STUDIES OF THE FOS ONCOGENE

FOS癌基因的研究

• 批准号: 6489342
• 负责人: TOM CURRAN
• 金额: $ 40.33万
• 依托单位: ST. JUDE CHILDREN'S RESEARCH HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-01 至 2004-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6489342
• 关键词: cell transformation; embryonic stem cell; fos protein; gene expression; genetically modified animals; laboratory mouse; methylation; microarray technology; oncogenes; oxidation reduction reaction; point mutation; representational difference analysis

The discovery of oncogenes revolutionized analysis of the molecular bases of cancer. Oncogenes provided starting points for molecular dissection of the signaling pathways that govern normal cell growth and for elucidation of the events that lead to oncogenesis. The fos oncogene is responsible for induction of osteosarcomas and cell transformation by the Finkel-Biskis-Jinkins murine sarcoma virus. Its protein product, Fos, functions as a component of the inducible mammalian transcription factor AP 1. Induction of c-fos expression is associated with mitogenesis, differentiation, apoptosis and excitation of neurons. It is believed to participate in complex signal transduction networks that couple extracellular stimuli to long-term cellular responses by regulating gene expression. Transformation by fos is thought to be a consequence of inappropriate regulation of gene expression. Three major specific aims are addressed in this application. The first concerns the identification and characterization of fos target genes responsible for cell transformation by Representational Difference Analysis and cDNA array hybridization approaches. In the second specific aim we will follow up preliminary studies demonstrating that DNA 5-methylcytosine transferase-1 (dnmt1) is a fos target gene involved in cell transformation. We plan to identify genes that are methylated by dnmt1 in fos transformed cells and analyze their contribution to transformation. The third specific aim concerns the role of reduction/oxidation (redox) in the regulation of Fos function and cell growth. Previously, we demonstrated that the bifunctional redox/endonuclease gene, ref-1, regulates the DNA binding activity of Fos through a conserved cysteine residue in the DNA binding domain. Disruption of the Ref-1 gene in mice causes early embryonic lethality. We will introduce point mutations into Ref-1, by homologous recombination in embryonic stem cells that ablate the redox and nuclease functions of Ref-1 independently. These cells will be used to generate mutant mice and cell lines that will be used to analyze the role of Ref-1 in modulating AP1 activity and cell growth.

癌基因的发现彻底改变了癌症分子基础的分析。 癌基因为控制正常细胞生长的信号通路的分子解剖和阐明导致肿瘤发生的事件提供了起点。 fos 癌基因负责芬克尔-比斯基斯-金金斯鼠肉瘤病毒诱导骨肉瘤和细胞转化。 其蛋白质产物 Fos 是诱导型哺乳动物转录因子 AP 1 的组成部分。c-fos 表达的诱导与神经元的有丝分裂、分化、凋亡和兴奋相关。 据信它参与复杂的信号转导网络，通过调节基因表达将细胞外刺激与长期细胞反应结合起来。 fos 的转化被认为是基因表达调节不当的结果。 本申请解决了三个主要的具体目标。 第一个涉及通过代表性差异分析和 cDNA 阵列杂交方法对负责细胞转化的 fos 靶基因进行鉴定和表征。 在第二个具体目标中，我们将跟进初步研究，证明 DNA 5-甲基胞嘧啶转移酶-1 (dnmt1) 是参与细胞转化的 fos 靶基因。 我们计划鉴定 fos 转化细胞中被 dnmt1 甲基化的基因，并分析它们对转化的贡献。 第三个具体目标涉及还原/氧化（氧化还原）在 Fos 功能和细胞生长调节中的作用。此前，我们证明双功能氧化还原/核酸内切酶基因 ref-1 通过 DNA 结合域中保守的半胱氨酸残基调节 Fos 的 DNA 结合活性。 小鼠 Ref-1 基因的破坏会导致早期胚胎死亡。 我们将通过胚胎干细胞中的同源重组将点突变引入 Ref-1，从而独立地消除 Ref-1 的氧化还原和核酸酶功能。 这些细胞将用于生成突变小鼠和细胞系，用于分析 Ref-1 在调节 AP1 活性和细胞生长中的作用。