The Role of JNK in Glial Tumor Pathogenesis

JNK 在胶质瘤发病机制中的作用

• 批准号: 6732178
• 负责人: ALBERT J. WONG
• 金额: $ 31.44万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-04-01 至 2007-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6732178
• 关键词: 3T3 cells; JUN kinase; angiogenesis; apoptosis; astrocytes; athymic mouse; biological signal transduction; carcinogenesis; cell proliferation; epidermal growth factor; glioblastoma multiforme; growth factor receptors; guanine nucleotide binding protein; guanosinetriphosphatases; human tissue; immunoprecipitation; mass spectrometry; mitogen activated protein kinase; neoplastic growth; platelet derived growth factor; receptor expression; thin layer chromatography; transcription factor; western blottings

DESCRIPTION (provided by applicant): Our long term goals are to understand the molecular mechanisms underlying glioblastoma multiforme, the most common and deadly among human brain tumors. The EGF receptor has been strongly implicated and much research on its downstream signaling has focused on the ERK signaling module. Unexpectedly, our work has instead led us to study a pathway not commonly considered downstream of the EGF receptor or in tumorigenesis, the JNK pathway. We have found that 86 percent of primary glioblastoma tumors show activation of a 54 kDa JNK isoform. EGF induces strong JNK activation in 69 percent of cell lines derived from glioblastoma tumors but only weak activation was observed in 6 normal cell lines. Further work in two tumor cell lines has indicated that JNK is important for anchorage independent growth and the prevention of apoptosis. We hypothesize that an important difference between glioblastoma tumors and normal tissues is that EGF receptor signals are also directed towards the JNK pathway. The goals of this application are to further study the mechanisms by which JNK becomes activated and how it contributes to multiple phenotypes. In Specific Aim #1, we will examine the mechanisms underlying the enhanced EGF induced activation of JNK seen in glioblastoma cell lines. Several points at which signals can be directed towards the JNK signaling module will be examined: 1) the small GTPases, Rac and Cdc42; 2) PI 3-kinase; and 3) Gab1. These molecules will be tested for increased activity/binding following EGF addition in glioblastoma cell lines as compared to normal astrocyte cell lines. Dominant negative versions of these molecules will be used to confirm their roles in JNK activation. In Specific Aim #2, we will determine which JNK isoform the 54 kDa form corresponds to using RNase protection. Next, we will identify the mechanisms by which it became preferentially phosphorylated. Most importantly, we will determine what properties this isoform has that might contribute to tumorigenesis. The localization of the 54 kDa isoform will be studied in tumor sections and the transcription factors that bind to this isoform in tumors will also be studied. In Specific Aim #3, we will evaluate the relative contribution of JNK and ERK to glial tumorigenesis. The notion that JNK contributes to tumorigenesis is relatively new and not well studied, especially in animal models, but there is a much more extensive literature on the contribution of ERK to tumorigenesis. Thus, we will attempt to clarify the relative contribution of these two signaling modules to these critical phenotypes in vivo: 1) tumor formation in athymic mice, 2) angiogenesis, 3) cell proliferation, and 4) prevention of apoptosis. This work will further enhance our knowledge of this novel signaling pathway in this human cancer and provide new avenues for diagnostics and therapeutics.

描述(由申请人提供)：我们的长期目标是了解 多形性胶质母细胞瘤的分子机制是最常见和 在人类脑瘤中是致命的。EGF受体已经被强烈地牵连在一起 而对其下游信号的研究主要集中在ERK信号上 模块。出乎意料的是，我们的工作反而让我们研究了一条不是 通常被认为在EGF受体下游或在肿瘤发生中，JNK 路径。我们发现86%的原发胶质母细胞瘤表现出 激活一个54 kDa的JNK亚型。表皮生长因子诱导69例巨噬细胞JNK强激活 来自胶质母细胞瘤的细胞系的百分比，但只有微弱的激活 在6个正常细胞系中均有表达。在两种肿瘤细胞系中的进一步研究已经 表明JNK对锚地独立生长具有重要意义 防止细胞凋亡。我们假设一个重要的区别是 胶质母细胞瘤和正常组织中的EGF受体信号也 指向JNK路径。此应用程序的目标是进一步 研究JNK被激活的机制以及它如何对 多种表型。在具体目标#1中，我们将检查这些机制 增强型EGF诱导胶质母细胞瘤细胞JNK活化的机制 台词。可以将信号指向JNK的几个点 将研究信号模块：1)小GTP酶、RAC和CDC42；2)PI 3)GAB1。这些分子将被测试是否增加了 胶质母细胞瘤细胞系加入EGF后活性/结合的比较 到正常的星形胶质细胞系。这些分子的显性负性版本 将用于确认他们在JNK激活中的角色。在具体目标2中，我们 将使用RNase确定54 kDa形式对应的JNK亚型 保护。接下来，我们将确定它形成的机制 优先被磷酸化。最重要的是，我们将决定 这种异构体所具有的特性可能有助于肿瘤的发生。这个 54 kDa异构体的定位将在肿瘤切片和 在肿瘤中结合这种异构体的转录因子也将被研究。 在具体目标3中，我们将评估JNK和ERK的相对贡献 神经胶质瘤的发生。JNK对肿瘤发生有贡献的观点是 相对较新，研究较少，特别是在动物模型中，但有 关于ERK在肿瘤发生中的作用的更广泛的文献。 因此，我们将试图澄清这两者的相对贡献 体内这些关键表型的信号模块：1)肿瘤形成 无瘤小鼠，2)血管生成，3)细胞增殖，4)预防 细胞凋亡。这项工作将进一步增强我们对这一新颖信号的了解 为人类癌症的诊断和治疗提供了新的途径 治疗学。