Targeting beta1 integrin in JAK2V617F+ stem cells

靶向 JAK2V617F 干细胞中的 β1 整合素

• 批准号: 10575092
• 负责人: Shinobu Matsuura
• 金额: $ 12.38万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-12-15 至 2024-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10575092
• 关键词: ANXA5 gene; Actins; Acute Myelocytic Leukemia; Address; Adult; Animals; Antibodies; Apoptosis; Applications Grants; Blood; Blood Cells; Bone Marrow; CD29 Antigen; Caspase; Cell Adhesion Molecules; Cell Cycle; Cell Death; Cell Death Induction; Cell Differentiation Induction; Cell Maintenance; Cells; Cytoskeleton; Data; Development; Disease; Disease Progression; Disease remission; Environment; Flow Cytometry; Goals; Hematologic Neoplasms; Hematopoietic; Hematopoietic Stem Cell Mobilization; Hematopoietic stem cells; Human; Induction of Apoptosis; Integrin Inhibition; Integrin-mediated Cell Adhesion Pathway; Integrins; Intravenous; JAK2 gene; Laboratories; Leukemic Cell; Maintenance; Measures; Mediator; Megakaryocyte Proliferation; Megakaryocytes; Mentored Research Scientist Development Award; Molecular Target; Mus; Mutation; Myelofibrosis; Myeloproliferative disease; Organism; Outcome; Patients; Persons; Predisposition; Primary Myelofibrosis; Production; Proliferating; Publications; Relapse; Reporting; Research; Role; Signal Transduction; Source; Splenomegaly; Symptoms; Therapeutic; Transgenic Mice; United States; Work; cancer stem cell; cancer therapy; career; driver mutation; experimental study; extracellular; improved; in vivo; inhibitor; innovation; intraperitoneal; leukemic stem cell; mouse model; new therapeutic target; stem cells; success; therapeutic development; tositumomab

PROJECT SUMMARY/ABSTRACT The major shortcoming of current cancer therapies is the inability to target the leukemic stem cells, despite initial success in eliminating the bulk of leukemic cells. Primary myelofibrosis (PMF) belongs to the group of myeloproliferative neoplasms (MPNs), the fourth most prevalent hematological malignancy. In the United States, ~100,000 people are living with or in remission from MPNs. The most frequent driver mutation is JAK2V617F. JAK2 inhibitor ruxolitinib remarkably alleviates constitutive symptoms, but does not prolong survival or reverse disease, which progresses to myelofibrosis or transforms to acute myeloid leukemia. Mouse models and patient data suggest that this shortcoming is due to its inability to target the JAK2V617F+ stem cell. This application addresses the urgent need to develop treatments that specifically target JAK2V617F+ stem cells to improve the long-term outcome of current therapies. Previous work on the SERCA K01 award revealed de-regulated expression of integrins, adhesion molecules that integrate the extracellular environment with the actin cytoskeleton, in megakaryocytes of JAK2V617F transgenic mice and PMF patients. The central hypothesis of this proposal is that 1 integrin is a key mediator of JAK2V617F+ stem cell maintenance in PMF. In our most recent preliminary studies, we found higher activation of 1 integrin in stem cells of JAK2V617F transgenic mice compared to wild-type (WT) controls. Treatment with an anti-1 integrin inhibitory antibody HM1-1 in vivo was able to dramatically reduce the number of JAK2V617F+ stem cells, with negligible effect on WT animals. However, it is critical to understand what makes the JAK2V617F+ stem cells particularly susceptible to 1 integrin inhibition, and whether the stem cell reduction persists long-term. AIM 1 of this proposal, of mechanistic significance, will define how the anti-1 integrin antibody HM1-1 reduces JAK2V617F+ stem cells in vivo, by addressing two hypotheses: 1) that induction of cell cycle leads JAK2V617F+ stem cells to exit quiescence and differentiate, and 2) that HM1-1 induces apoptosis and cell death in JAK2V617F+ stem cells. AIM 2, of translational significance, will address the hypothesis that JAK2V617F+ stem cell reduction upon HM1-1 treatment persists long-term, and will lead to reduction of all progeny derived from JAK2V617F+ stem cells. Studies will be performed on JAK2V617F transgenic mice, carrying the human mutation, using state-of-art flow cytometric analysis of hematopoietic stem cells. Importantly, despite its essential role in organism development, conditional deletion of 1 integrin in hematopoietic cells of adult mice did not affect blood cell production or maintenance of stem cells. In contrast, as our data suggest, JAK2V617F+ stem cells seem to be particularly dependent on integrin signaling and highly sensitive to its inhibition, offering a possible therapeutic opportunity window. This proposal addresses the unmet need of identifying a molecular target specific to JAK2V617F+ stem cells with potential for therapeutic development. The AIMS of the proposal will provide important preliminary data which will serve as a basis for mechanistic studies to be proposed in an ensuing R01 grant application in support of applicant’s independent research career.

项目总结/摘要 目前的癌症疗法的主要缺点是不能靶向白血病干细胞，尽管最初的治疗是针对白血病干细胞的。 成功地清除了大量的白血病细胞。原发性骨髓纤维化（PMF）属于 骨髓增生性肿瘤（MPN），第四大流行的血液恶性肿瘤。在美国， 约有10万人患有MPN或处于缓解期。最常见的驱动突变是JAK 2 V617 F。JAK2 抑制剂ruxolitinib显著减轻组成性症状，但不延长生存期或逆转疾病， 其发展为骨髓纤维化或转化为急性髓性白血病。小鼠模型和患者数据 这表明该缺点是由于其不能靶向JAK 2 V617 F+干细胞。本申请涉及 迫切需要开发特异性靶向JAK 2 V617 F+干细胞的治疗方法，以改善长期的 目前治疗的结果。先前关于SERCA K 01奖的工作揭示了 整合素，将细胞外环境与肌动蛋白细胞骨架整合的粘附分子， JAK 2 V617 F转基因小鼠和PMF患者的巨核细胞。这一提议的核心假设是， JAK 1整合素是PMF中JAK 2 V617 F+干细胞维持的关键介质。在我们最近的初步研究中， 我们发现JAK 2 V617 F转基因小鼠的干细胞中整合素β 1的活化程度高于野生型小鼠。 对照在体内用抗-β 1整联蛋白抑制抗体HM β 1-1治疗能够显著降低 JAK 2 V617 F+干细胞的数量，对WT动物的影响可忽略不计。然而，关键是要了解 是什么使JAK 2 V617 F+干细胞特别容易受到JAK 1整联蛋白抑制，以及干细胞是否 减少将长期存在。本提案的目的1，具有机械意义，将定义如何抗干扰1 整联蛋白抗体HM 101 -1通过解决两个假设在体内减少JAK 2 V617 F+干细胞：1）诱导 细胞周期的变化导致JAK 2 V617 F+干细胞退出静止期并分化，2）HM β 1-1诱导JAK 2 V617 F+干细胞凋亡， JAK 2 V617 F+干细胞的凋亡和细胞死亡。目的2，翻译的意义，将解决的假设 在HM 101 -1治疗后JAK 2 V617 F+干细胞减少持续长期，并将导致所有细胞的减少。 来自JAK 2 V617 F+干细胞的后代。研究将在JAK 2 V617 F转基因小鼠上进行，携带 人类突变，使用最先进的造血干细胞流式细胞术分析。重要的是，尽管 在机体发育中的重要作用，成年小鼠造血细胞中整合素β 1的条件性缺失 不影响血细胞的生成或干细胞的维持。相比之下，正如我们的数据显示，JAK 2 V617 F + 干细胞似乎特别依赖于整联蛋白信号传导，并且对它的抑制高度敏感， 可能的治疗机会窗口。该提案解决了鉴定分子的未满足的需要， 特异性靶向JAK 2 V617 F+干细胞，具有治疗开发潜力。该提案的目标将 提供了重要的初步数据，这些数据将作为拟在 随后的R 01资助申请，以支持申请人的独立研究生涯。