REGULATION OF ORNITHINE DECARBOXYLASE BY PHORBOL ESTERS

佛波酯对鸟氨酸脱羧酶的调节

• 批准号: 6375796
• 负责人: ANDREW P BUTLER
• 金额: $ 20.04万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-03-01 至 2003-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6375796
• 关键词: acetylation; chemical carcinogenesis; enzyme induction /repression; histones; nucleic acid sequence; oncogenes; ornithine decarboxylase; phorbols; reporter genes; site directed mutagenesis; tissue /cell culture; transcription factor; transfection

Induction of ornithine decarboxylase (ODC) is one of the earliest changes in gene expression elicited by phorbol ester tumor promoters such as 12-O-tetradecanoylphorbol-13-acetate (TPA), and is a common feature of multiple classes of tumor promoters. Inhibition of ODC blocks tumor progression in experimental models, and may have clinical applicability. In addition, aberrant overexpression of ODC can be tumorigenic in vitro. The overall goal of this proposal is to understand how the transcription of ODC is regulated by tumor promoters and oncogenes. Towards this goal, the following specific aims will be pursued: 1. Identify DNA sequence elements required for transcriptional regulation of ODC by TPA and oncogenes. This will be accomplished by transient expression analysis of ODC reporter genes containing linker-scanning or point-mutations of the proximal promoter region. 2. Characterize the role of TAFII250 in regulation of ODC promoter activity. The major emphasis of this Aim will be characterization of the putative role of TAFII250 in determining responses of the ODC promoter to tumor promoters. 3. Determine the relationship between histone acetylation and ODC induction. The rationale for this aim is based on the effects we observed with the histone deacetylase inhibitor trichostatin A, as well as the apparent involvement of TAFII250 and a p300-related protein (both of which are histone acetylases) in ODC regulation. 4. Determine the role of transcriptional cofactors in ODC regulation. This Aim will use mutants of the Adenovirus 12S E1A protein as a tool to determine the role of the p300/CBP family of co-activators in ODC transcription. In addition, we will analyze ODC expression in cells co-transfected with p300. Taken together, these studies should provide new insight into the mechanisms by which tumor promoters and oncogenes influence ODC regulation and corrupt patterns of gene expression during carcinogenesis.

鸟氨酸脱羧酶（ODC）的诱导是佛波尔酯肿瘤启动子引起的基因表达的最早变化之一，例如12-O-tetradecanoylphorbol-13-13-乙酸酯（TPA），并且是多种肿瘤启动子的常见特征。 ODC阻断实验模型中肿瘤进展的抑制作用，可能具有临床适用性。 另外，ODC的异常过表达在体外可能是肿瘤性的。 该提案的总体目标是了解ODC的转录如何受肿瘤启动子和癌基因的调节。 为了实现这一目标，将追求以下特定目标：1。确定TPA和Oncogenes对ODC进行转录调控所需的DNA序列元素。 这将通过对包含近端启动子区域接头扫描或点突变的ODC报告基因的瞬时表达分析来实现。 2。表征TAFII250在ODC启动子活性调节中的作用。 该目标的主要重点是表征TAFII250在确定ODC启动子对肿瘤启动子的反应中的推定作用。 3。确定组蛋白乙酰化与ODC诱导之间的关系。 此目的的基本原理是基于我们观察到的组蛋白脱乙酰基酶抑制剂trichostatin A的影响，以及TAFII250和P300相关蛋白（两者都是组蛋白乙酰基酶）在ODC调节中的明显参与。 4。确定转录辅因子在ODC调节中的作用。 该目标将使用腺病毒12S E1A蛋白的突变体作为确定共激活剂p300/cbp家族在ODC转录中的作用的工具。 此外，我们将分析与P300共转染的细胞中的ODC表达。 综上所述，这些研究应提供有关肿瘤启动子和癌基因在致癌过程中基因表达的调节和损坏模式的机制的新见解。