The role of Pleckstrin-2 as a functional node in myeloid proliferation

Pleckstrin-2 作为功能节点在骨髓增殖中的作用

• 批准号: 10208952
• 负责人: Peng Ji
• 金额: $ 48.59万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-07-09 至 2024-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10208952
• 关键词: Acute Myelocytic Leukemia; Anemia; Binding; Binding Proteins; Biochemical; Biological Assay; Blood Cell Count; Blood Cells; Blood Vessels; Blood coagulation; Bone Marrow Diseases; Bone Marrow Transplantation; Cells; Clinical Trials; Complex; Data; Development; Drug resistance; Erythropoietin; FDA approved; Foundations; Funding; Future; Goals; Hematopoiesis; Hematopoietic; Hemorrhagic Thrombocythemia; In Vitro; Infiltration; Injections; JAK2 gene; Knock-in; Knock-in Mouse; Knock-out; Knockout Mice; Lead; Membrane; Modeling; Molecular; Mus; Mutation; Myelogenous; Myeloid Cells; Myeloproliferation; Myeloproliferative disease; Names; Neutrophilia; Pathogenesis; Pathway interactions; Patients; Pharmaceutical Chemistry; Phenotype; Philadelphia Chromosome; Phosphatidylinositols; Phosphorylation; Polycythemia Vera; Primary Myelofibrosis; Production; Protein Dephosphorylation; Publishing; Reticulocytosis; Risk; Role; Sampling; Scaffolding Protein; Signal Transduction; Spleen; Splenomegaly; Stat5 protein; Testing; Therapeutic; Thrombocytopenia; Thrombosis; Toxic effect; Work; base; driver mutation; effective therapy; genetic approach; high throughput screening; in silico; in vivo; in vivo Model; inhibitor/antagonist; insight; mouse genetics; mouse model; new therapeutic target; novel; novel strategies; novel therapeutic intervention; overexpression; phosphatidylinositol 3,4,5-triphosphate; platelet protein P47; pre-clinical; recruit; side effect; small molecule inhibitor; thrombocytosis; transplant model

PROJECT SUMMARY Myeloproliferative neoplasms (MPNs) are a group of bone marrow diseases that show excessive myeloid cell production with an increased risk of developing thrombosis and evolving to acute myeloid leukemia. V617F driver mutation of JAK2 is one of the leading causes of MPNs. The discovery of this mutation led to the development of JAK inhibitors to treat MPNs. However, JAK inhibitors are not curative. In addition, MPN patients treated with JAK inhibitor often develop drug resistance and severe side effects due to the indispensable roles of JAK2 in normal hematopoiesis. We have been studying new approaches to treat MPNs, especially focusing on the downstream effectors of the JAK2 pathway. Our recently published studies funded by the current R01 revealed that loss of Pleckstrin-2 (Plek2), a novel target of the JAK2-STAT5 pathway, ameliorated JAK2V617F-induced myeloproliferative phenotypes, and more importantly reverted vascular occlusions and lethality of the JAK2V617F MPN mouse model. Given the significance of Plek2 in MPN pathogenesis, we have identified lead compounds of Plek2 small molecule inhibitors using in silico-based high- throughput screenings and cell-based assays. Our novel unpublished preliminary data further reveal that Plek2 binds to several PI3K effectors and loss of Plek2 reduces Akt activation. Preliminary in vivo evidence also demonstrates that Plek2 is critical for the PI3K-Akt pathway in that Plek2 knockout ameliorated myeloproliferation and significantly extended the survival of Pten hematopoietic specific knockout mice. These findings lead us to hypothesize that Plek2 functions as a central hub to connect the JAK2-STAT and the PI3K- Akt pathways and promote myeloproliferation. To test this hypothesis and investigate the mechanism of function of Plek2, we will use 1) in vitro biochemical and molecular studies to determine how Plek2 enhances the PI3K-Akt signaling, 2) Pten hematopoietic specific knockout mouse model to reveal the functions of Plek2 in vivo, and 3) pre-clinical MPN models and MPN patient samples to establish the efficacy of Plek2 inhibitors. Successful completion of this project will lead to novel insights into the role of Plek2 in the pathogenesis of MPNs and lay the foundation for clinical trials using Plek2 inhibitors as single agents or in combination with other compounds to treat MPNs.

项目摘要 骨髓增生性肿瘤（MPN）是一组骨髓疾病，显示出过多的髓样细胞 产生血栓形成并发展为急性髓样白血病的风险增加。 v617f JAK2的驱动突变是MPN的主要原因之一。这种突变的发现导致 开发JAK抑制剂以治疗MPN。但是，JAK抑制剂无法治愈。另外，MPN 接受JAK抑制剂治疗的患者通常会由于 JAK2在正常造血作用中必不可少的作用。我们一直在研究治疗MPN的新方法， 特别是专注于JAK2途径的下游效应器。我们最近发表的研究资助 当前的R01揭示了Pleckstrin-2（Plek2）的损失，这是JAK2-STAT5途径的新目标， 改善JAK2V617F诱导的骨髓增生性表型，更重要的是恢复的血管 JAK2V617F MPN小鼠模型的闭塞和致死性。鉴于PLEK2在MPN中的重要性 发病机理，我们已经鉴定了使用基于硅基的高 - 吞吐量筛选和基于细胞的测定。我们的小说未发表的初步数据进一步表明Plek2 与几个PI3K效应子结合，而PLEK2的丧失可降低Akt激活。初步体内证据 证明plek2对于PLEK2敲除中的PI3K-AKT途径至关重要 骨髓增生并显着扩大了PTEN造血特异性敲除小鼠的存活。这些 调查结果使我们假设PLEK2是连接JAK2-Stat和PI3K-的中心枢纽 AKT途径并促进骨髓增生。检验这一假设并研究 PLEK2的功能，我们将使用1）体外生化和分子研究来确定PLEK2如何增强 PI3K-AKT信号传导，2）PTEN造血特异性基因敲除小鼠模型，以揭示Plek2的功能 体内和3）临床前MPN模型和MPN患者样品以确定PLEK2抑制剂的功效。 成功完成该项目将导致对Plek2在发病机理中的作用的新见解 MPN和使用PLEK2抑制剂作为单个药物或与之结合的临床试验基础 其他治疗MPN的化合物。