REPRESSION BY C SKI AND MELANOMA PROGRESION

C SKI 的抑制和黑色素瘤的进展

• 批准号: 6514289
• 负责人: ESTELA E MEDRANO
• 金额: $ 31.82万
• 依托单位: BAYLOR COLLEGE OF MEDICINE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2005-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6514289
• 关键词: biological signal transduction; gene expression; gene induction /repression; genetic promoter element; genetic transcription; guanine nucleotide binding protein; human tissue; melanocyte; melanoma; neoplasm /cancer genetics; neoplastic process; oncoprotein p21; oncoproteins; p53 gene /protein; protooncogene; tissue /cell culture; transcription factor; transforming growth factors

DESCRIPTION: (adapted from the investigator's abstract) the major goal of this proposal is to define the role of the protein SKI in human melanomas. SKI expression is highly elevated in melanomas compared to normal melanocytes. Their preliminary data demonstrates that SKI participates in the TGF-B signaling pathway and in the DNA damage response. He has found that SKI physically associates with the transcriptional co-activator proteins Smad2 and Smad3, two members of the TFG-B signaling pathway. In addition, forced expression of SKI results in inactivation of G1 checkpoints downstream from the protein p53. He proposes to determine the role of SKI in the TGF-B pathway and to determine the molecular mechanism(s) by which SKI interferes with the DNA-damage response in melanocytes and melanoma cells. Specifically, he will: (1) Define the molecular and biological activities of SKI in the TGF-G pathway by a) analyzing the activities of SKI/Smads complexes on TFG-B responsive promoters; b) determining whether SKI perturbs hetero-oligomer formation between Smad2 and Smad3 and the common-mediator Smad4; c) determining whether forced expression of SKI converts TGF-B-sensitive, normal human melanocytes to TGF-B-resistance and/or whether SKI represses TGF-B-mediated gene activation in vivo. (2) Analyze the molecular mechanism(s) whereby SKI suppresses p21 (Waf-1/SDI/Cip/1) expression. For that, he will determine whether; a) SKI interferes with the DNA-binding activity of the protein p53; b) SKI disrupts association of p53 with transcriptional activators; c) SKI interferes with Smad and p53 activity on the p21 promoter. 3) Explore the long-term consequences of SKI activity by determining whether forced expression of SKI results in chromosome instability in DNA-damaged cells. He will analyze whether these cells show a) abnormal centrosome amplifications; b) changes in Cyclin-Cdk-Cdk-I complexes that predispose cells to unrestricted growth. The studies proposed should underscore the role of SKI as a potent oncogenic protein in human melanomas and lay down foundations for future intervention therapies.

描述：（改编自研究者的摘要）该提案的主要目标是确定蛋白质 SKI 在人类黑色素瘤中的作用。与正常黑色素细胞相比，黑色素瘤中 SKI 的表达高度升高。他们的初步数据表明，SKI 参与 TGF-B 信号通路和 DNA 损伤反应。他发现 SKI 在物理上与转录共激活蛋白 Smad2 和 Smad3，TFG-B 信号通路的两个成员。此外，SKI 的强制表达会导致 p53 蛋白下游的 G1 检查点失活。他提议确定 SKI 在 TGF-B 途径中的作用，并确定 SKI 干扰黑色素细胞和黑色素瘤细胞 DNA 损伤反应的分子机制。具体来说，他将： (1) 通过分析 SKI/Smads 复合物对 TFG-B 响应启动子的活性来定义 SKI 在 TGF-G 途径中的分子和生物学活性； b) 确定 SKI 是否扰乱 Smad2 和 Smad3 以及共同介体 Smad4 之间的异源寡聚体形成； c)确定SKI的强制表达是否将TGF-B敏感的正常人黑素细胞转化为TGF-B抗性和/或SKI是否在体内抑制TGF-B介导的基因激活。 (2)分析SKI抑制p21(Waf-1/SDI/Cip/1)表达的分子机制。为此，他将决定是否； a) SKI 干扰蛋白质 p53 的 DNA 结合活性； b) 滑雪中断 p53 与转录激活因子的关联； c) SKI 干扰 p21 启动子上的 Smad 和 p53 活性。 3) 通过确定 SKI 的强制表达是否会导致 DNA 损伤的染色体不稳定，探索 SKI 活性的长期后果 细胞。他将分析这些细胞是否表现出 a) 异常的中心体扩增； b) 细胞周期蛋白-Cdk-Cdk-I 复合物的变化使细胞易于不受限制地生长。 拟议的研究应强调 SKI 作为人类黑色素瘤中有效致癌蛋白的作用，并为未来的干预疗法奠定基础。