ANNEXIN II & PLASMIN MEDIATED HIGH GRADE GLIOMA INVASION

描述（申请人描述）： 恶性原发性脑肿瘤， 尤其是神经胶质瘤，其特征在于倾向于侵入周围组织， 大脑结构导致局部复发率高， 临床结果。 入侵过程是一连串复杂的事件。 虽然可能涉及多种机制，但似乎局灶性 细胞外基质（ECM）重塑需要蛋白水解活性， 可怕的入侵。 纤溶酶原-纤溶酶系统直接或通过 激活基质金属蛋白酶（MMPs）已被牵连在 ECM的蛋白水解重塑。 Annexin II（Ann II）是一种新发现的 内皮细胞表面蛋白是纤溶酶原（PLG）的共受体， 其激活剂为组织型纤溶酶原激活剂（t-PA）。 安II增加了 纤溶酶生成的催化效率超过基线60倍， 纯化蛋白系统。 我们使用了C6大鼠胶质瘤细胞，一种定义明确的 体外人高级别胶质瘤模型，以研究Ann的潜在作用 II型纤溶酶介导的侵袭。 初步的体外数据表明，C6 细胞大量表达膜联蛋白II（Ann II），增强纤溶酶的产生， 功能研究和介导的t-PA依赖性迁移的C6细胞通过 胶原和层粘连蛋白基质。 此外，高品位的侵入边缘 人神经胶质瘤在肿瘤细胞中显示Ann II强阳性染色。 根据这些初步数据，本项目将检验以下假设： Ann II在纤溶酶介导的高级别胶质瘤侵袭中起作用。 的 研究将集中在使用侵入和 基质降解试验，放射性标记结合试验，特异性功能性 测定和底物酶谱法。 此外，该假设将在一个 Fischer大鼠立体定向注射C6/lac Z细胞的体内系统 大脑产生肿瘤并用抗Ann II抗体抑制侵袭 和反义Ann II构建体。 人类脑肿瘤切片将被研究 免疫组化法检测Ann II、t-PA表达和纤溶酶活性。 通过 了解入侵的机制，也许可以设计新的 专门针对限制Ann II的脑肿瘤治疗方法- 介导的入侵。 这些研究也可能产生深远的影响 用于诊断和治疗其他局部侵袭性和转移性 肿瘤在各种各样的设置。 的 本申请的首席研究员是一个委员会认证的 儿科医生， 谁 期间 的 过程 的 培训 在 儿科 血液学/肿瘤学在血管生物学实验室工作了2年， 在凯瑟琳博士的指导下哈贾 计划将继续 在康奈尔大学威尔医学院的指导下。 她的实验室 是血栓形成研究专业中心和计划项目的一部分 在血管生物学，并配备了良好的进行调查。 除了每周的实验室会议，讨论个别项目，每周的研究 研讨会和期刊俱乐部提供了一个机会，以满足其他 医学院的研究人员和接触新思想。 Hajjar博士是 在需要时，也可以参加每周的个人会议。 这是 环境将为发展中国家提供良好的培训 医生兼研究员

DESCRIPTION (Applicant's Description): Malignant primary brain tumors, especially gliomas, are characterized by a propensity to invade surrounding brain structures resulting in a high rate of local recurrence and a dismal clinical outcome. The invasion process is a complex cascade of events. A l though multiple mechanisms may be involved, it appears that focal proteolytic activity is needed for extracellular matrix (ECM) remodeling and s u bsequent invasion. The plasminogen-plasmin system directly or, by activating matrix metalloproteinases (MMPs) has been implicated in the proteolytic remodeling of ECM. Annexin II (Ann II), a newly identified endothelial cell surface protein, is a co-receptor for plasminogen (PLG) and its activator, tissue plasminogen activator (t-PA). Ann II increases the catalytic efficiency of plasmin generation up to 60-fold over baseline in a purified protein system. We have employed C6 rat glioma cells, a well-defined in vitro model of human high grade glioma to study the potential role of Ann II in plasmin - mediated invasion. Preliminary in vitro data suggest that C6 cells abundantly express annexin II (Ann II), enhance plasmin generation in functional studies and mediate t-PA-dependent migration of C6 cells through both collagen and laminin matrices. Also, the invading edges of high grade human gliomas show strong positive staining for Ann II in the tumor cells. Based upon these preliminary data, this project will test the hypothesis that Ann II plays a role in plasmin - mediated high grade glioma invasion. The research will focus on defining the role of Ann II in vitro using invasion and matrix degradation assays, radiolabeled binding assays, specific functional assays and substrate zymography. Also, the hypothesis will be tested in an in vivo system with stereotactic injection of C6/lac Z cells into Fischer rat brains to produce tumors and to inhibit invasion with anti-Ann II antibodies and anti-sense Ann II constructs. Human brain tumor sections will be studied immunohistochemically for Ann II, t-PA expression and plasmin activity. By understanding mechanisms of invasion, it may be possible to devise novel therapeutic approaches to brain tumors specifically targeted to limit Ann II - mediated invasion. These studies could also have far reaching implications for the diagnosis and treatment of other locally invasive and metastatic tumors in a wide variety of settings. The principal investigator for this application is a board certified pediatrician, who during the process of training in pediatric hematology/oncology has spent 2 years in a vascular biology laboratory under the direction of Dr. Katherine A. Hajjar. The proposed plan will continue under her supervision at Weill Medical College of Cornell University. Her lab is part of a Specialized Center for Thrombosis Research and a Program Project in Vascular Biology, and is well equipped to carry out the investigations. Apart from weekly lab meetings to discuss individual projects, weekly research seminars and journal clubs provide an opportunity to meet with other investigators at the medical college and exposure to new ideas. Dr. Hajjar is also very accessible for individual weekly meetings when the need arises. T h i s environment will provide excellent training for a developing physician-researcher.