Exploration of the role of neural-type receptors and the ECM proteins SPARC and Tenascin C in the bone marrow HSC-niche unit

探索神经型受体以及 ECM 蛋白 SPARC 和 Tenascin C 在骨髓 HSC 生态位单元中的作用

• 批准号: 246083836
• 负责人: Professor Dr. Daniel Nowak
• 金额: --
• 依托单位: III. Medizinische Klinik: Hämatologie und Internistische Onkologie
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2013
• 资助国家: 德国
• 起止时间: 2012-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/246083836?language=en
• 关键词: Exploration; role; neural; type; receptors

Myelodysplastic syndromes (MDS) are clonal hematologic disorders characterized by ineffective hematopoiesis, peripheral cytopenias and dysplastic bone marrow cells, with increased risk of evolution to acute myeloid leukemia (AML). MDS is not only a disease of the hematopoietic cell compartment but also alterations in the bone marrow niche influence the development of myeloid neoplasms. Based on this hypothesis, in previous joint collaborative work we have established a robust xenograft model of human MDS based on the co-transplantation of patient derived CD34+ hematopoietic stem cells (HSCs) and bone marrow (BM) derived stromal cells (MSCs). Our work revealed an instructive remodeling of the microenvironment induced by MDS HSCs to preferentially support their own growth. One of the key factors significantly overexpressed in MDS derived MSCs was the extracellular matrix protein secreted protein acidic and rich in cysteine (SPARC). SPARC has been implicated as a central factor in mediating tumor cell interaction with surrounding stroma and metastasis of a variety of solid tumors. In hematologic malignancies, we could show that loss of SPARC in the bone marrow stroma compartment protects hematopoietic cells from chemotherapy toxicity. In the current proposal we aim to use our unique MDS xenograft model to elucidate the molecular mechanisms of SPARC in order to possibly identify new therapeutic strategies that are targeted against the aberrant stroma compartment in myeloid neoplasms. To accomplish this we have crossed previous murine SPARC knockout strains with the NSG model in order to generate NSG SPARC knockout mice. Primary MDS derived and healthy bone marrow samples will be xenotransplanted into this model to study the biologic effect of absence or presence SPARC in the bone marrow niche. As a readout beside engraftment rates, the clonal bone marrow composition of the MDS xenografts will be analyzed via quantitative mutation and immunophenotypic analyses of primary patient samples and MDS xenografts. To analyze the instructive crosstalk between the hematopoietic compartment and the bone marrow stroma, we will perform whole transcriptome RNA sequencing in primary sorted stroma cell fractions, including subfractions such as endothelial cells, osteoblasts and mesenchymal stem cells after exposure to the MDS HSCs in vivo. Beyond this, we will use our model as a pre-clinical platform to test whether by manipulation of the bone marrow niche with either addition of exogenous SPARC or its inhibition, positive effects on MDS biology, clonal composition or improvement of functional blood components can be achieved. The application of pharmacologic substances that have been implicated in the biology of SPARC in the context of other tumor entities such as Bortezomib and nab-Paclitaxel will be evaluated as potential therapies targeting the bone marrow stroma of MDS.

骨髓增生异常综合征（MDS）是一种克隆性血液系统疾病，其特征是造血功能低下、外周血细胞减少和骨髓细胞发育异常，并伴有向急性髓性白血病（AML）演变的风险增加。MDS不仅是一种造血细胞区室疾病，而且骨髓生态位的改变也影响骨髓肿瘤的发展。基于这一假设，在先前的联合合作工作中，我们已经建立了基于患者来源的CD 34+造血干细胞（HSC）和骨髓（BM）来源的基质细胞（MSC）的共移植的人MDS的稳健异种移植模型。我们的工作揭示了MDS HSC诱导的微环境的有益重塑，以优先支持其自身的生长。MDS来源的MSC中显著过表达的关键因素之一是细胞外基质蛋白分泌的酸性且富含半胱氨酸的蛋白质（Cys）。在介导肿瘤细胞与周围基质的相互作用和多种实体瘤的转移中，β-淀粉样蛋白被认为是一个中心因子。在恶性血液病中，我们发现骨髓间质区室中的CD 4+的丢失保护造血细胞免受化疗毒性的影响。在目前的提案中，我们的目标是使用我们独特的MDS异种移植模型来阐明MDS的分子机制，以可能确定针对骨髓肿瘤中异常基质区室的新的治疗策略。为了实现这一点，我们已经将先前的鼠NSG敲除品系与NSG模型杂交，以产生NSG NSG敲除小鼠。将原发性MDS来源的和健康的骨髓样品异种移植到该模型中，以研究骨髓生态位中不存在或存在骨髓瘤的生物学效应。作为植入率以外的读数，将通过原始患者样本和MDS异种移植物的定量突变和免疫表型分析来分析MDS异种移植物的克隆骨髓组成。为了分析造血区室和骨髓基质之间的指导性串扰，我们将在体内暴露于MDS HSC后，在初级分选的基质细胞组分中进行全转录组RNA测序，包括亚组分如内皮细胞、成骨细胞和间充质干细胞。除此之外，我们将使用我们的模型作为临床前平台，以测试是否通过添加外源性β-内酰胺酶或其抑制剂来操纵骨髓生态位，可以实现对MDS生物学、克隆组成或功能性血液成分改善的积极作用。在其他肿瘤实体（如硼替佐米和nab-紫杉醇）的背景下，与MDS生物学相关的药理学物质的应用将作为靶向MDS骨髓基质的潜在疗法进行评价。