E2F3: a suppressor of centrosome amplification

E2F3：中心体扩增的抑制因子

• 批准号: 6891455
• 负责人: Harold I Saavedra
• 金额: $ 15.71万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6891455
• 关键词: DNA replication; aneuploidy; breast neoplasms; carcinogenesis; cell cycle; cell growth regulation; cell proliferation; centrosome; gene induction /repression; genetic models; genetically modified animals; laboratory mouse; natural gene amplification; neoplasm /cancer genetics; neoplastic cell; neoplastic transformation; postdoctoral investigator; transcription factor; tumor suppressor proteins

DESCRIPTION (provided by applicant): The overall goal of this K01 proposal is to allow Harold I. Saavedra, Ph.D., under the mentorship of Gustavo Leone, Ph.D. to transition from a postdoctoral fellowship to the establishment of his own independent laboratory in an academic institution. The study of the Rb/E2F pathway is crucial to the understanding of cancer, since components of this pathway are de-regulated in almost all human tumors. One of the central components of the Rb/E2F pathway is the E2F3 transcription factor, which plays a key role in cell cycle progression. The E2F3 locus codes for two transcripts, E2F3a and E2F3b, whose individual functions are presently unknown. We show that gene knock-out of E2F3, which included knocking-out of E2F3a and E2F3b, leads to slower growth rates, centrosome amplification and aneuploidy. Our hypothesis is that the uncoupling of the centrosome cycle and the cell cycle, triggered by the loss of E2F3 function, may ultimately lead to cancer. To explore this hypothesis we propose the following specific aims: 1. To unravel the individual contributions of E2F3a and E2F3b towards ceil cycle control, suppression of centrosome amplification and aneuploidy. SiRNAs will be introduced into mouse embryonic fibroblasts to knock-down the expression of E2F3a and E2F3b. We will determine the growth characteristics of those knock-downs, and their individual contributions towards centrosome amplification and aneuploidy. 2. To explore, using a centrin-GFP transgenic mouse, whether loss of E2F3 leads to centrosome amplification in vivo. We will introduce a conditional allele of E2F3 into centrin-GFP mice. Conditional deletion of E2F3 in mammary epithelial cells will be achieved by crossing those mice with WAP-CRE mice. Frequencies of centrosome amplification will be calculated from sections of those mammary glands. 3. To explore the potential role of the myclE2F pathway in centrosome amplification and mammary carcinogenesis. We will generate WAP-myc/centrin-GFP mice and determine progression from expression of myc to centrosome amplification, aneuploidy and tumorigenesis. We will also explore whether loss of E2F3 cooperates with myc to accelerate mammary tumorigenesis. The results obtained from this K01 proposal will be invaluable to the understanding of the relationship between centrosome amplification, aneuploidy and carcinogenesis in vivo, and to whether genomic instability is a cause or a consequence of tumorigenesis.

描述（由申请人提供）：该 K01 提案的总体目标是让 Harold I. Saavedra 博士在 Gustavo Leone 博士的指导下进行研究。从博士后过渡到在学术机构建立自己的独立实验室。 Rb/E2F 通路的研究对于理解癌症至关重要，因为该通路的组成部分在几乎所有人类肿瘤中都不受调控。 Rb/E2F 通路的核心成分之一是 E2F3 转录因子，它在细胞周期进程中发挥着关键作用。 E2F3基因座编码两个转录本，E2F3a和E2F3b，其各自的功能目前未知。我们发现，E2F3 的基因敲除，包括 E2F3a 和 E2F3b 的敲除，会导致生长速度减慢、中心体扩增和非整倍性。我们的假设是，由 E2F3 功能丧失引发的中心体周期和细胞周期的解偶联可能最终导致癌症。为了探索这一假设，我们提出以下具体目标： 1. 阐明 E2F3a 和 E2F3b 对细胞周期控制、中心体扩增和非整倍性抑制的个体贡献。 siRNA 将被引入小鼠胚胎成纤维细胞中以敲低 E2F3a 和 E2F3b 的表达。我们将确定这些敲低的生长特征，以及它们对中心体扩增和非整倍性的个体贡献。 2. 利用centrin-GFP转基因小鼠探讨E2F3缺失是否会导致体内中心体扩增。我们将 E2F3 的条件等位基因引入 centrin-GFP 小鼠中。通过将这些小鼠与 WAP-CRE 小鼠杂交，可以实现乳腺上皮细胞中 E2F3 的条件性删除。中心体扩增的频率将从这些乳腺的切片中计算出来。 3. 探讨myclE2F通路在中心体扩增和乳腺癌发生中的潜在作用。我们将生成 WAP-myc/centrin-GFP 小鼠，并确定从 myc 表达到中心体扩增、非整倍性和肿瘤发生的进展。我们还将探讨E2F3的缺失是否与myc协同加速乳腺肿瘤的发生。从这个 K01 提案中获得的结果对于理解中心体扩增、非整倍性和体内致癌之间的关系，以及基因组不稳定性是否是肿瘤发生的原因或结果具有非常宝贵的价值。