Regulation of Cellular Survival, Size and Metabolism

细胞存活、大小和代谢的调节

• 批准号: 6920805
• 负责人: David R Plas
• 金额: $ 15.95万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6920805
• 关键词: BCL2 gene /protein; affinity chromatography; apoptosis; biological signal transduction; cell cycle; cell morphology; enzyme substrate; flow cytometry; gene expression; genetic regulation; growth factor; hematopoietic stem cells; immunoprecipitation; interleukin 3; mass spectrometry; neoplasm /cancer genetics; phosphatidylinositol 3 kinase; phosphoproteins; phosphorylation; polymerase chain reaction; proteasome; protein degradation; protooncogene; tumor suppressor genes

DESCRIPTION (provided by applicant): Cancer develops as a result of uncontrolled cell proliferation coupled with defects in the induction of programmed cell death. Two classes of genes that have been shown to prevent cell death are the pro-survival Bcl-2 family members, and the serine-threonine kinase Akt. Previous work with Akt has demonstrated that cells surviving in an Akt-dependent manner are characterized by increased cell size and a reliance on increased cell metabolism. The molecular mechanisms by which Akt controls cell size and metabolism are unclear. The tuberous sclerosis gene TSC2 is a potential substrate of Akt, and has been shown to regulate cell size when expressed together with its binding partner, TSC1. In this proposal, experiments will be performed to determine the molecular targets for Akt-dependent increases in cell size, metabolism, and survival. The effects of the expression of hamartin and tuberin on these same processes will be assessed, as well as the possibility that TSC2 is an Akt substrate. Specific aims: 1. Identify the major downstream targets of Akt in the control of cell size and survival. A. Determine the major phosphoproteins induced in hematopoietic cells by activation of Akt. B. Determine which of the major downstream targets of Akt transduce signals that maintain cellular viability, metabolism and size in the absence of growth factor. C. Characterize Akt-induced degradation of its substrates. 2. Test the role of the tuberous sclerosis genes in regulating cell size and survival in hematopoietic cells. A. Characterize changes in TSC1 and TSC2 expression in hematopoietic cells upon growth factor withdrawal. B. Express TSC1 and TSC2 in control, Bcl-xL- and activated Akt-expressing cells, and measure changes in cell cycle, size, viability and metabolism in the presence and absence of growth factor. C. Determine if TSC1 and TSC2 contribute to Akt effects on cell size or survival. Test the importance of the potential Akt phosphorylation sites in tuberin. Together, these studies will help define the roles of the proto-oncogene Akt and the tumor suppressor genes TSC1 and TSC2 in the deregulation of cell metabolism in cancers associated with these genes.

描述（由申请人提供）：癌症的发生是由于不受控制的细胞增殖加上诱导程序性细胞死亡的缺陷造成的。 两类已被证明可以防止细胞死亡的基因是促存活 Bcl-2 家族成员和丝氨酸-苏氨酸激酶 Akt。 之前对 Akt 的研究表明，以 Akt 依赖性方式存活的细胞的特点是细胞大小增加以及对细胞代谢增加的依赖。 Akt 控制细胞大小和代谢的分子机制尚不清楚。 结节性硬化症基因 TSC2 是 Akt 的潜在底物，已被证明在与其结合伴侣 TSC1 一起表达时可调节细胞大小。 在该提案中，将进行实验以确定 Akt 依赖性细胞大小、代谢和存活增加的分子靶点。 将评估错构蛋白和马铃薯蛋白表达对这些相同过程的影响，以及 TSC2 是 Akt 底物的可能性。 具体目标： 1. 确定 Akt 在控制细胞大小和存活方面的主要下游靶标。 A. 确定由 Akt 激活在造血细胞中诱导的主要磷蛋白。 B. 确定 Akt 的哪些主要下游靶标可转导在缺乏生长因子的情况下维持细胞活力、代谢和大小的信号。 C. 表征 Akt 诱导的底物降解。 2. 测试结节性硬化症基因在调节造血细胞的细胞大小和存活中的作用。 A. 描述停止生长因子后造血细胞中 TSC1 和 TSC2 表达的变化。 B. 在对照、Bcl-xL 和活化的 Akt 表达细胞中表达 TSC1 和 TSC2，并测量在存在和不存在生长因子的情况下细胞周期、大小、活力和代谢的变化。 C. 确定 TSC1 和 TSC2 是否有助于 Akt 对细胞大小或存活的影响。 测试马铃薯球蛋白中潜在 Akt 磷酸化位点的重要性。 总之，这些研究将有助于确定原癌基因 Akt 以及肿瘤抑制基因 TSC1 和 TSC2 在与这些基因相关的癌症中细胞代谢失调中的作用。