Heat Shock Transcription Factor 1 Specifically Regulates AML Stem Cell Self-Renewal

热休克转录因子 1 特异性调节 AML 干细胞自我更新

• 批准号: 10343855
• 负责人: Chen Zhao
• 金额: $ 39.66万
• 依托单位: CASE WESTERN RESERVE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-12-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10343855
• 关键词: Ablation; Acute Myelocytic Leukemia; Affect; Apoptosis; Biology; Biopsy Specimen; Bone Marrow Cells; Bone marrow biopsy; CD34 gene; Cells; ChIP-seq; Chromatin; Clinical Markers; DNA metabolism; Data; Defect; Development; Diffuse; Dysmyelopoietic Syndromes; Energy Metabolism; Epigenetic Process; Epithelial Cells; Feedback; Frequencies; Gene Expression; Genes; Genetic Transcription; Growth; Heat shock proteins; Hematopoiesis; Hematopoietic stem cells; Homeostasis; Human; Impairment; Knowledge; Leukemic Cell; Liver; Lymphoblastic Leukemia; MLL-AF9; Maintenance; Malignant - descriptor; Minority; Mitochondria; Modeling; Molecular; Monitor; Mus; Mutate; Myeloproliferative disease; Oncogenes; Outcome; Oxidative Phosphorylation; Pathway interactions; Patients; Play; Proteins; Relapse; Research; Role; Signal Transduction; Signaling Molecule; Solid Neoplasm; Stress; Testing; acute myeloid leukemia cell; amino acid metabolism; base; cancer cell; cell injury; chemotherapy; clinically relevant; experience; genetic manipulation; glucose metabolism; heat shock transcription factor; hepatocyte nuclear factor; improved; intestinal epithelium; leukemia; leukemic stem cell; misfolded protein; overexpression; protein metabolism; proteotoxicity; reconstitution; self-renewal; small molecule; small molecule inhibitor; stem cell function; stem cell proliferation; stem cell self renewal; stemness; success; therapeutic target; transcription factor; transcriptomics; treatment effect; treatment response; tumorigenesis

Project Summary/Abstract Acute myeloid leukemia (AML) is maintained by a small minority of self-renewing leukemic stem cells (LSCs). Defining and targeting the key molecules that specifically regulate LSCs might eradicate AML. Heat shock transcription factor 1 (HSF1) is known to regulate the expression of heat shock proteins (HSPs) to protect cells from misfolded protein-induced proteotoxic stress. Although HSF1 is not an oncogene, it enables cancer cells to accommodate imbalances in signaling and alterations in DNA, protein, and energy metabolism, a phenomenon called “non-oncogene addiction”. Targeting HSPs in AML is being explored with promising results. However, targeting HSPs induces feedback that increases HSF1 activity, which may compromise treatment effects. Therefore, targeting HSF1 directly may be a more attractive alternative. However, given the critical roles of HSF1 in the maintenance of normal cellular homeostasis, targeting HSF1 could adversely affect normal hematopoiesis. Unexpectedly, our preliminary data show that HSF1 is dispensable for normal hematopoiesis, but specifically required for the self-renewal of LSCs. Mechanistically, deletion of HSF1 disrupts amino acid metabolism and mitochondrial oxidative phosphorylation (OXPHOS), which plays a critical role in regulating LSC function, and dysregulates multifaceted genes involved in LSC stemness. In addition, we identified that hepatocyte nuclear factor 4a (HNF4a) as a direct HSF1 target. Overexpression of HNF4a largely reconstitutes deletion of HSF1-induced impaired LSC function. Based on these observations, we hypothesize that HSF1 is specifically required for LSC self-renewal through regulating leukemic energy metabolism (mainly OXPHOS) and is a potential therapeutic target in AML. We propose the following two specific aims to test our hypothesis. Aim 1: To determine the underlying mechanism whereby HSF1 is specifically required for LSC self-renewal. We will determine 1) the impact of HSF1 ablation on LSC frequencies, proliferation and OXPHOS; 2) the HSF1 transcriptional targets in LSCs by comprehensive analysis of transcriptomic gene expression, chromatin accessibility and chromatin immunoprecipitation (ChIP) sequencing in the presence or absence of HSF1; 3) how HNF4a reconstitutes HSF1 ablation-induced LSC defects, especially the effect of HNF4a on OXPHOS; and 4) if deletion of HSF1 impairs mechanistically different types of AML. Aim 2: To determine if targeting HSF1 effectively eliminate human LSCs. We will determine 1) the impact of HSF1 inhibition on human LSC proliferation, apoptosis, self-renewal and oxidative phosphorylation; 2) the HSF1- dependent regulatory circuitry in human LSCs; and 3) if the expression of HSF1 protein correlates with AML therapeutic response and relapse. The expected outcomes of this comprehensive analysis are identification of the mechanism whereby HSF1 specifically regulates LSC self-renewal, providing the rationale for targeting HSF1 and using HSF1 to monitor AML progression.

项目概要/摘要 急性髓系白血病 (AML) 由一小部分自我更新的白血病干细胞 (LSC) 维持。 定义和靶向特异性调节 LSC 的关键分子可能会根除 AML。热休克 转录因子 1 (HSF1) 已知可调节热休克蛋白 (HSP) 的表达以保护细胞 来自错误折叠的蛋白质诱导的蛋白毒性应激。虽然 HSF1 不是癌基因，但它可以使癌细胞 为了适应信号传导的不平衡以及 DNA、蛋白质和能量代谢的改变， 这种现象被称为“非癌基因成瘾”。正在探索针对 AML 中的 HSP，前景乐观 结果。然而，针对 HSP 会诱导增加 HSF1 活性的反馈，这可能会损害 治疗效果。因此，直接靶向HSF1可能是一个更有吸引力的替代方案。然而，鉴于 HSF1 在维持正常细胞稳态中的关键作用，针对 HSF1 可能会产生不利影响 正常造血功能。出乎意料的是，我们的初步数据显示HSF1对于正常情况来说是可有可无的。 造血作用，但 LSC 的自我更新特别需要。从机制上来说，HSF1 的缺失 破坏氨基酸代谢和线粒体氧化磷酸化 (OXPHOS)，这在 调节 LSC 功能，并失调参与 LSC 干性的多方面基因。此外，我们 确定肝细胞核因子 4a (HNF4a) 是 HSF1 的直接靶标。 HNF4a 过度表达 重建 HSF1 诱导的 LSC 功能受损的缺失。根据这些观察，我们假设 HSF1是LSC通过调节白血病能量代谢进行自我更新所特别需要的 （主要是 OXPHOS），是 AML 的潜在治疗靶点。我们提出以下两个具体目标 来检验我们的假设。目标 1：确定 HSF1 特别需要的根本机制 用于LSC自我更新。我们将确定 1) HSF1 消融对 LSC 频率、增殖和 氧化磷； 2）通过转录组基因综合分析LSCs中HSF1转录靶点 在存在或存在的情况下进行表达、染色质可及性和染色质免疫沉淀 (ChIP) 测序 HSF1 缺失； 3）HNF4a如何重建HSF1消融引起的LSC缺陷，特别是 OXPHOS 上的 HNF4a； 4) HSF1 的缺失是否会在机制上损害不同类型的 AML。目标 2： 确定靶向 HSF1 是否能有效消除人类 LSC。我们将确定 1) HSF1 的影响 抑制人LSC增殖、凋亡、自我更新和氧化磷酸化； 2) HSF1- 人类 LSC 中的依赖性调节电路； 3) HSF1蛋白的表达是否与AML相关 治疗反应和复发。这项综合分析的预期结果是确定 HSF1 特异性调节 LSC 自我更新的机制，为靶向提供了理论基础 HSF1 和使用 HSF1 监测 AML 进展。