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) 是一种克隆性血液疾病，其特征是无效造血、外周血细胞减少和骨髓细胞发育不良，且演变为急性髓系白血病 (AML) 的风险增加。 MDS不仅是造血细胞区室的疾病，而且骨髓生态位的改变也会影响骨髓肿瘤的发展。基于这一假设，在之前的联合协作工作中，我们基于患者来源的 CD34+ 造血干细胞 (HSC) 和骨髓 (BM) 来源的基质细胞 (MSC) 的共同移植，建立了强大的人类 MDS 异种移植模型。我们的工作揭示了 MDS HSC 诱导的微环境重塑，以优先支持其自身生长。 MDS 衍生的 MSC 中显着过度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 (SPARC)。 SPARC 被认为是介导肿瘤细胞与周围基质相互作用以及多种实体瘤转移的核心因素。在血液恶性肿瘤中，我们可以证明骨髓基质室中 SPARC 的缺失可以保护造血细胞免受化疗毒性。在当前的提案中，我们的目标是使用我们独特的 MDS 异种移植模型来阐明 SPARC 的分子机制，以便可能确定针对骨髓肿瘤中异常基质区室的新治疗策略。为了实现这一目标，我们将之前的 SPARC 敲除小鼠品系与 NSG 模型进行杂交，以产生 NSG SPARC 敲除小鼠。原代 MDS 衍生的健康骨髓样本将被异种移植到该模型中，以研究骨髓生态位中 SPARC 缺失或存在的生物学效应。作为植入率之外的读数，MDS 异种移植物的克隆骨髓组成将通过对主要患者样本和 MDS 异种移植物进行定量突变和免疫表型分析来分析。为了分析造血室和骨髓基质之间的指导性串扰，我们将对初级分选的基质细胞组分（包括体内暴露于 MDS HSC 后的内皮细胞、成骨细胞和间充质干细胞等亚组分）进行全转录组 RNA 测序。除此之外，我们将使用我们的模型作为临床前平台来测试通过添加外源性 SPARC 或其抑制来操纵骨髓生态位是否可以对 MDS 生物学、克隆组成或功能性血液成分的改善产生积极影响。实现了。与 SPARC 生物学有关的药理学物质在其他肿瘤实体（如硼替佐米和白蛋白结合型紫杉醇）中的应用将被评估为针对 MDS 骨髓基质的潜在疗法。