Investigating the Role of DNMT3A mutations in the initiation and maintenance of myeloid malignancies

项目摘要/摘要 急性髓系白血病(AML)是一种侵袭性的恶性肿瘤，预后很差，部分原因是 肿瘤内的遗传异质性使特定的亚克隆能够逃避甚至是密集的化疗。基因组学 研究已经确定了AML的频繁突变谱，并提出了一种顺序突变模式 收购。早期突变被认为赋予干细胞或祖细胞进行克隆的适应性优势。 在这个正在扩张的亚克隆中的扩张和后来的突变可能会带来增殖优势，从而导致 明显的恶毒。AML可以从头开始发生，但也可能发展为骨髓增生异常综合征患者 (MDS)或克隆性造血(CH)。在这些疾病状态中，DNMT3A突变是关键的启动因素 突变，这表明有机会瞄准这些恶性肿瘤的创始克隆。然而，目标是 DNMT3A突变仍然难以捉摸，因为对这些突变的机制和具体作用缺乏了解(S) 疾病中的突变。 本提案的目的是阐明两种常见的DNMT3A的特定致癌机制 突变并确定其在CH、MDS和AML维持中的功能贡献。我们假设 野生型DNMT3A的遗传恢复将阻止DNMT3A突变体CH/MDS/AML的进展，从而 针对启动的DNMT3A突变可以为髓系疾病提供一种治疗选择。此外，一个 完全了解DNMT3A突变将有助于识别有针对性的漏洞 由这些突变所赋予。特定目标1将利用可诱导的小鼠模型和体外CRISPR屏幕 定义两个不同的DNMT3A突变的表型、机制和已知的脆弱性 蛋白质的功能结构域。《特定目标2》将使用能够开启的双重组小鼠模型 和DNMT3A突变以确定DNMT3A突变体CH的可逆性并评价致癌性 MDS/AML患者DNMT3A突变的相关性研究这些研究的意义将导致新的治疗方法。 DNMT3A突变恶性肿瘤的治疗方法。 这项提案将在罗斯·莱文博士(发起人)的实验室进行，他是 分子癌症医学计划。莱文实验室是人类肿瘤学和病理学计划的一部分 在纪念斯隆·凯特琳癌症中心(MSK)，一家最先进的癌症研究机构。师徒关系将 还将由MSK表观遗传学中心主任Kristian Helin博士(共同赞助者)提供。 这些关系，以及Gerstner Sloan Ketling强大的科学和非科学资产 研究生院将提供一套丰富的协作、技术和科学资源来执行 建议的研究和职业发展。

PROJECT SUMMARY/ABSTRACT Acute myeloid leukemia (AML) is an aggressive malignancy with a poor prognosis, owing in part to substantial intratumor genetic heterogeneity that allows specific subclones to evade even intensive chemotherapy. Genomic studies have identified the spectrum of frequent mutations in AML and suggest a model of sequential mutational acquisition. Early mutations are believed to confer a fitness advantage to a stem or progenitor cell enabling clonal expansion and later mutations within this expanding subclone may confer a proliferative advantage resulting in overt malignancy. AML can occur de novo, but may also develop in patients with myelodysplastic syndrome (MDS) or clonal hematopoiesis (CH). Across these disease states, DNMT3A mutations are critical initiating mutations, suggesting an opportunity to target the founding clone of these malignancies. However, targeting of DNMT3A mutations remains elusive due to a poor understanding of the mechanisms and specific role(s) of these mutations in disease. The objective of this proposal is to elucidate the specific oncogenic mechanisms of two frequent DNMT3A mutations and to define their functional contributions in the maintenance of CH, MDS, and AML. We hypothesize that genetic restoration of wildtype DNMT3A will block progression of DNMT3A-mutant CH/MDS/AML and thus that targeting the initiating DNMT3A mutations can provide a therapeutic option in myeloid disease. Moreover, a complete understanding of DNMT3A mutations will allow for the identification of targetable vulnerabilities conferred by these mutations. Specific Aim 1 will utilize inducible mouse models and ex vivo CRISPR screens to define the phenotypes, mechanisms, and conferred vulnerabilities of two DNMT3A mutations in distinct functional domains of the protein. Specific Aim 2 will use dual recombinase murine models capable of turning on and off DNMT3A mutations to determine the reversibility of DNMT3A-mutant CH and to evaluate the oncogenic dependency of DNMT3A mutations in MDS/AML. The implications of these studies will lead to novel therapeutic approaches for DNMT3A-mutant malignancies. This proposal will be conducted in the laboratory of Dr. Ross Levine (the Sponsor), who is the head of the Molecular Cancer Medicine program. The Levine lab is part of the Human Oncology and Pathogenesis Program at Memorial Sloan Kettering Cancer Center (MSK), a state of the art cancer research institute. Mentorship will also be provided by Dr. Kristian Helin (the Co-Sponsor), who is the head of the Center for Epigenetics at MSK. These affiliations, along with the strong scientific and non-scientific 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.