RIPK-dependent necrosis in development and cancer

发育和癌症中的 RIPK 依赖性坏死

• 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
• 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

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）：虽然胱天蛋白酶在细胞凋亡中的作用已得到充分确立，但对这些蛋白酶在程序性坏死过程中的作用知之甚少。该应用是基于令人震惊的发现，表明由于caspase-8的消融或其适配器蛋白FADD的消融而导致胚胎致死性，这是通过删除Ripk3完全挽救的，RIPK3是一种编程坏死所需的激酶。我们的研究表明，FADD，caspase-8和Flip的复合物是缺乏催化性半胱氨酸的胱天冬酶样分子，可预防RIPK依赖性坏死。我们的发现，FADD-FLIPK3 TKO小鼠正常发展，这进一步支持了这一点。我们提出以下研究来描述这些蛋白质在发育和癌症中的功能：AIM 1。由FADD-Caspase-8-Flipl Complect保护的发育目标是什么？ caspase-8，FADD和FLIPL敲除的表型均显示出E10.5附近的胚胎致死性，与蛋黄囊血管形成缺陷有关。在此目标中，我们将测试以下观点：血管内皮和造血细胞的早期祖细胞是这种发育缺陷的最早，最重要的靶标。这样一来，我们将确定RIPK3-链球菌的其他靶标，并研究从事这种胚胎致死性的信号传导途径。目标2。在肿瘤发生中如何调节RIPK依赖性坏死？ CASPASE-8在人类上存在于第2季度，通常在人类神经母细胞瘤，小细胞肺癌和其他癌症中被沉默或删除。然而，这代表了悖论，因为许多细胞类型中的这种损失使细胞对RIPK依赖性坏死敏感。在这里，我们探讨了caspase-8的损失如何无法使肿瘤线对RIPK依赖性坏死敏感。我们的研究包括如何在原发性组织和转化的组织中控制RIPK3转录以及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。依赖RIPK的坏死是否代表了治疗的潜在途径？许多癌症治疗方法寻求促进凋亡，这可能会或可能不会促进辅助抗肿瘤免疫。通过将信号转移到RIPK - 丝状上，我们可以a）防止对这种死亡形式的组织中的医源性损害（例如肝脏），而b）促进肿瘤细胞死亡的炎症模式。我们将模拟“纯” RIK3诱导的坏死与凋亡，以检查抗肿瘤后果，并将探索一种反直觉的方法，可通过VIVO中的死亡受体结扎型在自phistothonos and Craft肿瘤中触发RIPK依赖性坏死。还将探索肿瘤新脉管系统的目标（基于AIM 1的考虑）。这些研究提供了我们提出的新模型的许多测试和探索，并具有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的潜力。