Targeting Cdc42 in leukemia stem cells

靶向白血病干细胞中的 Cdc42

• 批准号: 8042683
• 负责人: JAMES C MULLOY
• 金额: $ 30.75万
• 依托单位: CINCINNATI CHILDRENS HOSP MED CTR
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-10 至 2015-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8042683
• 关键词: Actins; Acute Myelocytic Leukemia; Adhesions; Affect; Apoptosis; Back; Binding; Biochemical; Biological; Blood; Bone Marrow; CD34 gene; Cell Adhesion; Cell Maintenance; Cell Nucleus; Cell Proliferation; Cell physiology; Cells; Collection; Cytokine Signaling; Cytoskeletal Modeling; Cytoskeleton; Defect; Engraftment; Event; F-Actin; Family; Future; Gene Deletion; Gene Targeting; Genetic; Goals; Growth Factor Receptors; Guanosine Triphosphate Phosphohydrolases; Hematopoietic Stem Cell Mobilization; Hematopoietic stem cells; Homing; Human; In Vitro; Integrins; Knock-out; Lead; Leukemic Cell; MLLT3 gene; Maintenance; Malignant Neoplasms; Maps; Mediating; Methodology; Methods; Modeling; Molecular; Mus; N-ras Genes; Nodal; Pathologic; Pathway interactions; Physiological; Play; Reagent; Resistance; Retroviridae; Role; Signal Pathway; Signal Transduction; Stem cells; Stimulus; Testing; Therapeutic; Translating; Transplantation; Ursidae Family; Work; Xenograft Model; Xenograft procedure; abstracting; anti-cancer therapeutic; chemotherapy; combinatorial; inhibitor/antagonist; leukemia; leukemic stem cell; leukemogenesis; migration; mouse model; mutant; new therapeutic target; novel; novel therapeutics; progenitor; reconstitution; residence; response; rho; rho GTP-Binding Proteins; small hairpin RNA; stem; therapeutic target

Abstract The goals of this project are to use genetic means to demonstrate that the Rho GTPase, Cdc42 constitutes a novel target in leukemia stem cells (LSCs), and to apply a lead pharmacologic inhibitor of Cdc42 to suppress deregulated Cdc42 activity in human blood stem cell malignancies. The Cdc42 signaling axis lies at the crossroads of many signaling events and the functional interaction between Cdc42 and many of its implicated effectors mediate a variety of physiological responses including actin cytoskeletal reorganization, adhesion, migration, survival, and proliferation, of blood stem/progenitor cells. Cdc42 has been suggested to mediate Ras-transformation by signaling through growth factor receptors and to transduce cytokine signals into the nucleus to impact on cell proliferation. In the preliminary results, we have built up a basic conceptual framework suggesting that Cdc42 targeting can inhibit leukemia stem cell adhesion and engraftment, promote LSC mobilization from the bone marrow, and induce LSC apoptosis, in mouse models. We have also generated and established a collection of important reagents, mouse models, and methodologies including a conditional gene targeted mouse model, a human stem/progenitor transformed acute myeloid leukemia xenograft model in "humanized" mice, a lead Cdc42-activity specific inhibitor, CASIN, that is capable of specifically suppressing Cdc42 activity in blood progenitors, and Cdc42 mutant reconstitution/xenotransplantation add-back methods in defining the requirement of immediate signaling pathways regulated by Cdc42. In this proposal, we will test the hypothesis that Cdc42 is essential for the maintenance of LSCs in the BM niche and represents a novel therapeutic target for leukemia eradication. We will (1) genetically validate Cdc42 as a target in murine AML onset and progression by conditional gene targeting and mutant reconstitution approaches; (2) determine the effect and molecular mechanisms of Cdc42 knockdown on human AML progression in a humanized mouse model; and (3) apply the Cdc42-specific inhibitor, CASIN, to mobilization of human AML leukemia stem cells from xenograft mouse bone marrow and examine the combinatorial effect of CASIN together with the conventional chemotherapy agents on AML leukemia stem cell eradication. Our studies may implicate Cdc42 as a critical nodal of intracellular signal flows from multiple stimuli involved in leukemia stem cell maintenance in the bone marrow niche. The results will bear direct therapeutic value that pharmacologic targeting of Cdc42 in LSCs may allow for more effective combinatory chemotherapy in the effort to eradicate leukemia.

抽象的 该项目的目标是使用遗传手段来证明Rho GTPase， CDC42构成白血病干细胞（LSC）的新靶标，并应用铅 CDC42的药理学抑制剂可抑制人体血液中失控的CDC42活性 干细胞恶性肿瘤。 CDC42信号轴位于许多信号的十字路口 事件及其cdc42及其许多涉及效应子之间的功能相互作用 调解各种生理反应，包括肌动蛋白细胞骨架重组， 血管/祖细胞的粘附，迁移，存活和增殖。 Cdc42具有 建议通过通过生长因子发出信号来介导RAS转化 受体并将细胞因子信号传递到细胞核中以影响细胞增殖。 在初步结果中，我们建立了一个基本的概念框架，表明 CDC42靶向可以抑制白血病干细胞粘附和植入，促进LSC 小鼠模型中的骨髓动员并诱导LSC凋亡。我们有 还生成并建立了重要试剂，鼠标模型和 方法学包括有条件基因靶向小鼠模型，人类 茎/祖先在“人性化”小鼠中转化的急性髓样白血病模型， 铅cdc42活动特异性抑制剂赌场，能够特别抑制 Cdc42血液祖细胞的活性和CDC42突变体重建/异种移植 在定义立即信号通路的需求时，添加背包方法 由CDC42。在此提案中，我们将检验以下假设：Cdc42对于 在BM利基市场中维护LSC，代表了一个新颖的治疗靶点 消除白血病。我们将（1）遗传验证Cdc42作为鼠AML中的靶标 通过条件基因靶向和突变重建方法的发作和进展； （2）确定CDC42敲低对人AML的影响和分子机制 人性化小鼠模型的进展； （3）应用Cdc42特异性抑制剂， 赌场，从异种移植小鼠骨骼动员人类AML白血病干细胞 骨髓并检查赌场的组合效应与常规 AML白血病干细胞消除的化学疗法。我们的研究可能意味着 Cdc42是来自涉及多个刺激的细胞内信号流的临界节点 骨髓小裂中的白血病干细胞维持。结果将直接 LSC中CDC42的药理靶向的治疗价值可能允许更多 有效的组合化疗努力消除白血病。