Molecular Imaging of Chemokine Receptor Signaling

摘要 趋化因子受体信号是原发肿瘤生长和转移的关键决定因素 许多常见癌症的器官特异性转移。特别是，我们的实验室和 其他研究表明，趋化因子受体CXCR4和CXCR7在 乳腺癌和肺癌中的恶性细胞。CXCR4和CXCR7信号转导显著 增加原发肿瘤负担，提高转移性肿瘤的生存和增殖 癌症细胞，所有这些都对患者的生活质量和生存产生不利影响。 肿瘤微环境中的趋化因子受体信号是由基质细胞启动的 分泌趋化因子配体的物质。这些配体与肿瘤细胞上的同源受体结合， 从而激活控制肿瘤进展和转移的下游效应器。 了解趋化因子受体CXCR4和CXCR7的整合功能 对于解剖原发癌和转移性癌症的分子调控是必不可少的 有效靶向这些受体以改善癌症治疗。我们假设 可以开发分子成像报告器来检测和量化多个步骤 CXCR4和CXCR7在基于细胞的分析和乳腺癌小鼠模型中的信号转导。 这些成像记者建立在我们在蛋白质-蛋白质相互作用成像方面的专业知识 在信号通路中。在目标1中，我们将开发一种荧光素酶互补报告 趋化因子配体与乳腺CXCR4、CXCR7细胞外结合分析 癌细胞。在目标2中，我们将构建一个成像报告系统来量化 细胞表面趋化因子受体复合体及其在细胞周期中的变化 发信号。最后，Aim 3将开发一种细胞内激活的成像报告 CXCR4和CXCR7基于支架蛋白-arrestin的募集。这 研究将建立新的成像技术来研究细胞的综合功能 CXCR4和CXCR7在乳腺癌中的表达及靶向治疗 完整细胞和活体小鼠体内的趋化因子受体。除了目前的研究，每一项 在这些记者技术中，有望成为研究 趋化因子和趋化因子受体的整个家族，扩大了它们的应用 除癌症外，许多疾病的成像技术。这项研究的意义在于它将开发新的成像技术 乳腺和其他多种组织中的细胞间和细胞内信号网络 常见的癌症。这些成像记者将促进我们对细胞信号的了解 在癌症发生和发展为转移疾病的临床前模型中。vbl.使用 这些成像技术还将极大地提高我们测试和验证新的 治疗药物，我们预计这将导致改善患者的治疗 癌症。

Abstract Chemokine receptor signaling is a critical determinant of primary tumor growth and organ-specific metastases in many common cancers. In particular, our laboratory and others have shown that chemokine receptors CXCR4 and CXCR7 are upregulated on malignant cells in breast and lung cancer. CXCR4 and CXCR7 signaling significantly increases primary tumor burden and enhances survival and proliferation of metastatic cancer cells, all of which adversely affect quality of life and survival for patients. Chemokine receptor signaling in the tumor microenvironment is initiated by stromal cells that secrete chemokine ligands. These ligands bind to cognate receptors on tumor cells, thereby activating downstream effectors that control tumor progression and metastasis. Understanding integrated functions of chemokine receptors CXCR4 and CXCR7 is essential for dissecting molecular regulation of primary and metastatic cancer and effectively targeting these receptors to improve cancer therapy. We hypothesize that molecular imaging reporters can be developed to detect and quantify multiple steps in CXCR4 and CXCR7 signaling in cell-based assays and mouse models of breast cancer. These imaging reporters build upon our expertise in imaging protein-protein interactions in signaling pathways. In aim 1, we will develop a luciferase complementation reporter to analyze extracellular binding of chemokine ligands to CXCR4 and CXCR7 on breast cancer cells. In aim 2, we will construct an imaging reporter system to quantify chemokine receptor complexes on cells and changes in these complexes during signaling. Finally, aim 3 will develop an imaging reporter for intracellular activation of CXCR4 and CXCR7 based on recruitment of the scaffolding protein ¿-arrestin. This research will establish new imaging technologies to investigate integrated functions of CXCR4 and CXCR7 in breast cancer and establish therapeutic targeting of these chemokine receptors in intact cells and living mice. Beyond the current research, each of these reporter technologies is expected to serve as a general method to study the entire family of chemokines and chemokine receptors, extending applications of these imaging techniques to many diseases besides cancer. The significance of this research is that it will develop new techniques to image intercellular and intracellular signaling networks in breast and a wide range of other common cancers. These imaging reporters will advance our knowledge of cell signaling in pre-clinical models of cancer initiation and progression to metastatic disease. Using these imaging technologies also will greatly improve our ability to test and validate new therapeutic agents, which we anticipate will lead to improved treatments for patients with cancer.