Molecular, functional and micro-morphological imaging of bone metastases in vivo

在骨转移过程中，骨微环境的复杂性和多种细胞类型相互作用的复杂性要求开发适合于体内这些过程的多模式分子、功能和微形态成像的技术。我们将测试是否可以使用成骨细胞、破骨细胞和肿瘤细胞相互作用的分子标记来在微观结构水平上对这些细胞在骨转移过程中进行纵向监测。放置在成骨细胞组织特异性启动子α1(I)-胶原控制下的光学报告基因将允许标记免疫缺陷小鼠品系中的成骨细胞谱系细胞。基于反映成骨细胞诱导的基质结合、破骨细胞数量(αvβ3整合素)和功能(组织蛋白K表达)的荧光标记物的成像方法将被开发来研究肿瘤与骨的相互作用，例如Dickkopf-1。结合荧光分子断层扫描(FMT)和微型计算机断层扫描(Micro-CT)的多模式成像将被优化用于定量纵向评估。我们的工作将使可量化的FMT/Micro-CT标记物和方法得到验证，这些标记物和方法具有成像合作伙伴项目中描述的肿瘤-骨相互作用特异性靶点的潜力。这种方法将增强非侵入性监测转移过程的能力，也是对治疗的反应。

The complexity of the bone microenvironment and the multitude of cell types interacting with each other during skeletal metastasis necessitate the development of technologies suited for multimodal molecular, functional and micro-morphological imaging of these processes in vivo. We will test the hypothesis whether molecular markers specific for osteoblasts, osteoclasts and tumor cell interaction can be employed to allow for longitudinal monitoring of these cells during skeletal metastasis at the microstructural level. An optical reporter gene placed under the control of the osteoblast tissue-specific promoter, α1(I)-collagen, will allow to label cells of the osteoblastic lineage in an immunodeficient mouse strain. Imaging methods based on fluorescent markers reflecting osteoblast induced matrix apposition, osteoclast number (αvβ3 integrin) and function (cathepsin K expression) will be developed to study tumor-bone interaction, e.g. with regard to Dickkopf-1. Multi-modality imaging combining fluorescent molecular tomography (FMT) and micro-computed tomography (micro-CT) will be optimized for quantitative longitudinal evaluation. Our work will result in validation of a robust basic armamentarium of quantifiable FMT/micro-CT markers and methods with potential to image tumor-bone interaction-specific targets which are characterized in partner projects. Such methods will augment the ability to non-invasively monitor metastatic processes also in response to treatment.