3. Does RIPK-dependent necrosis represent a potential avenue for therapy? Many approaches to cancer therapy seek to promote apoptosis, which may or may not promote ancillary anti-tumor immunity. By shifting signals to RIPK-necrosis we may a) prevent iatrogenic damage in tissues resistant to this form of death (e.g., liver) while b) promoting an inflammatory mode of tumor cell death. We will model "pure" RIK3-induced necrosis versus apoptosis to examine the anti-tumor consequences, and will explore a counter- intuitive approach to triggering RIPK-dependent necrosis in autochthonous and grafted tumors by death receptor ligation in vivo. The possibility that tumor neo-vasculature is targeted (based on considerations from Aim 1) will also be explored. These studies provide a number of tests and explorations of the new model we propose, and hold the potential to greatly increase of understanding of this fundamental process controlling life cell and death, both in normal development and in cancer.

描述（由申请人提供）：虽然半胱天冬酶在细胞凋亡中的作用已被充分确定，但人们对这些蛋白酶在程序性坏死过程中的作用知之甚少。该应用基于令人震惊的发现，该发现表明，由于 caspase-8 或其衔接蛋白 FADD 消融而导致的胚胎致死性，可以通过删除 RIPK3（一种程序性坏死所需的激酶）来完全挽救。我们的研究表明，FADD、caspase-8 和 FLIP（一种缺乏催化半胱氨酸的 caspase 样分子）的复合物可防止 RIPK 依赖性坏死。我们的发现进一步支持了这一点，即 FADD-FLIP-RIPK3 TKO 小鼠发育正常。我们建议进行以下研究来描述这些蛋白质在发育和癌症中的功能：目标 1. FADD-caspase-8-FLIPL 复合物保护的发育目标是什么？ caspase-8、FADD 和 FLIPL 敲除的表型均在 e10.5 左右表现出胚胎致死性，与卵黄囊血管化缺陷相关。为此，我们将测试血管内皮和造血细胞的早期祖细胞是这种发育缺陷最早和最重要的目标的观点。在此过程中，我们将确定 RIPK3 坏死的其他靶点，并研究参与这种胚胎致死性的信号通路。目标 2. RIPK 依赖性坏死在肿瘤发生过程中是如何受到调节的？ Caspase-8 在人类中存在于 2q33 上，在人类神经母细胞瘤、小细胞肺癌和其他癌症中通常被沉默或删除。然而，这代表了一个悖论，因为许多细胞类型中的这种损失会使细胞对 RIPK 依赖性坏死敏感。在这里，我们探讨 caspase-8 的缺失如何无法使肿瘤系对 RIPK 依赖性坏死敏感。我们的研究包括 RIPK3 转录如何在原代组织和转化组织中受控，以及 RIPK1 和肿瘤抑制因子 CYLD 在控制 RIPK 依赖性坏死中的作用。目标 3. RIPK 依赖性坏死是否代表一种潜在的治疗途径？许多癌症治疗方法都寻求促进细胞凋亡，这可能会也可能不会促进辅助抗肿瘤免疫。通过将信号转移到 RIPK 坏死，我们可以 a) 防止对这种死亡形式有抵抗力的组织（例如肝脏）发生医源性损伤，同时 b) 促进肿瘤细胞死亡的炎症模式。我们将模拟“纯”RIK3 诱导的坏死与细胞凋亡，以检查抗肿瘤后果，并将探索一种反直觉的方法，通过体内死亡受体连接来触发本地和移植肿瘤中的 RIPK 依赖性坏死。还将探讨肿瘤新血管系统被靶向的可能性（基于目标 1 的考虑）。这些研究为我们提出的新模型提供了许多测试和探索，并有可能大大增加对正常发育和癌症中控制生命细胞和死亡的这一基本过程的理解。