Structure-Function Investigation of Chemokine-GPCR Signaling in Tumor Progression and Metastasis

项目总结 上皮性卵巢癌(EOC)是女性癌症死亡的第五大原因。EoC有90% 如果及早发现存活率，但由于其非特异性症状，许多病例直到 转移瘤已经存在。在其晚期转移阶段，尚无有效的治疗方法 平等机会委员会。此外，EoC复发是常见的，并经常与对 可用的治疗方法。因此，迫切需要新的EOC疗法，特别是那些针对 转移。肿瘤细胞迁移到新部位的一种方式是通过趋化因子。趋化因子很小 在疾病和体内平衡过程中，指导细胞迁移或趋化的分泌蛋白质。 趋化因子通过与它们的同源细胞表面受体结合来触发细胞迁移，这些受体是 G蛋白偶联受体超家族。趋化因子与其受体的结合触发一种信号 级联反应，最终导致细胞骨架重组，趋化到趋化因子浓度较高的区域。 肿瘤细胞可以通过上调趋化因子和趋化因子受体的表达来劫持这一过程，从而 肿瘤细胞沿着趋化因子梯度向远处迁移。趋化因子受体XCR1具有 在许多癌症中表达增加，并与肿瘤细胞增殖和 迁移。在小鼠模型中，沉默XCR1被证明能显著减少卵巢癌的转移。 我们的实验室最近对XCL1，XCR1的趋化因子配体进行了深入的表征，导致 识别对受体结合和激活至关重要的配基残基。这项建议旨在 通过阐明XCR1中的重要残基来促进这一知识，XCR1是一种比其更有活力的药物靶点 并研究XCL1-XCR1轴在上皮性卵巢癌转移中的作用。 具体地说，该奖学金的目标是使用互补的生化和功能方法来 检验XCL1-XCR1界面上的特定分子间接触是EOC的关键驱动因素的假设 细胞迁移。奖学金研究将由两个具体目标组成。目标1将检验假设 XCR1‘S正构体结合口袋中的某些残基在XCR1-XCL1信号转导中起着至关重要的作用。目标2将测试 假设XCR1是由以前没有探索过XCR1表达的人EOC细胞株表达的，以及 变异的XCL1蛋白将在XCR1阳性的人EOC细胞中诱导独特的趋化特性，包括 在这个目标的第一部分中发现的那些。这项研究将在布赖恩·沃尔克曼实验室进行， 威斯康星医学院，一个高度协作和刺激的环境，配备了 基础设施和设备使这项提议取得成功。总而言之，理解基本的结构性 趋化因子配体-受体相互作用的特征将揭示推动肿瘤进展和 转移。利用结构和功能的互补关系将产生重要的洞察力 针对癌症进展和转移的更好和更特异的治疗方法的发展。

PROJECT SUMMARY Epithelial Ovarian Cancer (EOC) is the 5th leading cause of cancer death in women. EOC has a 90% survival rate if detected early, but due to its non-specific symptoms, many cases go undetected until metastases are already present. In its late metastatic stages, there are no effective treatments available for EOC. Furthermore, EOC recurrence is common, and is frequently associated with loss of sensitivity to available therapies. Thus, there is a dire need for novel EOC therapeutics, especially those that target metastasis. One way that tumor cells can migrate to new sites is via chemokines. Chemokines are small secreted proteins that direct the cell migration, or chemotaxis, in both disease and homeostatic processes. Chemokines trigger cell migration by binding to their cognate cell-surface receptors, which are members of the G-Protein Coupled Receptor superfamily. Binding of chemokines to their receptors triggers a signaling cascade, culminating in cytoskeletal reorganization and chemotaxis to areas of high chemokine concentration. Tumor cells can hijack this process by upregulating chemokine and chemokine receptor expression, allowing tumor cells to migrate to distant sites along chemokine gradients. The chemokine receptor XCR1 has increased expression in many cancers and has been associated with increased tumor cell proliferation and migration. Silencing of XCR1 in murine models has been shown to significantly decrease metastasis of EOC. Our lab recently performed in-depth characterization of XCL1, the chemokine ligand for XCR1, leading to the identification of ligand residues that are critical for receptor binding and activation. This proposal aims to advance this knowledge by elucidating important residues in XCR1, which is a more viable drug target than its ligand, and to study the functional role of the XCL1-XCR1 axis in the metastasis of epithelial ovarian cancer. Specifically, the goal of this fellowship is use complementary biochemical and functional approaches to test the hypothesis that specific intermolecular contacts at the XCL1-XCR1 interface are critical drivers of EOC cell migration. The fellowship research will consist of two specific aims. Aim 1 will test the hypothesis that certain residues in XCR1's orthosteric binding pocket are crucial for XCR1-XCL1 signaling. Aim 2 will test the hypothesis that XCR1 is expressed by human EOC cell lines not previously probed for XCR1 expression, and that variant XCL1 proteins will elicit unique chemotactic profiles in XCR1-positive human EOC cells including those discovered in the first part of this aim. The research will take place in the Brian Volkman lab at the Medical College of Wisconsin, a highly collaborative and stimulating environment that is well equipped with the infrastructure and equipment to make this proposal a success. In all, understanding the fundamental structural characteristics of chemokine ligand-receptor interactions will reveal mechanisms driving tumor progression and metastasis. Exploiting the complementary relationship of structure and function will yield vital insight towards the development of better and more specific therapeutics targeting cancer progression and metastasis.