GANGLIOSIDE SIGNALING CASCADES FOR GLIOMA GROWTH

神经胶质瘤生长的神经节苷脂信号级联

• 批准号: 2696340
• 负责人: Arfaan Rampersaud
• 金额: $ 10.45万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-01 至 2003-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2696340
• 关键词: biological signal transduction; cell line; cell proliferation; enzyme activity; gangliosides; glioma; lipid biosynthesis; membrane activity; neoplastic growth; oncogenes; phosphatidylinositol 3 kinase; protein kinase; tissue /cell culture; transfection; western blottings

DESCRIPTION: (adapted from the investigator's abstract) Gangliosides are potent modulators of cell growth and could have profound effects on glioma proliferation. The general hypothesis is that gangliosides can stimulate glioma proliferation by activating specific signal transduction pathways. This is based on their finding that exogenous treatment of U-1242 MG glioma cells with ganglioside GM I stimulated DNA synthesis by a signaling mechanism involving the rapid activation of the extracellular signal-regulated protein kinase 2 (Erk2) and p70 S6 kinase (p70s6k). They will use use these cells as a model for studying the mechanisms by which gangliosides stimulate signal transduction, and believes the studies should clarify the role of gangliosides in cell proliferation and this is important in human brain tumors. In Specific Aim 1 he will characterize ganglioside interactions at and within the cell surface and relate these to activation of the Erk2 and p70s6k signaling cascades. He will use metabolic inhibitors to test whether endogenous ganglioside biosynthesis is important for signaling by exogenous GM 1. He will also test whether activation of Erk2 correlates with the stable association of GM l with cell surface proteins or with the insertion of GM I into the membrane. Based on studies with wortmannin, a specific inhibitor of phosphatidylinositol 3'-kinase, (PI3K), he proposes that GM I activates PI3K. In Specific Aim 2 he will measure GM1stimulated in vivo production of 3-phosphoinositides to estimate PI3K activation and determine the effects of tyrosine kinase inhibitors and G-protein inhibitors on this activity. In part b he will identify GMI-stimulated molecules that regulate PI3K using biochemical, immunological and molecular approaches. In part c he will create cells that are defective for PI3K activation and use them for studying GM1 -mediated activation of Erk2 and p70 s6k. GM1 stimulates Erk2 by a mechanism involving activation of the Raf-1 oncoprotein as well as stimulates p70s6k by an uncharacterized pathway. In Specific Aim 3, he will use genetic and biochemical approaches to examine whether GM1 stimulates Ras, a well known activator of Raf-1. He will also use novel Raf mutants and phosphoamino acid profiles to to identify novel GM1-stimulated regulation of Raf. He will also use in vitro kinase assays to test whether GM1 activates p70s6k through the serine/threonine kinase Akt.

描述：（根据调查人员的摘要改编）神经节是 有效的细胞生长调节剂，可能对神经胶质瘤产生深远影响 增殖。 一般假设是神经节苷脂可以刺激 通过激活特定的信号转导途径，神经胶质瘤增殖。 这是基于他们发现的U-1242 mg神经胶质瘤的外源治疗 神经节苷脂GM I通过信号传导刺激DNA合成的细胞 涉及细胞外快速激活的机制 信号调节的蛋白激酶2（ERK2）和P70 S6激酶（P70S6K）。 他们 将使用这些细胞作为研究机制的模型 神经毒剂刺激信号转导，并认为研究应 阐明神经节苷脂在细胞增殖中的作用，这很重要 在人脑肿瘤中。 在特定目标1中，他将在和 在细胞表面内，并将其与ERK2的激活相关联 P70S6K信号级联。 他将使用代谢抑制剂测试是否 内源性神经节苷脂生物合成对于通过外源性信号传导很重要 GM 1。他还将测试ERK2的激活是否与 GM L与细胞表面蛋白或插入的稳定关联 通用汽车i进入膜。 基于对Wortmannin的研究 磷脂酰肌醇3'-激酶（PI3K）的抑制剂，他提出GM I 激活PI3K。 在特定目标2中，他将测量体内刺激的GM1 生产3-磷酸肌醇以估计PI3K激活并确定 酪氨酸激酶抑制剂和G蛋白抑制剂对此的影响 活动。 在B部分中，他将确定调节的GMI刺激的分子 PI3K使用生化，免疫和分子方法。 在第c部分 他将创建用于PI3K激活有缺陷的细胞，并将其用于 研究GM1介导的ERK2和P70 S6K的激活。 GM1通过涉及RAF-1激活的机制刺激ERK2 通过未表征的途径刺激牙齿蛋白以及刺激P70S6K。 在 特定目的3，他将使用遗传和生化方法检查 GM1是否刺激RAF-1的众所周知的激活剂Ras。 他也会 使用新型的RAF突变体和磷酸氨基酸轮廓来识别新型 GM1刺激的RAF调节。他还将使用体外激酶测定 测试GM1是否通过丝氨酸/苏氨酸激酶AKT激活p70s6k。