Differentiation-Dependent Targeting of Glycosylated Polyketides in Clonal Hematopoietic Disorders

项目总结/摘要 小分子构成了我们的临床治疗工具箱的基础， 用于研究生物系统的探针。然而，由于缺乏细胞类型， 选择性的细胞亚群负责疾病。这对于用于治疗的化合物尤其如此。 血液癌症，其中大多数是靶向快速分裂细胞的天然产物衍生物-包括 癌细胞和健康的造血细胞，在健康个体中产生3x 1011个新血 细胞每天这种方法的另一个限制是抗增殖疗法不能消除肿瘤细胞的增殖。 相对静止的白血病干细胞（LSC），其在治疗中存活并且通常导致复发。我们集团 最近发现，土壤细菌产生的两个家族的糖基化聚酮化合物 拟诺卡氏菌FU-40对急性髓系白血病患者中发现的不同细胞亚群表现出惊人的选择性。 白血病（AML）。西罗米星似乎对未成熟的髓系白血病细胞具有选择性细胞毒性 和白血病干细胞，而雷公藤甲素选择性地靶向成熟淋巴细胞。我们假设这 代表造血细胞在成熟-分化依赖的确定阶段的选择性靶向 面向.拟议的项目将评估这些化合物在正常和非正常细胞中的相对细胞类型选择性。 异常造血，并试图确定其观察到的选择性的分子基础。在目标1中，我们 研究西罗米星和阿托瑞林选择性靶向发育定义的程度 造血细胞亚群在我们合作者的帮助下，我们将使用质谱仪全面地 描述健康造血、骨髓增生异常综合征（MDS）和急性骨髓增生异常综合征（AML）患者的造血层次结构。 骨髓性白血病（AML），以及它是如何受到干扰的治疗与西罗米星和阿托罗定。在目标2中， 将尝试使用亲和纯化结合来鉴定西罗米星和阿托内酯的靶标， 定量蛋白质组学这种方法有可能调和观察到的雷公藤甲素的选择性 与他们报告的机制，这仍然是一个悬而未决的问题，在外地，并将提供第一个深入 西罗霉素作用机制的研究。正如这些化合物诱导的表型所示， 它们能够选择性地靶向导致疾病的细胞亚群，这项研究可能会定义 了解和治疗克隆性造血疾病的新靶点。总之，这些目标将提供一个 全面了解糖基化聚酮化合物在单细胞和 分子分辨率，同时为我提供理想的培训和指导环境， 作为一名物理学家和科学家。

Project Summary / Abstract Small molecules form the foundation of our toolbox of clinically used therapeutics as well as chemical probes for studying biological systems. However, their applications can be complicated by a lack of cell-type selectivity for the cell subsets responsible for disease. This is particularly true of compounds used to treat hematologic cancers, most of which are natural product derivatives that target rapidly dividing cells – including both cancerous cells and healthy hematopoietic cells, which in healthy individuals generate 3x1011 new blood cells each day. An additional limitation of this approach is that antiproliferative therapies fail to eliminate the relatively quiescent leukemic stem cells (LSCs), which survive therapy and often lead to recurrence. Our group recently discovered that two families of glycosylated polyketides compounds produced by the soil bacteria Nocardiopsis FU-40 exhibit striking selectivity for distinct subsets of cells found in patients with acute myeloid leukemia (AML). The ciromicins appears to be selectively cytotoxic towards immature myeloid leukemia cells and leukemic stem cells, while the apoptolidins selectively target mature lymphocytes. We hypothesize that this represents selective targeting of hematopoietic cells at defined stages of maturation – differentiation dependent targeting. The proposed project will assess the relative cell-type selectivity of these compounds in normal and abnormal hematopoiesis and attempt to define the molecular basis of their observed selectivity. In Aim 1, we will investigate the extent to which the ciromicins and apoptolidins selectively target developmentally defined hematopoietic cell subsets. With the help of our collaborators, we will use mass-cytometry to comprehensively characterize the hematopoietic hierarchy in healthy hematopoiesis, myelodysplastic syndrome (MDS), and acute myeloid leukemia (AML), and how it is perturbed by treatment with the ciromicins and apoptolidins. In Aim 2, we will attempt to identify the target(s) of the ciromicins and apoptolidins using affinity purification coupled to quantitative proteomics. This approach has the potential to reconcile the observed selectivity of the apoptolidins with their reported mechanism which remains an open question in the field, and will provide the first in depth study of the mechanism of action of the ciromicins. As the phenotype induced by these compounds suggests that they are capable of selectively targeting the subsets of cells responsible for disease, this study may define new targets for understanding and treating clonal hematopoietic disorders. Together, these aims will provide a comprehensive understanding of the mechanism of action of glycosylated polyketides at both single cell and molecular resolution, while simultaneously providing an ideal training and mentorship environment for my development as a physician-scientist.