Targeting microRNAs to eradicate leukemia stem cells

靶向 microRNA 根除白血病干细胞

基本信息

批准号：
9753734
负责人：
YA-HUEI KUO
金额：
$ 45.17万
依托单位：
BECKMAN RESEARCH INSTITUTE/CITY OF HOPE
依托单位国家：
美国
项目类别：
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/9753734
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 Property Protein Tyrosine Kinase Proteins Recurrence Recurrent disease Regulation Relapse Reporting Research Resistance Risk Role Sampling Schedule Stem cells Testing Toxic effect Translations Transplantation Treatment Efficacy 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 miRNA expression profiling mouse model novel outcome forecast pharmacodynamic model preclinical study prevent programs resistance mechanism self-renewal stem cell niche stem cell therapy stressor targeted agent targeted treatment therapeutic target therapy resistant treatment response

项目摘要

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目前可用的细胞周期依赖性化疗和抗白血病治疗的耐药性。其他分子靶向药物无法消除这些 LSC，因此需要新的有效治疗方法。消除 LSC 是一种未满足的需求，MicroRNA (miRNA) 是调节 LSC 水平的短非编码 RNA。多个靶蛋白，从而控制 miRNA 中的多种细胞程序。在白血病中失调，miR-126-3p (miR-126) 的较高表达与 LSC 基因表达相关此外，在正常情况下，较高水平的 miR-126 控制着静止。造血干细胞 (HSC) 和 LSC，但减弱 miR-126 活性会增加 HSC 造血作用该提议的中心假设是 miR-126 对于 LSC 至关重要。 LSC 的稳态并介导 LSC 治疗抵抗，因此代表了一种有前途的 LSC 导向该应用的主要目的是了解 miR-126 的表达情况。并开发一种有效的治疗方法来抑制 LSC 中的 miR-126，同时作为原理验证，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我们提出以下具体目标（SA）： SA1。新发现的 SPRED1/miR-126 自动调节介导的治疗耐药机制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我们将 1) 评估 SPRED1/miR-126 自动调节环在不同亚型中的活性。 AML；2) 定义 TK 依赖性 SPRED1 磷酸化位点；3) 创建白血病小鼠模型以剖析 SPRED1/miR-126 自动调节环路与异常活跃的 TK 的相互作用。 126 在维持骨髓微环境中的 LSC 生态位方面我们将进行基因开发。我们将在 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。确定 1) LSC 产生的 miR-126 的贡献；2) miR-126 在 EC 中的贡献 3) miR-126 的缺失是否可以增强治疗介导的 SA3 消除。我们将开发和优化针对 LSC 和 LSC 生态位中的 miR-126 的合成抑制剂。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。