Glypican-1 in gliomagenesis

Glypican-1 在神经胶质瘤发生中的作用

• 批准号: 8803230
• 负责人: ANDREAS FRIEDL
• 金额: --
• 依托单位: WM S. MIDDLETON MEMORIAL VETERANS HOSP
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-04-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8803230
• 关键词: Age; Aneuploidy; Animals; Astrocytes; Biological Assay; Biology; Brain Neoplasms; CDKN2A gene; Cell Cycle; Cell Cycle Regulation; Cell surface; Cells; Common Neoplasm; Cyclin E; Cyclin-Dependent Kinase Inhibitor; DNA; DNA Damage; DNA Replication Damage; DNA biosynthesis; Data; Development; Diagnosis; Endothelial Cells; Event; Future; G1/S Transition; Genetic; Glial Fibrillary Acidic Protein; Glioma; Gliomagenesis; Glypican; Growth; Health; Heparan Sulfate Proteoglycan; Human; In Vitro; Laboratories; Lead; Malignant - descriptor; Mediator of activation protein; Morbidity - disease rate; Mus; Mutation; Neoplasms; Neuraxis; Neuroglia; Oncogenes; Pathway Analysis; Patients; Penetrance; Play; Population; Prevention; Process; Prognostic Marker; Proteoglycan; Relative (related person); Research Design; Resistance; Retinoblastoma Protein; Role; S Phase; Signal Pathway; Signaling Molecule; System; Testing; Therapeutic Intervention; Tissue Microarray; Transgenic Mice; Veterans; Virus Receptors; base; c-myc Genes; design; gain of function; human CDK2 protein; in vivo; in vivo Model; insight; killings; loss of function; mortality; nerve stem cell; novel; novel strategies; oncoprotein p21; outcome forecast; overexpression; ras Oncogene; research study; treatment strategy; tumorigenesis

DESCRIPTION (provided by applicant): Central nervous system gliomas cause morbidity and mortality by relentless growth and local invasion. High-grade gliomas typically kill patients within months after diagnosis. Despite advances in therapy, this dismal prognosis has not changed significantly. One of the hallmarks of glioma cells is their genetic instability, which contributes to progression and therapy resistance. A major barrier to the development of more effective glioma treatment strategies is the relative lack of understanding of the mechanisms underlying glioma development, progression and genetic instability. We have made a discovery that may offer a novel approach to the treatment of gliomas. Our laboratory discovered that glypican-1 (GPC1), a cell surface proteoglycan, is overexpressed in the vast majority of gliomas. Overexpression of GPC1 in vitro activates c-Myc and triggers the Skp2 autoinduction loop, which is characterized by the coordinated induction of E2F, Skp2, cyclin E and cyclin-dependent kinase 2 (CDK2) and the suppression of the cyclin-dependent kinase inhibitors (CKIs) p21 and p27. These coordinated changes in cell cycle regulators lead to G1-S-transition and DNA replication. In glioma cells and astrocytes, GPC1 overexpression also induces DNA re-replication resulting in DNA damage. Preliminary data indicate that the oncogene c-Myc plays is a major upstream mediator of these changes. We hypothesize that GPC1 is a potent regulator of the cell cycle and acts as an oncogene when overexpressed in glial cells. We propose to test this hypothesis by deciphering the signaling pathway of GPC1 in glioma cells and astrocytes and by determining the effect of GPC1 loss and overexpression on glioma development in vivo. Aim 1: Analyze the mechanism of Gpc1 in cell cycle regulation: We will analyze the effect of different GPC1 concentrations on DNA replication and cell cycle regulators in astrocytes and different glioma cells. A particular focus will be placed on GPC1 activity in the activation of c-Myc. In addition, we will employ a discovery strategy to identify GPC1 interaction partners. Aim 2: Analyze the ability of GPC1 to transform human astrocytes: Immortal and primary human astrocytes will be transduced to overexpress GPC1. The malignant potential of the cells will be assessed in in vitro transformation assay and with in vivo tumorigenesis experiments. Aim 3: Determine the role of GPC1 in glioma development and progression in vivo: The role of GPC1 in early gliomagenesis will be assessed using state-of-the-art in vivo models based on the RCAS tv-a viral receptor system. Using a gain-of-function approach, GPC1 will be overexpressed in neural progenitors and astrocytes to determine whether GPC1 is sufficient for glioma induction. Using a loss-of-function approach, genetically GPC1-deficient mice will be crossed with transgenic mice, which express activated ras oncogene in a astrocyte-specific manner and which develop high-grade gliomas with high penetrance and short latency. These experiments will reveal whether GPC1-deficient animals are protected from gliomagenesis. In addition, we will interrogate an existing tissue microarray to determine whether GPC1 overexpression is an independent prognostic marker in human glioma. Significance: The proposed studies are designed to offer novel insights into the biology of glioma development and progression and into the specific role of the proteoglycan GPC1 in these processes. The GPC1 signaling pathway may offer opportunities for therapeutic intervention by targeting either GPC1 itself or downstream mediators.

描述（由申请人提供）： 中枢神经系统神经胶质瘤通过无情的生长和局部入侵会导致发病率和死亡率。高级神经胶质瘤通常在诊断后的几个月内杀死患者。尽管在治疗方面取得了进步，但这种令人沮丧的预后并未发生重大变化。神经胶质瘤细胞的标志之一是它们的遗传不稳定性，这有助于进展和耐药性。开发更有效的神经胶质瘤治疗策略的主要障碍是对神经胶质瘤发育，进展和遗传不稳定机制的相对缺乏了解。我们做出了一个发现，可能为胶质瘤的治疗提供了一种新颖的方法。 我们的实验室发现，在绝大多数神经胶质瘤中，Glypican-1（GPC1）是一种细胞表面蛋白聚糖。 GPC1体外的过表达激活C-MYC并触发SKP2自诱导回路，其特征在于E2F，SKP2，Cyclin E E和Cyclin依赖性激酶2（CDK2）的协调诱导以及Cyclin依赖性激酶抑制剂抑制剂（CKIS）（CKIS）（CKIS）P21和P21和P21和P21和P27。这些协调的细胞周期调节剂变化导致G1-S-S-转换和DNA复制。在神经胶质瘤细胞和星形胶质细胞中，GPC1的过表达还会诱导DNA再复制，从而导致DNA损伤。初步数据表明，癌基因C-MYC戏剧是这些变化的主要上游介体。 我们假设GPC1是细胞周期的有效调节剂，当在神经胶质细胞中过表达时，它是癌基因。我们建议通过解释GPC1在神经胶质瘤细胞和星形胶质细胞中的信号传导途径，并确定GPC1损失和过表达对体内神经胶质瘤发育的影响来检验这一假设。 AIM 1：分析细胞周期调节中GPC1的机制：我们将分析不同GPC1浓度对星形胶质细胞和不同神经胶质瘤细胞中DNA复制和细胞周期调节剂的影响。在C-MYC激活中，将特别关注GPC1活性。此外，我们将采用发现策略来识别GPC1相互作用伙伴。 AIM 2：分析GPC1转化人类星形细胞的能力：不朽的和原发性人类星形胶质细胞将被转导为过表达GPC1。细胞的恶性潜力将在体外转化测定法和体内肿瘤发生实验中进行评估。 AIM 3：确定GPC1在胶质瘤发育和体内进展中的作用：将使用基于RCAS TV-A病毒受体系统的最新体内模型来评估GPC1在早期神经胶质作用中的作用。使用功能获得的方法，在神经祖细胞和星形胶质细胞中GPC1将过表达，以确定GPC1是否足以诱导神经胶质瘤。使用功能丧失方法，将与转基因小鼠跨基因GPC1缺陷小鼠，这些小鼠以星形胶质细胞特异性的方式表达激活的Ras癌基因，并形成具有高渗透率和短延迟的高级神经胶质瘤。这些实验将揭示缺乏GPC1的动物免受神经胶质作用的保护。此外，我们将询问现有的组织微阵列，以确定GPC1过表达是否是人神经胶质瘤中的独立预后标记。 意义：拟议的研究旨在为神经胶质瘤发育和进展的生物学提供新颖的见解，并为蛋白聚糖GPC1在这些过程中的特定作用中提供。 GPC1信号通路可能通过针对GPC1本身或下游介体来提供治疗干预的机会。