Identification of therapeutic targets in clonal hematopoiesis

克隆造血治疗靶点的鉴定

基本信息

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
项目类别：
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

项目摘要

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.

项目概要/摘要克隆造血 (CH) 的特点是血液中遗传上不同的细胞亚群的生长并且是急性髓系白血病 (AML) 的潜在前体状态。 CH 与年龄相关，发生于 20% 以上 60岁以上的人，患血液系统恶性肿瘤和心血管疾病的风险增加。这 CH 最常见的突变发生在表观遗传修饰因子 DNMT3A、TET2、ASXL1 和 IDH2 中，这些突变也相同在 AML 中发现高变异等位基因频率的突变与其作为起始突变的作用一致。 CH突变已知可诱导造血干细胞和祖细胞 (HSPC) 的功能变化；然而，具体的这些改变背后的机制尚不清楚，并且缺乏针对这些突变的基因型特异性疗法。鉴于 CH 的广泛患病率、合并症和恶变风险，存在未得到满足的需求开发可以预防克隆扩张和恶性转化的新疗法。我的长期目标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事实证明，培养原代小鼠 HSPC 是一项重大的技术挑战，无法使用公正的筛选来培养原代小鼠 HSPC。确定治疗靶点。如目标 1 中所述，我的论文工作建立了一个离体共培养系统，维持原代小鼠 HSPC，并产生与之前的小鼠和人类一致的 CH 突变表型研究。我们使用该系统对 Dnmt3a、Tet2、Asxl1 和 Idh2 突变 HSPC 进行 CRISPR/Cas9 筛选并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去甲基酶 Jmjd1c 和 Kdm3b 是在 Tet2 和 Idh2 突变 HSPC 中观察到的强依赖性。在具体目标 1.1 中，我们将询问 Jmjd1c 或 Kdm3b 的缺失与 Tet2 或 Idh2 的突变协同作用以产生表观遗传和驱动合成致死性的转录状态。在具体目标 1.2 中，我们将使用临床前小鼠模型和初级患者样本，以描绘针对 Tet2 和 Idh2 突变型 CH 的 JMJD1C 和 KDM3B 的治疗潜力反洗钱。我的博士后研究将继续研究 CH 和 AML，重点稍微转向阐明负责 CH 突变克隆的扩展和转化的潜在表观遗传和转录电路。如目标 2 中详述，我们将应用 CH 和 AML 的小鼠模型对单个 HSPC 克隆进行条形码标记，然后进行单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。全面的，这两个项目将深入了解克隆扩张和转化发生的基本机制以及寻求减轻这种克隆扩张/转化的潜在治疗策略。该提案将进行在纪念斯隆凯特琳癌症中心 (MSK) Ross Levine 博士的实验室中进行最先进的癌症研究研究所。这些隶属关系，加上格斯特纳·斯隆·凯特琳研究生院的强大资产，将提供丰富的协作、技术和科学资源来执行拟议的研究和职业发展计划。