In vivo detection of involvement of endogenous BM progenitor cells in glioma

描述（由申请人提供）：由于胶质母细胞瘤（GBM）的高血管性和相关的血管生成活跃，研究人员添加了抗血管生成治疗作为辅助治疗，以使血管正常化和控制异常血管生成。抗血管生成治疗干扰肿瘤血管系统，导致明显缺氧。在GBM中，缺氧导致缺氧诱导因子1- α (HIF-1)上调。HIF-1上调SDF-1，而SDF-1反过来可能募集各种促血管生成的骨髓源性细胞。任何诱导更多EPCs的治疗都可能促进新生血管和促生长，这是抗血管生成治疗的矛盾效应。因此，我们假设使用VEGFR抑制剂进行抗血管生成治疗会启动促血管生成因子的释放，导致内皮祖细胞（EPCs）或骨髓祖细胞（BMPCs）（不同类型的干细胞）的迁移和积累，并增强难治性肿瘤的血管生成。本研究的目的是通过建立嵌合小鼠模型，并应用新颖的无创、最先进的MRI和光学成像方法来监测肿瘤进展和相关外源性和内源性EPCs的迁移，阐明难治性胶质瘤的新生血管形成机制。我们将分三个阶段进行研究：(1)建立嵌合小鼠模型，在人泛素C启动子控制下，用从表达GFP蛋白的转基因小鼠（C57BL/6-Tg(UBC-GFP)30Scha/J）骨髓中收集的骨髓细胞代替亚致死照射的胸腺小鼠骨髓。这些嵌合小鼠将被用于产生原位人类胶质瘤。(2)我们将通过MRI确定肿瘤血管通透性、增强模式、分布体积和扩散参数的变化，以及单独或联合使用vetanalib或AMD3100（或较新的强效CXCR4抑制剂）治疗后肿瘤和周围组织中不同血管生成因子及其相关受体的变化；(3)我们将分别通过光学成像和细胞MRI来确定内源性BMPCs和外源性EPCs在vetanalib或AMD3100（或一种较新的有效的CXCR4抑制剂）抗血管生成治疗期间的参与情况，这些发现将与血管生成因子和受体的表达相关。内源性BMPCs和外源性EPCs在肿瘤新生血管形成中的作用也将被比较和关联。预计干细胞在抗血管生成治疗中具有重要作用。在不同的治疗方案下，内源性或给药干细胞积累的差异将证明我们的假设，即干细胞在抗血管生成治疗中发挥作用。的相关性

DESCRIPTION (provided by applicant): Because of hypervascular nature of glioblastoma (GBM) and associated active angiogenesis, investigators have added anti-angiogenic treatment as an adjuvant to normalize blood vessels and control abnormal angiogenesis. Antiangiogenic therapy disturbs tumor vasculature, leading to marked hypoxia. In GBM, hypoxia leads to up-regulation of hypoxia inducible factor 1-alpha (HIF-1). HIF-1 up-regulates SDF-1, which in turn may recruit various pro-angiogenic bone marrow-derived cells. Any therapy that invites more EPCs might promote neovascularization and pro growth, a paradoxical effect of anti-angiogenic therapy. Therefore, we hypothesize that anti-angiogenic treatment using VEGFR inhibitors would initiate the release of pro-angiogenic factors, causing migration and accumulation of endothelial progenitor cells (EPCs) or bone marrow progenitor cells (BMPCs) (different types of stem cells), and enhanced angiogenesis in refractory tumors. The goal of this study is to elucidate neovascularization mechanisms in refractory glioma by making chimeric mouse model and applying novel non-invasive, state of the art MRI and optical imaging approach to monitor tumor progression and associated exogenous and endogenous EPCs' migration. We will conduct the research in three phases: (1) we will establish chimeric mouse model where bone marrow of sub-lethally irradiated athymic mouse will be replaced by bone marrow cells collected from bone marrow of transgenic mouse (C57BL/6-Tg(UBC-GFP)30Scha/J) that express GFP protein under the control of human ubiquitin C promoter. These chimeric mice will be used to generate orthotopic human glioma. (2) we'll determine the changes in tumor vascular permeability, enhancement patterns, distribution volume, and diffusion parameters by MRI, and changes in different angiogenic factors and their associated receptors in the tumor and surrounding tissues following the treatment with vetanalib or AMD3100 (or a newer potent CXCR4 inhibitor), separately or in combination; (3) we'll determine the involvement of endogenous BMPCs and exogenous EPCs by optical imaging and cellular MRI, respectively, during antiangiogenic treatments with vetanalib or AMD3100 (or a newer potent CXCR4 inhibitor), separately or in combination, and the findings will be correlated with the expression o angiogenic factors and receptors. Involvement of endogenous BMPCs and exogenous EPCs in tumor neovascularization will also be compared and correlated. It is anticipated that there is a strong role of stem cells during anti-angiogenic therapy. Differences in accumulation of the endogenous or administered stem cells following different treatment schedule will prove our hypothesis that there is a role for stem cells during anti-angiogenic treatment. Correlation of the accumulated administered stem cells with MRI findings and the expression of different angiogenic receptors will help clinicians to modify treatment strategy when anti-angiogenic therapy is considered.