ANNEXIN II & PLASMIN MEDIATED HIGH GRADE GLIOMA INVASION

描述(申请人描述)：恶性原发脑瘤， 尤其是胶质瘤，其特点是有侵袭周围环境的倾向。 脑结构导致高局部复发率和沮丧的 临床结果。入侵过程是一系列复杂的事件。 A L虽然可能涉及多种机制，但似乎焦点 细胞外基质(ECM)重塑和蛋白水解酶活性是必需的 S随后发动了入侵。纤溶酶原-纤溶酶系统直接或通过 激活基质金属蛋白酶(MMPs)被认为与 细胞外基质蛋白水解性重塑。新鉴定的膜联蛋白II(Ann II) 内皮细胞表面蛋白，是纤溶酶原(PLG)和 其激活物，组织型纤溶酶原激活剂(t-PA)。ANN II增加了 纤溶酶生成的催化效率高达基线的60倍 纯化蛋白系统。我们使用了C6大鼠胶质瘤细胞，它是一种定义明确的 人工神经网络在人脑高级别胶质瘤体外模型中的作用 II在纤溶酶介导的侵袭中。初步的体外数据表明，C6 细胞大量表达膜联蛋白II(ANN II)，促进纤溶酶的产生 C6细胞的功能研究及其介导t-PA依赖的迁移 胶原蛋白和层粘连蛋白基质。此外，高品位的侵袭边缘 人脑胶质瘤细胞呈ANN II强阳性染色。 基于这些初步数据，该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发挥作用。这个 研究将集中于确定ANN II在体外使用侵袭和 基质降解分析、放射性标记结合分析、特定功能 检测和底物酶谱分析。此外，这一假设将在In中进行测试 Fischer大鼠立体定向注射C6/lac Z细胞的体内系统 用抗ANN II抗体抑制脑部肿瘤的侵袭 和反义ANN II构建。人脑肿瘤切片将被研究 免疫组织化学检测ANN II、t-PA表达和纤溶酶活性。通过 了解入侵机制，就有可能设计出新的 专门针对限制ANN II的脑肿瘤的治疗方法- 居间入侵。这些研究也可能产生深远的影响。 用于其他局部侵袭和转移的诊断和治疗 肿瘤在各种各样的环境中。 这项申请的首席调查员是经过认证的董事会。 儿科医生，在儿科培训过程中 血液学/肿瘤学在一个血管生物实验室工作了两年 凯瑟琳·A·哈贾尔博士的方向。拟议的计划将继续执行 在她的监督下，在康奈尔大学威尔医学院。她的实验室 是一个专门的血栓研究中心和一个计划项目的一部分 拥有血管生物学方面的专业知识，并具备开展研究的能力。 除了每周的实验室会议讨论个别项目外，每周的研究 研讨会和杂志俱乐部提供了一个与其他人见面的机会 医学院的研究人员和接触到了新的想法。Hajjar博士是 当需要时，个人每周会议也非常方便。 S的环境将为一个不断发展的人提供良好的培训 内科医生兼研究员。

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.