Influence of the skeletal remodeling status on tumor cell dissemination and metastatic outgrowth

骨骼重塑状态对肿瘤细胞播散和转移生长的影响

• 批准号: 401122336
• 负责人: Professor Dr. Michael Amling
• 金额: --
• 依托单位: Institut für Osteologie und Biomechanik (IOBM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2018
• 资助国家: 德国
• 起止时间: 2017-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/401122336?language=en
• 关键词: Influence; skeletal; remodeling; status; tumor

The bone matrix is continuously remodeled through the balanced activities of two substantially different cell types, bone-forming osteoblasts and bone-resorbing osteoclasts. Our Institute has a long expertise in bone-specific cellular and molecular characterization of genetically modified mouse models, and we have identified several key mechanisms controlling skeletal remodeling in the last years. For the present proposal we will continue our ongoing collaboration with the group of Prof. Klaus Pantel to address the question, if and how an impaired bone remodeling status affects tumor cell dissemination and metastatic outgrowth in vivo.For that purpose we will inject human and murine breast cancer cells into mice to study skeletal metastasis formation as well as changes in the bone microenvironment by Luciferase reporter gene assays, µCT, undecalcified histology and bone-specific histomorphometry. Most importantly, and in contrast to the majority of previously published studies, we do not aim at modifying the seed (i.e. the tumor cells), but the soil (i.e. the recipient mouse). To achieve our goals we have backcrossed different mouse models into genetic backgrounds (BALB/c and NSG) allowing xenotransplantation or syngeneic transplantation of cancer cells. While three of the models (Calca-/-, Calcr-/- and Notch2+/HCS) display specific disturbances of the coupling mechanisms required to synchronize bone formation and bone resoprtion, the other four models (Lrp5+/HBM, Col1a1-Sost, Col1a1-Krm2 and Col1a1-tTA;pTet-Wnt1) display selective changes in osteoblast activity. Since all these genetically modified mouse models have been previously analyzed to define not only their bone remodeling status, but also the molecular causes of the observed phenotypes, we expect that our results will clearly identify, which bone remodeling cell type is primarily involved in the suggested detrimental crosstalk between bone and tumor cells.In addition to this in vivo approach we will perform ex vivo co-culture experiments with breast cancer and bone remodeling cells to define specific molecular interactions. Although our project principally follows an unbiased approach, there are some hypotheses that will be addressed. For instance, since we have previously found that calcitonin (CT) controls bone formation by inhibiting the release of sphingosine 1-phosphate (S1P) from osteoclasts, we will analyze if CT, S1P and/or antagonists of specific S1P receptors will influence proliferation and/or migration of cancer cells, cultured alone or together with bone remodeling cell types.

骨基质是通过两种完全不同的细胞类型，成骨细胞和骨吸收破骨细胞的平衡活动而不断重塑的。我们的研究所在遗传修饰小鼠模型的骨特异性细胞和分子表征方面具有长期的专业知识，并且在过去几年中我们已经确定了控制骨骼重塑的几个关键机制。对于目前的提案，我们将继续与Klaus Pantel教授小组合作，解决这个问题，受损的骨重塑状态是否以及如何影响肿瘤细胞在体内的传播和转移性生长。为此，我们将把人类和小鼠乳腺癌细胞注射到小鼠体内，通过荧光素酶报告基因检测、微CT、未钙化组织学和骨特异性组织形态学分析来研究骨骼转移的形成以及骨微环境的变化。最重要的是，与之前发表的大多数研究相反，我们的目标不是修改种子（即肿瘤细胞），而是修改土壤（即受体小鼠）。为了实现我们的目标，我们将不同的小鼠模型回交到遗传背景（BALB/c和NSG）中，允许癌细胞异种移植或同基因移植。其中三种模型（Calca-/-， Calcr-/-和Notch2+/HCS）显示同步骨形成和骨再吸收所需的耦合机制的特异性干扰，其他四种模型（Lrp5+/HBM, Col1a1-Sost， Col1a1-Krm2和Col1a1-tTA；pTet-Wnt1）显示成骨细胞活性的选择性变化。由于所有这些转基因小鼠模型之前都被分析过，不仅确定了它们的骨重塑状态，而且还确定了观察到的表型的分子原因，我们希望我们的结果能够清楚地确定，哪种骨重塑细胞类型主要参与了骨和肿瘤细胞之间的有害串扰。除了这种体内方法，我们还将进行乳腺癌和骨重塑细胞的体外共培养实验，以确定特定的分子相互作用。虽然我们的项目主要遵循无偏见的方法，但仍有一些假设需要解决。例如，由于我们之前发现降钙素（CT）通过抑制破骨细胞释放鞘氨醇1-磷酸（S1P）来控制骨形成，我们将分析CT、S1P和/或特定S1P受体的拮抗剂是否会影响单独培养或与骨重塑细胞类型一起培养的癌细胞的增殖和/或迁移。