Selenium molecular signaling in human prostate cancer

人类前列腺癌中的硒分子信号传导

• 批准号: 6748976
• 负责人: CLEMENT C IP
• 金额: $ 37.04万
• 依托单位: ROSWELL PARK CANCER INSTITUTE CORP
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6748976
• 关键词: DNA binding protein; biological signal transduction; cancer prevention; cell line; chemoprevention; cytogenetics; gel mobility shift assay; gene expression; gene induction /repression; genetic regulation; genetic transcription; growth inhibitors; immunoprecipitation; microarray technology; molecular biology; molecular cloning; polymerase chain reaction; prostate neoplasms; selenium; site directed mutagenesis; transcription factor; western blottings

DESCRIPTION (provided by applicant): Scanty information is currently available on the molecular mechanism of selenium chemoprevention in prostate cancer. Preliminary studies showed that physiological concentrations of a selenium metabolite inhibited the growth of both the androgen-responsive LNCaP and the androgen-nonresponsive PC-3 human prostate cancer cells. Analysis by flow cytometry indicated that selenium blocked cell cycle progression at multiple transition points after 24 hours and induced apoptosis after 48 hours. The Affymetrix GeneChip was used to profile the gene expression changes that might mediate these cellular events. Immediately before growth inhibition became evident in selenium-treated cells, a number of cyclins and CDKs were found to be depressed. These changes were accompanied by an increased expression of CDK inhibitors and other regulatory molecules that are known to reduce the activation of CDKs. Additionally, selenium also decreased the expression of genes involved in S phase transition, DNA synthesis and mitosis. Alterations in the transcript signal of many of these genes were confirmed at the protein level. Of particular interest is GADD153, a gene well documented to play an essential role in cell cycle control and apoptosis. The reasons for focusing on GADD153 are (a) it is one of the most highly modulated genes by selenium; (b) the induction occurs early and persists following selenium exposure; (c) as a transcription factor and a dimerization partner to other C/EBP and ATF family of proteins, it is an upstream target and is likely to modulate the transcription of many genes; and (d) the increase of GADD153 is observed in 4 different prostate cancer cell lines. The goal of this project is to investigate the role of GADD153 in contributing to the molecular effects of selenium. The research plan consists of 4 aims. Aim 1 is to determine the DNA binding activity of GADD153 in selenium-treated cells, and to identify the genes modulated directly by GADD153. Aim 2 is to characterize the dimerization partners of GADD153 following exposure to selenium. Aim 3 is to evaluate the changes in cellular responsiveness to selenium in the presence of antisense GADD153. Aim 4 is to study the transcriptional control of GADD153 by selenium. The proposed research is thus designed to examine systemically the impact of GADD153 induction as a result of selenium treatment.

描述（由申请人提供）：目前可获得有关前列腺癌硒化学预防的分子机制的信息。初步研究表明，硒代谢产物的生理浓度抑制了雄激素反应性LNCAP和雄激素 - 非反应PC-3人类前列腺癌细胞的生长。通过流式细胞仪分析表明，硒在24小时后在多个过渡点处阻断了细胞周期进程，并在48小时后诱导凋亡。 Affymetrix Genechip用于介绍可能介导这些细胞事件的基因表达变化。在经硒处理的细胞中显而易见的生长抑制作用之前，发现许多细胞周期蛋白和CDK被抑郁。这些变化伴随着CDK抑制剂和其他调节分子的表达增加，这些分子已知可减少CDK的激活。此外，硒还降低了与S相变，DNA合成和有丝分裂有关的基因的表达。在蛋白质水平上证实了许多这些基因的转录信号的改变。特别令人感兴趣的是GADD153，这是一个据可查的基因，可在细胞周期控制和凋亡中发挥重要作用。专注于GADD153的原因是（a）它是硒最高度调制的基因之一； （b）诱导早期发生，并在硒暴露后持续存在； （c）作为转录因子和其他C/EBP和ATF蛋白质家族的二聚化伴侣，它是上游靶标，很可能会调节许多基因的转录； （d）在4种不同的前列腺癌细胞系中观察到GADD153的增加。该项目的目的是研究GADD153在促进硒的分子作用方面的作用。研究计划由4个目标组成。目的1是确定硒处理细胞中GADD153的DNA结合活性，并确定直接由GADD153调节的基因。目的2是表征在暴露于硒后GADD153的二聚化伴侣。目的3是在存在反义GADD153的情况下评估细胞对硒的反应性的变化。 AIM 4是研究Selenium对GADD153的转录控制。因此，拟议的研究旨在从系统地检查GADD153诱导因硒治疗的影响。