Role of the Fractalkine Signaling in EOC

描述(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难题。目前使用的治疗方法并不是针对卵巢上皮性癌转移的特异性的，在保持患者病情缓解方面效果不佳。因此，以促转移途径为靶点可以提供更好的机会来提高存活率。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进展中发挥重要作用；2)已被证明是治疗其他疾病的有效靶点。趋化因子信号对癌细胞的迁移、增殖、黏附和侵袭是必不可少的，也就是成功发生转移所必需的特性。在这一应用中，我们将描述Fractalkine通路在卵巢癌转移发展中的关键作用，并确定其主要参与者趋化因子Fractalkine(CX3CL1)及其受体Fractalkine CX3CR1作为未来旨在预防和延缓转移转移的治疗的新靶点的潜在用途。我们的初步数据显示，人卵巢癌原发和转移标本中CX3CR1呈高度阳性，而非疾病对照组的正常卵巢表面上皮CX3CR1为阴性。此外，我们还发现EOC细胞可以CX3CR1依赖的方式向CX3CL1迁移。此外，在我们的初步实验中，在EOC细胞中增加CX3CR1的表达导致在异种移植的EOC小鼠模型中形成更多更大尺寸的肿瘤。趋化因子是很有希望的药物靶点。此外，趋化因子受体是G蛋白偶联受体，这是一类有效的药物靶标，覆盖了FDA批准的药物的约30%。此类药物已被证明在临床上有效，针对CX3CL1和CX3CR1的新药目前正在开发中。CX3CL1/CX3CR1是唯一合适的药物靶点，因为趋化因子与其受体之间的相互作用是非常特异的，而且与其他表现出高交叉反应的趋化因子/受体对不同，没有其他趋化因子配体激活CX3CR1。因此，针对CX3CR1或CX3CL1的药物可能只影响CX3CL1/CX3CR1轴。根据我们的初步数据和已发表的文献，我们的假设是CX3CL1/CX3CR1轴是将转移的EOC细胞归巢到腹膜并通过支持细胞黏附和迁移促进转移扩散所必需的。为了检验这一假设，我们提出了两个目标。在目标1中，我们将利用细胞培养模型和之前美国卵巢癌转移特异性培养条件来确定CX3CL1/CX3CR1在与腹膜间皮细胞和基础细胞外基质黏附方面的需求。粘连是腹膜转移性定植的主要起始步骤之一。在目标2中，我们将利用异种移植小鼠模型来表征CX3CL1/CX3CR1在体内发生EOC转移过程中的需求。 公共卫生相关性：卵巢上皮癌是妇科最致命的恶性肿瘤，主要由转移引起，是公共卫生中一个尚未解决的问题。在这个方案中，我们将描述卵巢癌进展中对趋化因子信号的需求，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主要作用，以及2)趋化因子及其受体是在临床上被证明在治疗其他疾病中起作用的有效药物靶点。

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.