Targeting microRNAs to eradicate leukemia stem cells

靶向 microRNA 根除白血病干细胞

• 批准号: 10202498
• 负责人: YA-HUEI KUO
• 金额: $ 49.71万
• 依托单位: BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10202498
• 关键词: Acute; Acute Myelocytic Leukemia; Acute leukemia; Allogenic; Attenuated; Biological; Blood; Bone Marrow; Cause of Death; Cell Compartmentation; Cell Cycle; Cell Maintenance; Cell Maturation; Cell Proliferation; Cells; Chronic Myeloid Leukemia; Clinical; Disease; Dose; Endothelial Cells; Equilibrium; Exposure to; Gene Expression Profile; Gene Targeting; Genes; Genetic Engineering; Health; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Homeostasis; Leukemic Cell; Leukemic Hematopoietic Stem Cell; Life; Maintenance; Malignant - descriptor; Malignant Neoplasms; Mediating; Messenger RNA; MicroRNAs; Modeling; Molecular; Molecular Cytogenetics; Molecular Target; Myelogenous; Outcome; Output; Patient-Focused Outcomes; Pharmacodynamics; Phosphorylation Site; Phosphotransferases; Plasma; Population; Prognosis; Property; Protein Tyrosine Kinase; Proteins; Recurrence; Recurrent disease; Regulation; Relapse; Reporting; Research; Resistance; Risk; Role; Sampling; Schedule; Testing; Toxic effect; Translations; Transplantation; Treatment outcome; Tyrosine Kinase Inhibitor; United States; Untranslated RNA; Up-Regulation; aging population; cell transformation; chemotherapy; chronic leukemia; effective therapy; exhaustion; gene repression; graft vs host disease; graft vs leukemia effect; improved; in vivo; inhibitor/antagonist; leukemia; leukemic stem cell; leukemogenesis; mouse model; novel; pharmacodynamic model; preclinical study; prevent; programs; resistance mechanism; self-renewal; stem cell genes; stem cell niche; stem cell therapy; stem cells; stressor; targeted agent; targeted treatment; therapeutic target; therapeutically effective; therapy resistant; treatment response

Leukemia stem cells (LSC) comprise subpopulations of cells in acute or chronic leukemia that have acquired “stem cell” properties including the ability to endure unlimited self-renewal, maintain aberrant clonal hematopoiesis and achieve quiescence upon exposure to chemotherapy or other bio-stressors thereby conferring resistance to antileukemia treatments. Currently available cell-cycle-dependent chemotherapy and other molecular targeting agents are unable to eliminate these LSCs. Thus new effective treatments to abrogate LSC are an unmet need. MicroRNAs (miRNAs) are short non-coding RNAs that regulate levels of multiple target proteins, thereby controlling a wide array of cellular programs. Among miRNAs that are deregulated in leukemia, higher expression of miR-126-3p (miR-126) is associated with LSC-gene expression signatures and poor outcome. Furthermore, higher levels of miR-126 controls quiescence both in normal hematopoietic stem cells (HSC) and LSC, but while attenuated miR-126 activity increases HSC hematopoietic output, it drives LSC to exhaustion. The central hypothesis of this proposal is that miR-126 is critical for the homeostasis of LSC and mediates LSC therapy resistance, thus represents a promising LSC-directed therapeutic target. The major objective of this application is to understand how miR-126 expression is aberrantly regulated in LSC and to develop an effective therapeutic approach to inhibit miR-126 in LSC, while sparing normal hematopoiesis. As a proof-of-principle, we will focus on targeting miR-126 in acute myeloid (AML) and chronic myeloid leukemia (CML), but similar principles could be expanded to other types of leukemia. We propose the following specific aims (SA): SA1. To dissect and overcome the molecular mechanisms of therapy resistance mediated by a newly discovered SPRED1/miR-126 autoregulatory loop in LSC. We will test that a tyrosine kinase (TK)-dependent SPRED1/miR-126 autoregulatory loop is operative in AML and CML, which mediate miR-126-dependent mechanisms of resistance to tyrosine kinase inhibitors (TKI). We will 1) assess the activity of SPRED1/miR-126 autoregulatory loop in distinct subtypes of AML; 2) define TK-dependent SPRED1 phosphorylation sites; 3) create leukemia mouse models to dissect the interplay of SPRED1/miR-126 autoregulatory loop with aberrantly active TK. SA2. To define the role of miR- 126 in maintaining a LSC niche within the bone marrow microenvironment. We will develop genetically engineered AML and CML models with conditional miR-126 deletion in LSC and endothelial cells (EC). We will determine 1) the contribution of miR-126 produced by LSC; 2) the contribution of miR-126 in the EC compartment; 3) whether deletion of miR-126 could enhance treatment-mediated elimination of LSC. SA3. To develop and optimize a synthetic inhibitor that targets miR-126 in LSC and the LSC niche. We will perform PK and PD analyses and preclinical studies to define the active dose/schedule of an antimiR-126 conjugated with CpG-oligodeoxynucleotide (ODN) for optimal targeted cell delivery.

白血病干细胞 (LSC) 包括急性或慢性白血病细胞亚群，这些细胞已获得 “干细胞”特性包括承受无限自我更新、维持异常克隆的能力 造血并在暴露于化疗或其他生物应激源时实现静止 赋予抗白血病治疗耐药性。目前可用的细胞周期依赖性化疗和 其他分子靶向剂无法消除这些 LSC。因此，新的有效治疗方法 废除 LSC 是一项未满足的需求。 MicroRNA (miRNA) 是短非编码 RNA，可调节 多个靶蛋白，从而控制多种细胞程序。在 miRNA 中， 在白血病中失调，miR-126-3p (miR-126) 的较高表达与 LSC 基因表达相关 签名和糟糕的结果。此外，较高水平的 miR-126 控制着正常情况下的静止状态。 造血干细胞 (HSC) 和 LSC，但减弱 miR-126 活性会增加 HSC 造血作用 输出，它驱动LSC耗尽。该提案的中心假设是 miR-126 对于 LSC 的稳态并介导 LSC 治疗抵抗，因此代表了一种有前途的 LSC 导向 治疗目标。本应用的主要目的是了解 miR-126 的表达是如何进行的 并开发一种有效的治疗方法来抑制 LSC 中的 miR-126，同时 不影响正常的造血功能。作为原理验证，我们将重点关注急性髓系细胞中的 miR-126 （AML）和慢性粒细胞白血病（CML），但类似的原则可以扩展到其他类型 白血病。我们提出以下具体目标（SA）：SA1。剖析并克服分子 新发现的SPRED1/miR-126自动调节介导的治疗抵抗机制 LSC 中循环。我们将测试酪氨酸激酶 (TK) 依赖性 SPRED1/miR-126 自动调节环 在 AML 和 CML 中发挥作用，介导 miR-126 依赖性酪氨酸激酶抵抗机制 抑制剂（TKI）。我们将 1) 评估 SPRED1/miR-126 自动调节环在不同亚型中的活性 反洗钱； 2) 定义TK依赖的SPRED1磷酸化位点； 3）创建白血病小鼠模型来剖析 SPRED1/miR-126 自动调节环路与异常活跃的 TK 的相互作用。 SA2。定义 miR-的作用 126 维持骨髓微环境中的 LSC 生态位。我们将通过遗传来发展 在 LSC 和内皮细胞 (EC) 中进行条件性 miR-126 缺失的工程化 AML 和 CML 模型。我们将 确定1)LSC产生的miR-126的贡献； 2) miR-126在EC中的贡献 隔间； 3) miR-126的缺失是否可以增强治疗介导的LSC消除。 SA3。到 开发并优化一种针对 LSC 和 LSC 生态位中的 miR-126 的合成抑制剂。我们将 进行 PK 和 PD 分析以及临床前研究，以确定 antimiR-126 的活性剂量/时间表 与 CpG-寡脱氧核苷酸 (ODN) 结合，以实现最佳的靶向细胞递送。