Identification of therapeutic targets in clonal hematopoiesis

克隆造血治疗靶点的鉴定

• 批准号: 10673915
• 负责人: Michael R Waarts
• 金额: $ 4.77万
• 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/10673915
• 关键词: ATAC-seq; Acute Myelocytic Leukemia; Age; Aging; Bar Codes; Biological; Blood; Bone Marrow; CRISPR screen; Cardiovascular Diseases; Cardiovascular system; Cells; Chemicals; Clinical; Clonal Expansion; Clone Cells; Coculture Techniques; Credentialing; 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; Postdoctoral Fellow; Prevalence; Process; Recurrence; Reporting; Research; Research Institute; Research Personnel; Research Project Grants; Resources; Risk; Role; Sampling; System; Technical Expertise; Testing; Therapeutic; Work; anticancer research; career; career development; comorbidity; fitness; genetic variant; graduate school; human data; in vivo; inhibitor; insight; interest; knowledge base; mortality; mouse model; mutant; novel; novel therapeutics; permissiveness; 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.

项目摘要/摘要 克隆造血（CH）的特征是血液中细胞的遗传学亚群的生长 并且是急性髓样白血病（AML）的潜在前体状态。 CH是与年龄相关的，发生在20％以上 60岁以上的个人，并赋予血液学恶性肿瘤和心血管疾病的风险增加。这 CH中最常见的突变发生在表观遗传修饰剂DNMT3A，TET2，ASXL1和IDH2中，这些相同 在AML的高变异等位基因频率下发现突变与它们作为启动突变的作用一致。 CH突变 已知会诱导造血茎和祖细胞（HSPC）的功能变化；但是，具体 这些改变的机制尚不清楚，并且缺乏针对这些突变的基因型特异性疗法。 鉴于与CH相关的广泛流行，合并症和恶性转化的风险，有未满足的需求 开发可以防止克隆扩张和恶性转化的新型疗法。我的长期目标 博士研究是为了确定CH中的基因型特异性治疗靶标。迄今为止，缺乏合适的离体平台 用于培养主要的鼠hspcs已证明是一项重大的技术挑战，阻止了使用公正的屏幕 确定治疗靶标。如AIM 1所述，我的论文工作已经建立了一个离体共文化系统 维持原发性鼠HSPC，并产生与先前的鼠和人类一致的CH突变的表型 研究。我们已经使用该系统在DNMT3A-，TET2-，ASXL1-和IDH2突变HSPC上执行CRISPR/CAS9屏幕 并已经确定了基因型特异性依赖性。特别有趣的是，组蛋白赖氨酸脱甲基酶JMJD1C和 KDM3B是在TET2-和IDH2突变HSPC中观察到的强依赖性。在特定的目标1.1中，我们将审问 JMJD1C或KDM3B的损失与TET2或IDH2中的突变合作以创建表观遗传和 驱动合成致死性的转录状态。在特定的目标1.2中，我们将使用临床前鼠模型和主要 患者样本描述靶向tet2和idh2突变ch和kdm3b的治疗潜力 AML。我的博士后研究将继续研究CH和AML，并以稍微转换为重点以阐明 基础表观遗传和转录电路负责CH突变克隆的扩展和转化。 如AIM 2所述，我们将在条形码单个HSPC克隆中应用CH和AML的鼠模型，然后是单个单个的 细胞转录组和表观遗传学研究，以定义允许克隆扩张和转化的因素。全面的， 这两个项目将提供有关克隆扩张和转化的基本机制的见解 以及寻求减轻克隆扩张/转化的潜在治疗策略。该提议将进行 在最先进的癌症研究 研究所。这些隶属关系，以及Gerstner Sloan Kettering研究生院的强大资产，将提供一个 丰富的合作，技术和科学资源，以执行拟议的研究和职业发展计划。