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: 10328253
• 负责人: Annie J Lin
• 金额: $ 4.68万
• 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/10328253
• 关键词: ABHD12 gene; Address; BAY 54-9085; Biochemical; Biological; Biological Assay; Biological Models; CRISPR/Cas technology; Cancer cell line; Cell Death; 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; Mediating; Mediator of activation protein; Membrane; Membrane Potentials; Modality; Molecular; Morphology; Oxidation-Reduction; Oxidative Stress; Oxides; Participant; Pathway interactions; Peroxides; Pharmacotherapy; Phospholipase; Phospholipase A2; Phospholipids; Physiological; Play; Polyunsaturated Fatty Acids; Positioning Attribute; Predisposition; Process; Protein Family; Protein Isoforms; Protein Kinase; Protein Kinase C; Reactive Oxygen Species; Reporting; Research; Role; Shapes; 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; 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.

项目概要 尽管癌症治疗的发展取得了快速进展，但获得性耐药性仍在继续 威胁现有化疗药物的长期疗效，需要扩大治疗范围 针对诱导肿瘤细胞死亡的新机制的选择。为此，诱导铁死亡，一种非 细胞凋亡、受调节的细胞死亡方式已被证明是一种有前途的抗癌策略。迄今为止， 铁死亡易感性已在许多癌细胞类型中得到证实，包括透明细胞肾癌 和肝细胞癌25。铁死亡也被证明参与了治疗机制 现有疗法，包括索拉非尼（一种多激酶抑制剂）和免疫检查点阻断 治疗26,27,30。此外，多项研究报告称，治疗后仍存在耐药性的癌细胞 传统的一线药物治疗或已经经历上皮间质转化的药物治疗表现出 对可药物磷脂氢过氧化物酶（即谷胱甘肽过氧化物酶）的依赖性增加 4 (GPX4)22-24，铁死亡细胞死亡途径的核心成分和主要抑制剂。所以， 定义控制铁死亡的分子机制可能会揭示开发的潜在目标 新的癌症疗法。 铁死亡的特点是生物膜发生广泛的脂质过氧化损伤， 压倒 GPX4 解毒这些脂质活性氧的能力，最终导致细胞死亡。 虽然这种受调节的细胞死亡途径的中心机制已被阐明，但 铁死亡的易感性尚未完全表征，最终导致的分子信号和事件 细胞死亡中的作用仍然未知。我们的实验室和其他实验室已经证明， 细胞脂质组发生在铁死亡过程中，其特征是溶血磷脂显着上调 以及某些含有多不饱和脂肪酸的二酰基甘油 (PUFA-DAG)2-7。的机制 介导这些变化，并且它们在铁死亡中发挥的功能尚不清楚。在本研究中，我将使用 小分子剂量反应、遗传调节技术和脂质组学分析来研究 磷脂酶 A2（PLA2，产生溶血磷脂的脂质重塑酶）和 PUFA-DAG 铁死亡中的信号通路。我建议特定的磷脂酶 A2 酶（特别是 ABHD12、 PLA2G15 和 PLA2G10) 具有从膜上去除关键敏化脂质的活性， 潜在地修复铁死亡过程中氧化损伤的细胞膜（目标 1）。我进一步建议 特定的 PUFA-DAG 通过激活某些蛋白激酶 C 来协调下游信号级联 亚型，与氧化应激途径15有关，引导细胞走向细胞死亡（目的 2）。这些相反过程之间的平衡的倾斜可能决定细胞的命运。