The Role of BCL2 Mediated Calcium Signaling in Leukemia Stem Cell Metabolism

BCL2 介导的钙信号传导在白血病干细胞代谢中的作用

• 批准号: 10230859
• 负责人: Anagha Inguva
• 金额: $ 5.1万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10230859
• 关键词: Acute Myelocytic Leukemia; Address; Affect; Animals; BCL2 gene; Biological Assay; Biological Models; Biology; Calcium; Calcium Binding; Calcium Channel; Calcium Channel Binding; Calcium Channel Inhibition; Calcium Signaling; Cell Death; Cell Survival; Cell physiology; Cellular Metabolic Process; Citric Acid Cycle; Data; Dependence; Disease; Disease Progression; Disease remission; Engraftment; Enzymes; Genetic; Genus Hippocampus; Hematologic Neoplasms; Homeostasis; Human; ITPR1 gene; Immune; Immunocompromised Host; Isocitrate Dehydrogenase; Jordan; Ketoglutarate Dehydrogenase Complex; Link; Maps; Mass Spectrum Analysis; Mediating; Membrane; Metabolic; Metabolism; Mitochondria; Molecular; Molecular Genetics; Movement; Mus; Outcome; Oxidative Phosphorylation; Pathway interactions; Patients; Pharmaceutical Preparations; Pharmacology; Pharmacotherapy; Population; Production; Proteins; Reaction; Regulation; Relapse; Resistance; Role; Sampling; Signal Transduction; Small Interfering RNA; Specimen; Stem Cell Development; Structure-Activity Relationship; Testing; Therapeutic; Therapeutic Agents; Transplantation; Work; base; cancer stem cell; cell killing; cell type; chemotherapy; effective therapy; enzyme activity; experimental study; hematopoietic stem cell differentiation; improved; inhibitor/antagonist; knock-down; leukemic stem cell; metabolomics; mortality; novel; novel therapeutic intervention; novel therapeutics; overexpression; pyruvate dehydrogenase; release of sequestered calcium ion into cytoplasm; response; self renewing cell; standard of care; stem cell biology; stem cell population; tool; uptake

PROJECT SUMMARY The objective of this study is to define the molecular mechanisms that control survival of malignant stem cells in acute myeloid leukemia (AML). Acute myeloid leukemia (AML) is a hematologic malignancy characterized by poorly differentiated hematopoietic stem cells (25). Traditionally, outcomes have been poor with a 30% response rate to standard of care in patients 65 years and older (25,26). A large cause of resistance and relapse to therapy is the persistence of leukemia stem cells (LSCs) (27-30). LSCs are a population of self-renewing cells that are able to initiate and maintain disease in immune-compromised animals (27). Traditional chemotherapy agents do not efficiently eradicate LSCs, and development of more effective therapies is a significant unmet need (27-30). Previous work from the Jordan lab has shown that LSCs have a unique dependence on oxidative phosphorylation (OXPHOS) for energy production (1-3,24). Further, BCL2 has a non-canonical role in regulating LSC metabolism as inhibition of BCL2 led to decreased OXPHOS and subsequent cell death in primary human LSCs (1-3,24). Analysis of samples from AML patients treated with the BCL2 inhibitor drug venetoclax revealed direct targeting of LSCs, which correlated with a 70% response rate (3). Thus, the underlying premise of the current proposal is that BCL2-mediated control of OXPHOS represents a key vulnerability that can be exploited to selectively target LSCs. Further, determining how OXPHOS is inhibited through BCL2 has implications for improving therapeutic strategies for AML patients. This proposal aims to elucidate the mechanistic link between BCL2 and LSC OXPHOS. In several model systems, BCL2 has been shown to have a non-canonical function in influencing calcium uptake and release at the ER and mitochondria through direct interactions with membrane bound calcium channels (7). Intracellular calcium homeostasis is crucial for cell survival, signaling and metabolism. In particular, the three rate limiting enzymes of the TCA cycle, pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase and isocitrate dehydrogenase are calcium dependent reactions (7). Therefore, BCL2 mediated calcium movement between the ER and mitochondria could be a mechanistic link between BCL2 and OXPHOS activity. BCL2 modulates the activity of calcium channels at the ER and mitochondria differently, based on the cell type being studied (7). Therefore, my proposal is focused on determining how BCL2 modulates OXPHOS activity by regulating calcium channel biology in leukemia stem cells. My hypothesis is that BCL2 mediated calcium localization is a critical regulator of OXPHOS activity in leukemia stem cells. This proposal will determine whether 1) BCL2 mediates calcium channel biology in LSCs 2) calcium channel biology modulates LSC metabolism/function and 3) regulation of calcium localization is the mechanism of action of BCL2 inhibition in LSCs.

项目概要 本研究的目的是确定控制恶性干细胞存活的分子机制 急性髓系白血病（AML）中的细胞。急性髓系白血病（AML）是一种血液系统恶性肿瘤，其特征是 由分化不良的造血干细胞引起 (25)。传统上，结果很差，只有 30% 65 岁及以上患者对标准护理的反应率 (25,26)。耐药和复发的一个重要原因 治疗的关键在于白血病干细胞 (LSC) 的持续存在 (27-30)。 LSC 是一群自我更新的细胞 能够在免疫受损的动物中引发和维持疾病 (27)。传统化疗 药物不能有效根除 LSC，开发更有效的疗法是一个重大未满足的问题 需要（27-30）。 Jordan 实验室之前的工作表明，LSC 对氧化有独特的依赖性 磷酸化 (OXPHOS) 用于能量生产 (1-3,24)。此外，BCL2 在调节中具有非典型作用。 抑制 BCL2 导致 LSC 代谢减少 OXPHOS 并随后导致原代人类细胞死亡 LSC (1-3,24)。对接受 BCL2 抑制剂药物 Venetoclax 治疗的 AML 患者样本的分析显示 直接针对 LSC，这与 70% 的响应率相关 (3)。因此，基本前提是 目前的建议是，BCL2 介导的 OXPHOS 控制代表了一个可以利用的关键漏洞 选择性地瞄准LSC。此外，确定 OXPHOS 如何通过 BCL2 被抑制具有重要意义 改善 AML 患者的治疗策略。 该提案旨在阐明 BCL2 和 LSC OXPHOS 之间的机制联系。在多个型号中 系统中，BCL2 已被证明在影响钙的吸收和释放方面具有非典型功能。 通过与膜结合钙通道的直接相互作用来调节 ER 和线粒体 (7)。细胞内 钙稳态对于细胞生存、信号传导和代谢至关重要。特别是三项限速 TCA 循环酶、丙酮酸脱氢酶、α-酮戊二酸脱氢酶和异柠檬酸 脱氢酶是钙依赖性反应 (7)。因此，BCL2 介导钙在 ER 和线粒体可能是 BCL2 和 OXPHOS 活性之间的机制联系。 BCL2 调节 根据所研究的细胞类型，内质网和线粒体的钙通道活性有所不同 (7)。 因此，我的建议重点是确定 BCL2 如何通过调节钙来调节 OXPHOS 活性 白血病干细胞的通道生物学。我的假设是 BCL2 介导的钙定位是 白血病干细胞中 OXPHOS 活性的关键调节因子。该提案将确定是否 1) BCL2 介导 LSC 中的钙通道生物学 2) 钙通道生物学调节 LSC 代谢/功能和 3）钙定位的调节是LSCs中BCL2抑制的作用机制。