Defining the Synergistic Role of NPM1 and DNMT3A Mutations on HOX Gene Regulation in the Pathogenesis of Acute Myeloid Leukemia

确定 NPM1 和 DNMT3A 突变对 HOX 基因调控在急性髓系白血病发病机制中的协同作用

• 批准号: 10536092
• 负责人: Gandhar Kiran Datar
• 金额: $ 4.71万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10536092
• 关键词: Acetylation; Acute Myelocytic Leukemia; Adult; Adult Acute Myeloblastic Leukemia; Animals; Binding; Biogenesis; Biological Assay; Bone Marrow; Cell Line; ChIP-seq; Chromatin; Chromatin Structure; Complex; DNA; DNA Modification Methylases; DNMT3a; DNMT3a mutation; Data; Development; Diagnosis; Epigenetic Process; Feedback; Fluorescent in Situ Hybridization; Gene Expression; Gene Expression Regulation; Gene Silencing; Genes; Global Change; Goals; Hematologic Neoplasms; Hematopoiesis; Hematopoietic stem cells; Heterochromatin; Histones; Homeobox Genes; Immunofluorescence Immunologic; In Vitro; Individual; Knock-out; Lead; Leukemic Cell; Ligation; Maintenance; Malignant Neoplasms; Mediating; Methylation; Molecular; Mus; Mutate; Mutation; Myelogenous; Nuclear; Outcome; Pathogenesis; Pathway interactions; Patient-Focused Outcomes; Patients; Pattern; Prognosis; Proteins; Publishing; Regulation; Reporting; Ribosomes; Role; Somatic Mutation; Testing; Transposase; Undifferentiated; United States; Update; Variant; Work; acute myeloid leukemia cell; chromatin immunoprecipitation; epigenetic regulation; experimental study; genomic locus; high risk; histone modification; improved; in vivo; insight; leukemia; leukemogenesis; mouse model; mutant; novel therapeutics; nucleophosmin; prevent; protein protein interaction; relapse risk; response; synergism; targeted treatment

Project Summary/Abstract The overarching goal of this proposal is to determine how mutations in Nucleophosmin 1 (NPM1) and DNA Methyltransferase 3A (DNMT3A) cooperatively regulate HOX gene expression in the development of acute myeloid leukemia (AML). AML is a hematological malignancy arising from somatic mutations in hematopoietic progenitor cells that lead to their expansion in the bone marrow niche. Approximately 20,000 cases of AML are diagnosed annually in the United States, with a 5-year survival of less than 30%. NPM1 and DNMT3A are the most frequently mutated genes in AML, occurring in 30% and 20% of all cases, respectively. These mutations frequently co-occur, with nearly 70% of NPM1-mutant AML harboring a concomitant DNMT3A mutation. Together, these mutations confer a worse overall prognosis. Despite their established association, the synergistic mechanisms that drive robust malignancy in the presence of both NPM1/DNMT3A mutations are poorly understood, thus preventing the development of effective targeted therapies. Our group and others have shown that these mutations converge on HOX regulation, where high HOX expression maintains leukemic cells in an undifferentiated state. Our group has shown that mutant NPM1 is required for HOX expression in AML. Moreover, DNMT3A mutations have been associated with global changes in methylation, particularly at HOX loci. To better define the mechanism of mutant NPM1, I performed a protein interaction screen that revealed mutant NPM1 interacts with the rixosome, a conserved ribosomal biogenesis complex with additional roles in HOX gene silencing. We hypothesize that, during AML pathogenesis, DNMT3A mutations enhance chromatin accessibility at HOX gene loci, which robustly increases the ability of mutant NPM1 to interfere with rixosome-mediated HOX gene silencing. To test this hypothesis, we will first determine the mechanism of increased HOX expression by mutant NPM1, with specific focus on the rixosome’s role in HOX gene silencing. We will also characterize HOX chromatin organization in NPM1/DNMT3A mutant AML in vitro and in vivo. This proposed work will reveal key molecular mechanisms underlying the most common co-mutations found in AML. As a result, these studies will identify new therapeutic vulnerabilities in NPM1/DNMT3A mutant AML and clear a path for the development of targeted therapies to improve patient outcomes.

项目总结/摘要 这项提案的首要目标是确定核磷酸蛋白1（NPM 1）和DNA中的突变如何影响细胞的功能。 甲基转移酶3A（DNMT 3A）协同调节HOX基因表达在急性胰腺炎发生中的作用 骨髓性白血病（AML）。AML是由造血干细胞中的体细胞突变引起的血液恶性肿瘤。 导致其在骨髓小生境中扩增的祖细胞。大约有20，000例AML病例 在美国，每年确诊的患者中，5年生存率不到30%。NPM 1和DNMT 3A是 AML中最常见的突变基因，分别占所有病例的30%和20%。这些突变 通常同时发生，近70%的NPM 1突变型AML携带伴随的DNMT 3A突变。 总之，这些突变赋予更差的总体预后。尽管他们建立了联系， 在两种NPM 1/DNMT 3A突变的存在下驱动强烈恶性肿瘤的协同机制是 人们对此知之甚少，从而阻碍了有效靶向治疗的发展。 我们的研究小组和其他人已经表明，这些突变集中在HOX调控上，其中高HOX 表达维持白血病细胞处于未分化状态。我们的研究小组已经表明，突变型NPM 1是 AML中HOX表达所必需的。此外，DNMT 3A突变与全球变化有关， 甲基化，特别是HOX基因座。为了更好地定义突变NPM 1的机制，我进行了蛋白质 相互作用筛选揭示了突变型NPM 1与rixosome相互作用，rixosome是一种保守的核糖体生物发生 复合物在HOX基因沉默中具有额外的作用。我们假设，在AML发病过程中， DNMT 3A突变增强了HOX基因位点的染色质可及性，这有力地增加了HOX基因的表达。 突变体NPM 1干扰rixosome介导的HOX基因沉默的能力。为了检验这一假设， 我们将首先确定突变型NPM 1增加HOX表达的机制，特别关注 rixosome在HOX基因沉默中的作用我们还将表征NPM 1/DNMT 3A中的HOX染色质组织 在体外和体内的突变AML。这项拟议的工作将揭示最重要的分子机制 AML中常见的共突变。因此，这些研究将确定新的治疗弱点， NPM 1/DNMT 3A突变型AML并为靶向治疗的发展扫清道路，以改善患者的 结果。