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: 10724246
• 负责人: Gandhar Kiran Datar
• 金额: $ 5.11万
• 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/10724246
• 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; Leukemic Cell; Ligation; Maintenance; Malignant Neoplasms; Mediating; Methylation; Molecular; Mus; Mutate; Mutation; Myelogenous; Nuclear; Outcome; Pathogenesis; Pathway interactions; Patient-Focused Outcomes; Patients; Pattern; Preleukemia; 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 这项提议的首要目标是确定核磷蛋白1(NPM1)和DNA的突变 甲基转移酶3A(DNMT3A)协同调节HOX基因在急性白血病发生发展中的作用 髓系白血病(AML)。急性髓系白血病是一种血液系统恶性肿瘤，由造血系统的体细胞突变引起。 导致它们在骨髓壁龛中扩张的祖细胞。大约20,000例急性髓系白血病病例是 在美国每年确诊一次，5年存活率不到30%。NPM1和DNMT3A是 AML中最常见的突变基因，分别出现在所有病例的30%和20%。这些突变 经常共存，近70%的NPM1突变AML伴随DNMT3A突变。 总而言之，这些突变会带来更糟糕的整体预后。尽管他们已经建立了联系，但 在NPM1/DNMT3A突变同时存在的情况下，驱动强大恶性肿瘤的协同机制是 知之甚少，从而阻碍了有效靶向治疗的发展。 我们的团队和其他人已经证明，这些突变在HOx调节上收敛，其中高HOx 表达维持白血病细胞处于未分化状态。我们的团队已经证明了突变体NPM1是 AML中的Hox表达式需要。此外，DNMT3A突变与全球变化有关 在甲基化，特别是在HOX基因座。为了更好地确定突变体NPM1的机制，我进行了一种蛋白质 显示突变体NPM1与核糖体保守的生物发生-核糖体相互作用的相互作用屏幕 在HOX基因沉默中具有额外作用的复合体。我们假设，在AML发病过程中， DNMT3A突变提高了HOX基因座染色质的可及性，从而显著增加了 突变型NPM1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体NPM1增加HOX表达的机制，重点是 Rixosome在HOX基因沉默中的作用我们还将描述NPM1/DNMT3A中的HOX染色质组织 突变型急性髓系白血病的体内外研究。这项拟议的工作将揭示大多数 在急性髓系白血病中发现常见的联合突变。因此，这些研究将确定新的治疗脆弱性 NPM1/DNMT3A突变型AML为开发靶向治疗改善患者开辟了道路 结果。