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.

项目概要/摘要 该提案的首要目标是确定核磷蛋白 1 (NPM1) 和 DNA 中的突变如何 甲基转移酶 3A (DNMT3A) 在急性炎症发展中协同调节 HOX 基因表达 骨髓性白血病（AML）。 AML是一种由造血系统体细胞突变引起的血液系统恶性肿瘤 导致其在骨髓生态位中扩张的祖细胞。大约有 20,000 例 AML 病例 在美国每年都会被诊断出来，5年生存率不到30%。 NPM1 和 DNMT3A 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 经常同时发生，近 70% 的 NPM1 突变 AML 伴有伴随的 DNMT3A 突变。 总之，这些突变导致整体预后更差。尽管他们建立了协会， 在 NPM1/DNMT3A 突变存在的情况下驱动强恶性肿瘤的协同机制是 人们对其知之甚少，从而阻碍了有效靶向治疗的开发。 我们的团队和其他人已经表明，这些突变集中在 HOX 调节上，其中高 HOX 表达使白血病细胞维持在未分化状态。我们的小组已经证明突变体 NPM1 是 AML 中 HOX 表达所必需的。此外，DNMT3A突变与全球变化有关 甲基化，特别是 HOX 位点。为了更好地定义突变型 NPM1 的机制，我对蛋白质进行了研究 相互作用筛选显示突变型 NPM1 与核糖体（一种保守的核糖体生物发生）相互作用 复合物在 HOX 基因沉默中具有额外的作用。我们假设，在 AML 发病机制中， DNMT3A 突变增强了 HOX 基因位点的染色质可及性，从而大大提高了 突变体 NPM1 干扰核糖体介导的 HOX 基因沉默的能力。为了检验这个假设， 我们将首先确定突变体 NPM1 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 NPM1/DNMT3A 中的 HOX 染色质组织 体外和体内突变的 AML。这项拟议的工作将揭示最重要的关键分子机制 AML 中常见的共突变。因此，这些研究将发现新的治疗漏洞 NPM1/DNMT3A突变AML为开发靶向治疗改善患者扫清道路 结果。