Investigating the Roles of Phospholipase A2s and Diacylglycerol Signaling in Ferroptosis

研究磷脂酶 A2 和二酰甘油信号在铁死亡中的作用

• 批准号: 10553721
• 负责人: Annie J Lin
• 金额: $ 5.27万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-15 至 2025-01-14
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10553721
• 关键词: ABHD12 gene; Address; BAY 54-9085; Biochemical; Biological; Biological Assay; Biological Models; CRISPR/Cas technology; Cancer cell line; Cell Death; Cell Death Induction; Cell Survival; Cells; Cessation of life; Conventional (Clear Cell) Renal Cell Carcinoma; Degenerative Disorder; Dependence; Development; Diglycerides; Dose; Drug Metabolic Detoxication; Enzymes; Equilibrium; Etiology; Event; Excision; Exhibits; Fatty Acids; Genes; Genetic; Heart; Human; In Vitro; Investigation; Iron; Isoenzymes; Lipid Peroxidation; Lipids; Lysophospholipids; Malignant Neoplasms; Mammals; Mediating; Mediator; Membrane; Modality; Molecular; Morphology; Oxidation-Reduction; Oxidative Stress Pathway; Participant; Pathway interactions; Pharmacotherapy; Phospholipase; Phospholipase A2; Phospholipids; Physiological; Play; Polyunsaturated Fatty Acids; Positioning Attribute; Predisposition; Primary carcinoma of the liver cells; Process; Protein Family; Protein Isoforms; Protein Kinase; Protein Kinase C; Reactive Oxygen Species; Reporting; Research; Role; Shapes; Signal Induction; Signal Pathway; Signal Transduction; Small Interfering RNA; Specificity; Stress; Techniques; Testing; Therapeutic; Time; Tumor Suppression; Up-Regulation; acquired drug resistance; anti-cancer; cancer cell; cancer therapy; cell type; chemotherapeutic agent; epithelial to mesenchymal transition; fibrosarcoma; glutathione peroxidase; immune checkpoint blockade; in vivo; inhibitor; kinase inhibitor; knock-down; lipid mediator; lipidome; lipidomics; molecular modeling; neoplastic cell; network models; novel; oxidative damage; protein activation; repaired; response; small hairpin RNA; small molecule; therapeutic development; therapy resistant

PROJECT SUMMARY Despite rapid advances in cancer therapeutic development, acquired drug resistance continues to threaten the long-term efficacy of existing chemotherapeutic agents, necessitating the expansion of treatment options targeting novel mechanisms to induce tumor cell death. To that end, induction of ferroptosis, a non- apoptotic, regulated cell death modality, has been shown to be a promising anti-cancer strategy. To date, ferroptosis susceptibility has been demonstrated in many cancer cell types, including clear-cell renal carcinoma and hepatocellular carcinoma25. Ferroptosis has also been shown to be involved in the therapeutic mechanism of existing therapies including sorafenib, a multi-kinase inhibitor, and immune checkpoint blockade therapy26,27,30. Furthermore, multiple studies have reported that therapy-resistant cancer cells that persist after conventional first-line drug treatments or that have undergone epithelial-to-mesenchymal transition exhibit an increased dependency on a druggable phospholipid hydroperoxidase enzyme, namely glutathione peroxidase 4 (GPX4)22-24, the central component and major inhibitor of the ferroptotic cell death pathway. Therefore, defining the molecular mechanisms governing ferroptosis will likely reveal potential targets for the development of novel cancer therapeutics. Ferroptosis is characterized by extensive lipid peroxidative damage to biological membranes that overwhelms the ability of GPX4 to detoxify these lipid reactive oxygen species, eventually leading to cell death. While the central mechanisms of this regulated cell death pathway have been elucidated, the mediators of ferroptosis susceptibility are not fully characterized and the molecular signals and events that ultimately result in cellular demise remain unknown. Our lab and others have demonstrated that widespread changes in the cellular lipidome occur during ferroptosis, characterized by the significant upregulation of lysophospholipids and certain polyunsaturated fatty acid-containing diacylglycerols (PUFA-DAGs)2-7. The mechanisms that mediate these changes and the functions they play in ferroptosis are as yet unknown. In this study, I will use small molecule dose response, genetic modulation techniques, and lipidomic profiling to investigate the role of phospholipase A2s (PLA2s, lipid remodeling enzymes that generate lysophospholipids), and PUFA-DAG signaling pathways in ferroptosis. I propose that specific phospholipase A2 enzymes (specifically, ABHD12, PLA2G15, and PLA2G10) are active in the removal of key sensitizing lipid species from the membrane and potentially in the repair of oxidatively damaged membranes during ferroptosis (Aim 1). I further propose that specific PUFA-DAGs coordinate downstream signaling cascades through activation of certain protein kinase C subtypes, which have been implicated in oxidative stress pathways15, directing the cell toward cell death (Aim 2). A tipping of the balance between these opposing processes may determine cell fate.

项目摘要 尽管癌症治疗性发育方面取得了迅速的进步，但获得的耐药性仍在继续 威胁现有化学治疗剂的长期疗效，需要扩大治疗 针对诱导肿瘤细胞死亡的新机制的选择。为此，诱导铁铁作用，一种非 - 凋亡，调节的细胞死亡方式已被证明是一种有希望的抗癌策略。迄今为止， 在许多癌细胞类型中已经证明了脂肪毒化的易感性，包括透明细胞肾癌 和肝细胞癌25。铁凋亡也已被证明参与了治疗机制 现有疗法包括索拉非尼，多激酶抑制剂和免疫检查点封锁 治疗26,27,30。此外，多项研究报告说，在 常规的一线药物治疗或经过上皮到间质转变的常规药物治疗表现出 增加对毒磷脂氢过氧化物酶的依赖性，即谷胱甘肽过氧化物酶 4（gpx4）22-24，螺旋性细胞死亡途径的中心成分和主要抑制剂。所以， 定义管理螺栓杀伤的分子机制可能会揭示出发育的潜在目标 新型癌症治疗剂。 铁凋亡的特征是对生物膜的广泛脂质过氧化损伤， GPX4淹没了这些脂质活性氧的能力，最终导致细胞死亡。 尽管已经阐明了该调节细胞死亡途径的中心机制，但 铁毒化易感性尚未完全表征，并且最终导致的分子信号和事件 在细胞中，灭亡仍然未知。我们的实验室和其他实验室表明， 细胞脂肪组发生在铁铁作用期间，其特征是溶物磷脂的显着上调 以及某些多不饱和脂肪酸的二酰基甘油（PUFA-DAGS）2-7。这些机制 介导这些变化及其在铁铁作用中发挥的功能尚不清楚。在这项研究中，我将使用 小分子剂量反应，遗传调节技术和脂质组分析，以研究 磷脂酶A2S（PLA2S，产生溶物磷脂的脂质重塑酶）和PUFA-DAG 铁凋亡中的信号通路。我提出了特定的磷脂酶A2酶（具体来说，ABHD12， PLA2G15和PLA2G10）在去除膜和 可能在氧化性损伤的膜上修复螺栓胞菌病（AIM 1）。我进一步建议 特定的pufa-dag通过激活某些蛋白激酶C的激活协调下游信号级联 亚型与氧化应激途径有关15，将细胞引导到细胞死亡（AIM 2）。这些相反过程之间平衡的倾斜可能决定细胞命运。