Crosstalk between leukemic blasts and the BM microenvironment contribute to leukemic transformation

白血病原始细胞和骨髓微环境之间的串扰有助于白血病转化

• 批准号: 10446917
• 负责人: Adrienne M. Dorrance
• 金额: $ 36.85万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-04 至 2027-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10446917
• 关键词: Acute Myelocytic Leukemia; Antibodies; Binding; Biology; Blast Cell; Blocking Antibodies; Blood; Bone Diseases; Bone Marrow; Cell Line; Cell physiology; Cells; Chromosome abnormality; Clinical; Combined Modality Therapy; Cytogenetics; DNA Sequence Alteration; Data; Disease; Epithelial; Exhibits; FLT3 gene; FLT3 inhibitor; Feedback; Frequencies; Genetic; Goals; Growth; Growth Factor; Hematological Disease; Hematopoietic Neoplasms; Hematopoietic stem cells; In Vitro; Knockout Mice; Leukemic Cell; Malignant - descriptor; Malignant Neoplasms; Marrow; Messenger RNA; Modeling; Molecular; Molecular Cytogenetics; Monoclonal Antibodies; Mus; Mutate; Mutation; Myelogenous; Patients; Phenotype; Physiological; Play; Process; Prognosis; Proteins; Publishing; Recombinants; Relapse; Reporting; Resistance; Role; Sampling; Series; Signal Pathway; Signal Transduction Pathway; Testing; Therapeutic; Work; acute myeloid leukemia cell; antileukemic activity; autocrine; base; cell growth; clinical development; cohort; conditional knockout; efficacy evaluation; endothelial stem cell; experimental study; in vivo; leukemia; leukemia initiating cell; leukemic stem cell; leukemic transformation; leukemogenesis; mRNA Expression; mesenchymal stromal cell; mouse model; novel; novel therapeutics; paracrine; patient derived xenograft model; pre-clinical; preclinical study; response; stem cell function; therapeutic target; therapy resistant

PROJECT SUMMARY Acute myeloid leukemia (AML) is a clonal, highly heterogeneous malignancy of the blood and bone marrow with poor prognosis. Along with genetic mutations within the leukemic cells themselves, alterations in the BM microenvironment (BMM) also play an important role in leukemia transformation, therapy resistance, and relapse. Thus, to develop effective AML therapies, it is critical to understand how intrinsic genetic alterations in the leukemic blasts cooperate with the BMM to facilitate leukemogenesis. We identified that the secreted protein Epithelial Growth Factor Like 7 (EGFL7) is highly expressed in a large cohort of AML patients and is associated with poor prognosis. We further demonstrate that: 1) EGFL7 protein increases blast cell growth and impacts on leukemic stem cell (LSC) function; 2) leukemic bone marrow mesenchymal stromal cells (MSCs) express and secrete EGFL7 at increased levels compared to normal MSCs ; 3) normal MSCs exhibit increased growth and survival in response to a recombinant EGFL7 protein and 4) Egfl7 is increased in AML blasts, but not in pre- leukemic hematopoietic stem and progenitor cells (HSPCs) from a primary Mll PTD; Flt3 ITD murine AML model. Based on our work, we hypothesize that aberrant EGFL7 expression by leukemic cells and BM niche cells contribute to leukemogenesis and is a relevant target for treatment for AML patients. The goal of our proposal is to fully characterize the phenotypic contributions of EGFL7 to myeloid leukemogenesis, dissect its molecular mechanism(s), and determine the therapeutic benefit of targeting EGFL7 in AML. We are planning to achieve these goals through the following specific aims (SA): SA#1: To demonstrate the importance of EGFL7 in leukemic cells to alter the BM microenvironment to promote leukemogenesis. Here, we hypothesize that EGFL7 promotes a positive feedback loop between leukemic cells and the BM microenvironment contributing to disease initiation and progression. We will test this hypothesis with a series of in vitro and in vivo experiments organized in three tasks. In Task 1 we will examine the contribution of EGFL7 in the BMM towards the initiation of AML using our Mll PTD; Flt3 ITD and Egfl7fl/fl conditional knock-out mouse models. For Task 2 we will determine how alterations in the expression of EGFL7 effects MSCs in leukemogenesis. Task 3 we will characterize the molecular mechanisms of Egfl7-dependent signaling pathways in MSCs; SA#2: To investigate anti-leukemic activity of a monoclonal EGFL7 blocking antibody (Parsatuzumab) in combination with a FLT3 inhibitor (Gilteritinib), using patient derived xenograft (PDX) murine models and primary genetic murine models of AML. Here, we propose to conduct in vitro and in vivo preclinical studies using AML cell lines, primary AML samples and two murine models of FLT3 mutated AML to evaluate the efficacy of targeting the autocrine and paracrine action of EGFL7 in AML. Overall, this proposal seeks to define the role of EGFL7 in the cross-talk between the BMM and leukemic cells and to generate preclinical data to support clinical development of anti-EGFL7 monoclonal antibodies in combination with FLT3 inhibitors for FLT3 mutated AML.

项目概要 急性髓系白血病 (AML) 是一种克隆性、高度异质性的血液和骨髓恶性肿瘤， 预后不良。除了白血病细胞本身的基因突变之外，骨髓的改变 微环境（BMM）在白血病转化、治疗耐药和白血病转化中也发挥着重要作用。 复发。因此，为了开发有效的 AML 疗法，了解内在的基因改变是如何进行的至关重要。 白血病原始细胞与 BMM 合作促进白血病发生。我们发现分泌的蛋白质 上皮生长因子样 7 (EGFL7) 在一大群 AML 患者中高度表达，并且与 预后不良。我们进一步证明：1) EGFL7 蛋白增加母细胞生长并影响 白血病干细胞（LSC）功能； 2) 白血病骨髓间充质基质细胞 (MSC) 表达和 与正常 MSC 相比，EGFL7 的分泌水平更高； 3) 正常 MSC 表现出生长加快 重组 EGFL7 蛋白的存活率和 4) Egfl7 在 AML 母细胞中增加，但在预治疗中没有增加 来自原代 Mll PTD 的白血病造血干细胞和祖细胞 (HSPC)； Flt3 ITD 小鼠 AML 模型。 根据我们的工作，我们假设白血病细胞和骨髓微环境细胞异常表达 EGFL7 有助于白血病发生，是 AML 患者治疗的相关靶点。我们提案的目标是 为了充分表征 EGFL7 对髓系白血病发生的表型贡献，剖析其分子 机制，并确定靶向 EGFL7 在 AML 中的治疗益处。我们计划实现 通过以下具体目标 (SA) 实现这些目标： SA#1：证明 EGFL7 在 白血病细胞改变骨髓微环境以促进白血病发生。在这里，我们假设 EGFL7 促进白血病细胞和导致疾病的骨髓微环境之间的正反馈循环 启动和进展。我们将通过一系列体外和体内实验来检验这一假设 在三项任务中。在任务 1 中，我们将检查 BMM 中 EGFL7 对 AML 启动的贡献 使用我们的 Mll PTD； Flt3 ITD 和 Egfl7fl/fl 条件敲除小鼠模型。对于任务 2，我们将确定如何 EGFL7 表达的改变影响 MSC 的白血病发生。任务 3 我们将描述 MSCs中Egfl7依赖性信号通路的分子机制； SA#2：研究抗白血病作用 单克隆 EGFL7 阻断抗体 (Parsatuzumab) 与 FLT3 抑制剂联合使用的活性 （Gilteritinib），使用患者衍生的异种移植（PDX）小鼠模型和 AML 的原代遗传小鼠模型。 在这里，我们建议使用 AML 细胞系、原代 AML 样本进行体外和体内临床前研究 以及两种 FLT3 突变 AML 小鼠模型，以评估靶向自分泌和旁分泌的功效 EGFL7 在 AML 中的作用。总体而言，该提案旨在定义 EGFL7 在 EGFL7 之间的串扰中的作用 BMM 和白血病细胞并生成临床前数据以支持抗 EGFL7 的临床开发 单克隆抗体与 FLT3 抑制剂联合治疗 FLT3 突变的 AML。