Role of the Fractalkine Signaling in EOC

描述（由申请人提供）：上皮性卵巢癌（EOC）是妇科恶性肿瘤死亡的主要原因。腹膜转移是卵巢癌治疗中尚未解决的临床问题。目前使用的治疗方法并不特异于EOC转移，并且在保持患者缓解方面效率低下。因此，靶向促转移途径可以提供改善的机会来增加存活率。在我们寻找新靶点的方法中，我们在满足以下标准的途径中进行了搜索：1）在EOC进展中起主要作用; 2）已被证明是治疗其他疾病的有效靶点。趋化因子信号传导对于癌细胞迁移、增殖、粘附和侵袭是必需的，即，这些特性是成功发展转移所必需的。在本申请中，我们将表征fractalkine途径对EOC转移的发展至关重要，并确定其主要参与者趋化因子fractalkine（CX 3CL 1）及其受体fractalkine CX 3CR 1作为未来治疗的新靶点的潜在用途，旨在预防和阻滞转移性扩散。我们的初步数据显示，原发性和转移性卵巢上皮癌标本CX 3CR 1高度阳性，而正常对照组卵巢表面上皮CX 3CR 1阴性。此外，我们发现EOC细胞可以CX 3CR 1依赖的方式迁移到CX 3CL 1。此外，在我们的初步实验中，EOC细胞中CX 3CR 1表达的增加导致在异种移植物EOC小鼠模型中形成更多更大尺寸的肿瘤。趋化因子是很有前途的药物靶点。此外，趋化因子受体是G蛋白偶联受体，这类蛋白质是有效的药物靶标，覆盖估计30%的FDA批准的药物。此类药物已被证明在临床上有效，目前正在开发针对CX 3CL 1和CX 3CR 1的新药。CX 3CL 1/CX 3CR 1是一个独特的合适的药物靶点，因为趋化因子与其受体之间的相互作用是非常特异性的，并且与显示高交叉反应性的其他趋化因子/受体对相比，没有其他趋化因子配体激活CX 3CR 1。因此，针对CX 3CR 1或CX 3CL 1的药物可能仅影响CX 3CL 1/CX 3CR 1轴。基于我们的初步数据和已发表的文献，我们的假设是CX 3CL 1/CX 3CR 1轴是将转移性EOC细胞归巢到腹膜并通过支持细胞粘附和迁移促进转移性扩散所必需的。为了验证这一假设，我们提出了两个目标。在目标1中，我们将使用细胞培养模型和先前由我们开发的EOC转移特异性培养条件来确定CX 3CL 1/CX 3CR 1粘附于腹膜间皮细胞和基础细胞外基质的需求。粘连是腹膜转移性定植的主要起始步骤之一。在目标2中，我们将使用异种移植小鼠模型来表征在体内EOC转移的发展中对CX 3CL 1/CX 3CR 1的需求。 公共卫生相关性：上皮性卵巢癌是最致命的妇科恶性肿瘤，主要是由于转移，是一个悬而未决的问题，在公共卫生。在本提案中，我们将描述卵巢癌进展中对趋化因子信号传导的需求，因为1）根据我们的初步数据，它可能在卵巢癌转移级联的所有阶段中发挥重要作用，2）趋化因子及其受体是有效的药物靶点，已被证明在临床治疗其他疾病中有效。

DESCRIPTION (provided by applicant): Epithelial ovarian carcinoma (EOC) is a leading cause of death from gynecologic malignancies. Peritoneal metastasis is an unsolved clinical problem in treatment of EOC. Currently used therapeutic approaches are not specific to EOC metastasis and are inefficient at keeping patients in remission. Thus, targeting the pro-metastatic pathways could provide improved opportunities to increase survival. In our approach to find new targets we searched among pathways that satisfy the following criteria: 1) play a major role in EOC progression; 2) have proven to be effective targets for treatments of other diseases. Chemokine signaling is essential for cancer cell migration, proliferation, adhesion, and invasion, i.e., properties that are necessary for a successful development of metastasis. In this application we will characterize fractalkine pathway as crucial for the development of metastasis in EOC and determine potential usefulness of its main players, chemokine fractalkine (CX3CL1) and its receptor, fractalkine CX3CR1, as novel targets for future therapies aimed at prevention and retardation of metastatic spread. Our preliminary data show that primary and metastatic specimens of human EOC are highly positive for CX3CR1, while normal ovarian surface epithelium in non-diseased control subjects is CX3CR1-negative. Moreover, we show that EOC cells can migrate in CX3CR1-dependent manner to CX3CL1. Furthermore, in our pilot experiments increase of CX3CR1 expression in EOC cells led to formation of more tumors of larger size in a xenograft EOC mouse model. Chemokines are promising drug targets. Moreover, chemokine receptors are the G protein coupled receptors, a class of proteins that are effective drug targets covering an estimated 30% of FDA approved drugs. Such drugs have been proven to work in the clinic, and new drugs against CX3CL1 and CX3CR1 are currently under development. CX3CL1/CX3CR1 is a uniquely suitable drug target because the interaction between the chemokine and its receptor is very specific, and there are no other chemokine ligands activating CX3CR1, in contrast to other chemokine/receptor pairs that display high cross-reactivity. Thus, drugs directed at either CX3CR1 or CX3CL1 will likely to affect only the CX3CL1/CX3CR1 axis. Based on our preliminary data and published literature our hypothesis is that CX3CL1/CX3CR1 axis is required for homing metastatic EOC cells to the peritoneum and facilitation of metastatic spread by supporting cell adhesion and migration. To test this hypothesis we propose two aims. In Aim 1 we will determine the requirement of CX3CL1/CX3CR1 in adhesion to peritoneal mesothelial cells and underlying extracellular matrix using cell culture models and previously developed by us EOC metastasis-specific culture conditions. Adhesion is one of the main initial steps of the metastatic colonization of the peritoneum. In Aim 2 we will characterize the requirement for CX3CL1/CX3CR1 in development of EOC metastasis in vivo using a xenograft mouse model. PUBLIC HEALTH RELEVANCE: Epithelial ovarian carcinoma is the deadliest gynecologic malignancy mainly due to metastasis and is an unsolved problem in public health. In this proposal we will characterize the requirement for chemokine signaling in progression of ovarian carcinoma, because 1) according to our preliminary data it could play a major role in all stages of the ovarian carcinoma metastatic cascade, and 2) chemokines and their receptors are effective drug targets proven to work in the clinic in treatments of other diseases.