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: 9885135
• 负责人: Chen Zhao
• 金额: $ 16.12万
• 依托单位: UNIVERSITY OF IOWA
• 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 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9885135
• 关键词: Ablation; Acute Myelocytic Leukemia; Affect; Apoptosis; Biology; Biopsy Specimen; Bone Marrow Cells; Bone marrow biopsy; CD34 gene; Cell physiology; 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 proliferation; 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.

项目摘要/摘要 急性髓系白血病(AML)是由一小部分自我更新的白血病干细胞(LSCs)维持的。 定义和定位特定调控LSCs的关键分子可能会根除AML。热休克 已知转录因子1(HSF1)调节热休克蛋白(HSPs)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。尽管HSF1不是癌基因，但它能使癌细胞 为了适应信号的不平衡以及DNA、蛋白质和能量代谢的变化， 这种现象被称为“非癌基因成瘾”。在急性髓细胞白血病中靶向HSPs的探索很有希望 结果。然而，靶向HSP会导致反馈增加HSF1的活性，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选择。然而，鉴于 HSF1在维持正常细胞内稳态中的关键作用，靶向HSF1可能会对 正常的造血功能。出乎意料的是，我们的初步数据显示，HSF1对于正常来说是必不可少的 造血，但特别是LSCs自我更新所必需的。从机制上讲，删除HSF1 破坏氨基酸代谢和线粒体氧化磷酸化(OXPHOS)，这在 在调节LSC功能中的作用，以及参与LSC干性的多方面基因的失调。此外，我们 发现肝细胞核因子4a(HNF4a)是HSF1的直接靶标。HNF4a基因的高效表达 重组HSF1诱导的受损LSC功能的缺失。基于这些观察结果，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必需的 (主要是OXPHOS)，是AML的潜在治疗靶点。我们提出了以下两个具体目标 来检验我们的假设。目标1：确定特别需要HSF1的潜在机制 为了LSC的自我更新。我们将确定1)HSF1消融对LSC频率、增殖和 OXPHOS；2)综合分析转录调控基因HSF1在喉鳞状细胞中的转录靶点 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消融诱导的LSC缺陷，尤其是HNF4a对HSF1消融诱导的LSC缺陷的影响 OXPHOS上的HNF4a；以及4)如果HSF1缺失会对不同类型的AML造成机械性损害。目标2：实现 确定靶向HSF1是否有效消除人类LSC。我们将确定1)HSF1的影响 抑制人LSC的增殖、凋亡、自我更新和氧化磷酸化；2)HSF1- 3)HSF1蛋白表达与急性髓系白血病是否相关 治疗反应和复发。这一综合分析的预期结果是确定 HSF1专门调节LSC自我更新的机制，为目标提供了理论基础 HSF1和使用HSF1监测AML进展。