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.

项目摘要/摘要 该提案的总体目标是确定核素1（NPM1）和DNA中的突变如何 甲基转移酶3A（DNMT3A）在急性发展中调节HOX基因表达 髓样白血病（AML）。 AML是由造血性突变引起的血液学恶性肿瘤 祖细胞导致它们在骨髓小裂中的扩张。大约有20,000例AML是 每年在美国诊断，其5年生存率少于30％。 NPM1和DNMT3A是 AML中最常见的突变基因，分别发生在所有情况的30％和20％中。这些突变 经常同时发生，几乎有70％的NPM1突变剂AML带有伴随的DNMT3A突变。 这些突变共同表明了整体预后更糟糕。尽管他们建立了联系，但 在两个NPM1/DNMT3A突变存在下驱动强大恶性肿瘤的协同机制是 了解不足，从而阻止了有效的靶向疗法的发展。 我们的小组和其他人表明，这些突变在HOX调节上汇合，其中高HOX 表达在未分化状态下保持白血病细胞。我们的小组表明突变的NPM1是 required for HOX expression in AML.此外，DNMT3A突变与全球变化有关 在甲基化中，特别是在Hox基因座。为了更好地定义突变NPM1的机制，我进行了蛋白质 揭示突变NPM1的相互作用屏幕与rixosom相互作用，rixosom是一种保守的核糖体生物发生 复合物在HOX基因沉默中具有其他作用。我们假设在AML发病机理期间， DNMT3A突变增强了HOX基因基因座的染色质可及性，该基因座强劲地增加了 突变体NPM1干扰Rixosom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NPM1增加HOX表达的机制，具体的重点是 Rixosom在HOX基因沉默中的作用。我们还将在NPM1/DNMT3A中表征HOX染色质组织 体外和体内突变AML。这项提出的工作将揭示最大的关键分子机制 在AML中发现的常见共突变。结果，这些研究将确定新的治疗脆弱性 NPM1/DNMT3A突变体AML，并清除开发靶向疗法以改善患者的路径 结果。