Developing the coral implant model of bone metastasis

描述（由申请人提供）： 骨转移是晚期乳腺癌患者的一个重要临床问题。用于治疗和控制骨转移的靶向疗法的开发受到临床前模型的缺乏的阻碍，所述临床前模型将允许鉴定肿瘤细胞在骨微环境中被吸引和茁壮成长的分子机制。本提案的目的是开发一种新的动物模型，使用体内产生的“活化”骨基质研究转移性骨疾病的外渗和进展过程。这些研究代表了从细胞和分子角度具有转移专业知识的癌症生物学家与具有骨骼发生新组织工程模型专业知识的整形外科医生之间的合作。通过将羟基磷灰石取代的海洋珊瑚支架与血管链或蒂连接，在体内生成骨。移植物中充满了循环的骨祖细胞，5周内可形成骨类骨质。我们建议使用这种“充满活力”的骨来评估小鼠肿瘤细胞注射到椎弓根后的归巢和进展。肿瘤细胞将用荧光素酶基因标记，以允许使用生物发光成像技术随时间进行可视化和监测。这种方法提供了几个优势，现有的方法，包括有限的肿瘤细胞的传播，转移性细胞负荷的定量评估，并能够操纵骨微环境的各个组成部分。在原理实验的证明中，我们将使用这种方法来解决以下假设：由常驻骨细胞产生的基质金属蛋白酶MMP-2和MMP-9有助于恶性乳腺细胞在骨微环境中定植和生长的能力。这些研究将为进一步的研究奠定基础，以确定治疗和控制乳腺癌骨转移的新靶点。

DESCRIPTION (provided by applicant): Metastasis to the bone represents a significant clinical problem for patients with advanced stage breast cancer. The development of targeted therapies for the treatment and control of bone metastasis is hindered by the paucity of preclinical models that would allow the identification of the molecular mechanisms by which tumor cells are attracted and thrive in the bone microenvironment. The goal of this proposal is to develop a novel animal model to study the processes of extravasation and progression of metastatic bone disease using an in vivo generated 'vitalized' bone matrix. These studies represent a collaboration between cancer biologists with expertise in metastasis from a cellular and molecular perspective, and orthopedic surgeons with expertise in a novel tissue engineered model of skeletogenesis. Bone is generated in vivo by ligating a hydroxyapatite-substituted marine coral scaffold to a vascular leash or pedicle. The graft becomes populated with circulating bone progenitor cells, and bone osteoid can develop within 5 weeks. We propose to use this 'vitalized' bone to assess homing and progression of murine tumor cells following injection into the pedicle. The tumor cells will be tagged with the luciferase gene to allow visualization and monitoring with time using bioluminescent imaging techniques. This approach provides several advantages over existing methodology, including the limited dissemination of the tumor cells, the quantitative assessment of metastatic cell burden, and the ability to manipulate individual components of the bone microenvironment. In proof of principle experiments, we will use this methodology to address the hypothesis that production of the matrix metalloproteinases MMP-2 and MMP-9 by resident bone cells contributes to the ability of malignant breast cells to colonize and grow in the bone microenvironment. These studies will lay the foundation for further studies to identify novel targets for the treatment and control of breast-to-bone metastasis.