Identification of therapeutic targets in clonal hematopoiesis

克隆造血治疗靶点的鉴定

• 批准号: 10528774
• 负责人: Michael R Waarts
• 金额: $ 4.83万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10528774
• 关键词: ATAC-seq; Acute Myelocytic Leukemia; Address; Age; Aging; Bar Codes; Biological; Blood; Bone Marrow; CRISPR screen; Cardiovascular Diseases; Cardiovascular system; Cells; Clinical; Clonal Expansion; Clone Cells; Coculture Techniques; DNMT3a; Dependence; Development; Development Plans; Endothelial Cells; Epigenetic Process; Event; Future; Gene Frequency; Genetic; Genetic Transcription; Genotype; Hematologic Neoplasms; Hematopoiesis; Hematopoietic stem cells; High Prevalence; Histones; Human; Individual; Individual Differences; Induced Mutation; Investigation; Laboratories; Lysine; Malignant - descriptor; Mediating; Memorial Sloan-Kettering Cancer Center; Minority Groups; Molecular; Mus; Mutation; Patients; Phenotype; Prevalence; Process; Recurrence; Reporting; Research; Research Institute; Research Personnel; Research Project Grants; Resources; Risk; Role; Sampling; Schools; System; Technical Expertise; Testing; Therapeutic; Work; anticancer research; career; career development; chemical genetics; comorbidity; fitness; genetic variant; human data; in vivo; inhibitor; insight; interest; knowledge base; mortality; mouse model; mutant; novel; novel therapeutics; pre-clinical; prevent; recombinase; research and development; response; self-renewal; single-cell RNA sequencing; stem cell function; therapeutic target; transcriptomics

PROJECT SUMMARY/ABSTRACT Clonal hematopoiesis (CH) is characterized by the outgrowth of a genetically distinct subpopulation of cells in the blood and is a potential precursor state to acute myeloid leukemia (AML). CH is age-associated, occurring in over 20% of individuals over age 60, and confers an increased risk of both hematological malignancy and cardiovascular disease. The most common mutations in CH occur in the epigenetic modifiers DNMT3A, TET2, ASXL1, and IDH2 and these same mutations are found at high variant allele frequencies in AML consistent with their role as initiating mutations. CH mutations are known to induce functional changes in hematopoietic stem and progenitor cells (HSPCs); however, the specific mechanisms underlying these alterations are not understood and genotype-specific therapies for these mutations are lacking. Given the broad prevalence, comorbidities, and risk of malignant transformation associated with CH, there is an unmet need to develop novel therapies that can prevent clonal expansion and malignant transformation. The long-term objective of my doctoral research is to identify genotype-specific therapeutic targets in CH. To date, the lack of a suitable ex vivo platform for culturing primary murine HSPCs has proved a significant technical challenge preventing the use of unbiased screens to identify therapeutic targets. As described in Aim 1, my thesis work has established an ex vivo co-culture system that maintains primary murine HSPCs and that yields phenotypes of CH mutations consistent with prior murine and human studies. We have used this system to perform CRISPR/Cas9 screens on Dnmt3a-, Tet2-, Asxl1-, and Idh2-mutant HSPCs and have identified genotype-specific dependencies. Of particular interest, the histone lysine demethylases Jmjd1c and Kdm3b are strong dependencies observed in Tet2- and Idh2-mutant HSPCs. In Specific Aim 1.1, we will interrogate the mechanisms by which loss of Jmjd1c or Kdm3b cooperates with mutations in Tet2 or Idh2 to create an epigenetic and transcriptional state that drives synthetic lethality. In Specific Aim 1.2, we will use preclinical murine models and primary patient samples to delineate the therapeutic potential of targeting JMJD1C and KDM3B in Tet2 and Idh2-mutant CH and AML. My postdoctoral research will continue to study CH and AML with a slight switch in focus to elucidating the underlying epigenetic and transcriptional circuitry responsible for the expansion and transformation of CH-mutant clones. As detailed in Aim 2, we will apply murine models of CH and AML to barcode individual HSPC clones followed by single- cell transcriptomic and epigenetic studies to define the factors that allow for clonal expansion and transformation. Overall, these two projects will offer insights into both the basic mechanisms by which clonal expansion and transformation occur and potential therapeutic strategies seeking to mitigate this clonal expansion/transformation. This proposal will be conducted in the laboratory of Dr. Ross Levine at Memorial Sloan Kettering Cancer Center (MSK), a state-of-the-art cancer research institute. These affiliations, along with the strong assets of the Gerstner Sloan Kettering Graduate School, will provide a rich set of collaborative, technical, and scientific resources to execute the proposed research and career development plans.

项目总结/摘要 克隆性造血（CH）的特征是血液中遗传上不同的细胞亚群的生长 并且是急性髓性白血病（AML）的潜在前体状态。CH与年龄相关，发生在超过20%的 在60岁以上的个体中，这类疾病的发生率较高，并且血液恶性肿瘤和心血管疾病的风险增加。的 CH中最常见的突变发生在表观遗传修饰物DNMT 3A、TET 2、ASXL 1和IDH 2中，并且这些相同的 突变在AML中以高变异等位基因频率发现，这与它们作为起始突变的作用一致。CH突变 已知诱导造血干细胞和祖细胞（HSPC）的功能变化;然而， 这些改变的潜在机制尚不清楚，并且缺乏针对这些突变的基因型特异性疗法。 鉴于CH的广泛患病率、合并症和恶性转化风险， 开发新的治疗方法，可以防止克隆扩张和恶性转化。我的长期目标是 博士研究的目的是确定CH的基因型特异性治疗靶点。迄今为止，缺乏合适的离体平台， 已经证明，对于培养原代鼠HSPC， 确定治疗靶点。如目标1所述，我的论文工作建立了一个离体共培养系统， 维持原代鼠HSPC，并产生与先前鼠和人HSPC一致的CH突变表型。 问题研究我们已经使用该系统对Dnmt 3a-、Tet 2-、Asxl 1-和Idh 2-突变型HSPC进行CRISPR/Cas9筛选 并且已经确定了基因型特异性依赖性。特别令人感兴趣的是，组蛋白赖氨酸脱甲基酶Jmjd 1c和 Kdm 3b是Tet 2和Idh 2突变型HSPC中观察到的强依赖性。在具体目标1.1中，我们将询问 Jmjd 1c或Kdm 3b的缺失与Tet 2或Idh 2中的突变合作产生表观遗传和 转录状态驱动合成致命性。在具体目标1.2中，我们将使用临床前小鼠模型和原代小鼠模型。 患者样本，以描绘Tet 2和Idh 2突变CH中靶向JMJD 1C和KDM 3B的治疗潜力， 急性髓细胞白血病我的博士后研究将继续研究CH和AML，重点略有转移，以阐明 负责CH-突变克隆的扩增和转化的潜在表观遗传和转录电路。 如目的2中所详述，我们将应用CH和AML的鼠模型对单个HSPC克隆进行条形码化，然后进行单克隆测序。 细胞转录组学和表观遗传学研究，以确定允许克隆扩增和转化的因素。总的来说， 这两个项目将提供对克隆扩张和转化发生的基本机制的深入了解 以及寻求减轻这种克隆扩增/转化的潜在治疗策略。这项提案将在 在纪念斯隆凯特琳癌症中心（MSK）的罗斯·莱文博士的实验室里， 院这些附属机构，沿着的Gerstner斯隆凯特琳研究生院的强大资产，将提供一个 丰富的协作，技术和科学资源，以执行拟议的研究和职业发展计划。