Genetic modulators of erythro-megakaryocytic development

编码转录因子加塔-1基因的体细胞突变与急性胰腺炎相关 巨核细胞白血病（AMKL）的儿童唐氏综合征（DS，三体21），虽然 这种遗传相互作用的机制尚不清楚。在初步研究中，我证明， 21三体本身增加了人红细胞和巨核细胞祖细胞的增殖能力。 在小鼠的平行研究中，我使用了基因操作的胚胎干细胞，以显示 加塔-1促进双能巨核细胞-红系前体细胞（MEP）的扩增， 类似于AMKL爆炸通过突变型MEP的基因互补，我发现， 加塔-1抑制骨髓分化的程序，部分是通过抑制原核细胞的转录， 癌基因PU.1/Sfpi 1。AMKL相关的GATA 1突变减弱了这种作用。一起我的 研究结果产生了两个相关的假设：首先，GATA 1突变和21三体产生不同的影响， 对造血系统的影响，它们共同作用促进白血病。其次，加塔-1推动常态化 通过抑制PU.1/Sfpi 1转录来抑制造血，并且该过程可能变得失调 通过与DS-AMKL相关的遗传改变。此应用程序是为了支持一个指导研究 阐明加塔-1如何控制正常造血以及调控失调的加塔-1和 DS在白血病发生中有协同作用。我将扩展我在DS胎儿造血的研究，以了解 21三体扩增红系和巨核细胞祖细胞的机制（Aim 1）。我会 研究人类造血系统中改变的加塔-1和21三体之间的功能相互作用 体外和小鼠中的祖细胞（目的2）。最后，我将研究野生型和 AMKL相关的加塔-1突变体抑制PU。1/SfpH癌基因转录（Aim 3）。如果 成功，我的研究将提供见解的转录控制正常的肾上腺皮质激素， 巨核细胞的发育以及该过程如何在AMKL中受到干扰。的广泛影响 这项研究是为了更好地了解谱系特异性转录因子在正常组织中的功能， 发展和癌症。结合我在此应用程序中的培训和结构化指导， 我相信，这项研究将为正常和恶性肿瘤提供新的见解， 造血，并提供了坚实的基础，建立我的职业生涯作为一个儿科医生，科学家。

Somatic mutations in the gene encoding transcription factor GATA-1 are associated with acute megakaryoblastic leukemia (AMKL) in children with Down syndrome (DS, trisomy 21), although the mechanisms underlying this genetic interaction are unknown. In preliminary studies, I demonstrated that trisomy 21 itself increases the proliferative capacity of human erythroid and megakaryocyte progenitors. In parallel murine studies, I used genetically manipulated embryonic stem cells to show that loss of GATA-1 promotes the expansion of bipotential megakaryocyte-erythroid precursors (MEPs), a population that resembles AMKL blasts. Through genetic complementation of the mutant MEPs, I discovered that GATA-1 represses a program of myeloid differentiation, in part by inhibiting transcription of the proto- oncogene PU.1/Sfpi1. This effect is attenuated by AMKL-associated GATA1 mutations. Together, my findings generate two related hypotheses: First, GATA1 mutations and trisomy 21 produce distinct effects on hematopoiesis, which act together to promote leukemia. Second, GATA-1 promotes normal hematopoiesis by repressing PU.1/Sfpi1 transcription and this process may become dysregulated through genetic alterations associated with DS-AMKL. This application is to support a mentored research experience to elucidate how GATA-1 controls normal hematopoiesis and how dysregulated GATA-1 and DS synergize in leukemogenesis. I will extend my studies in DS fetal hematopoiesis to understand the mechanisms by which trisomy 21 expand erythroid and megakaryocytic progenitors (Aim 1). I will examine functional interactions between altered GATA-1 and trisomy 21 in human hematopoietic progenitors in vitro and in mice (Aim 2). Lastly, I will study the mechanisms by which wild type and AMKL-associated mutant forms of GATA-1 repress PU. 1/SfpH oncogene transcription (Aim 3). If successful, my research will provide insights into the transcriptional control of normal erythro- megakaryocytic development and how this process becomes disturbed in AMKL. The broader impact of this research is to better understand how a lineage-specific transcription factor functions in normal tissue development and cancer. Combined with my training and structured mentoring in this application, I believe that the proposed research will provide novel new insights into normal and malignant hematopoiesis and provide a strong foundation to establish my career as a pediatric physician-scientist.