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: 6678446
• 负责人: CLEMENT C IP
• 金额: $ 36.55万
• 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/6678446
• 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）：目前关于硒化学预防前列腺癌的分子机制的信息很少。初步研究表明，生理浓度的硒代谢物可抑制雄激素反应性 LNCaP 和雄激素非反应性 PC-3 人类前列腺癌细胞的生长。流式细胞术分析表明，硒在 24 小时后在多个转变点阻断细胞周期进程，并在 48 小时后诱导细胞凋亡。 Affymetrix GeneChip 用于分析可能介导这些细胞事件的基因表达变化。在硒处理的细胞中生长抑制变得明显之前，发现许多细胞周期蛋白和 CDK 受到抑制。这些变化伴随着 CDK 抑制剂和其他已知可减少 CDK 激活的调节分子表达的增加。此外，硒还降低了参与S相转变、DNA合成和有丝分裂的基因的表达。许多这些基因的转录信号的改变在蛋白质水平上得到证实。特别令人感兴趣的是 GADD153，该基因已被充分证明在细胞周期控制和细胞凋亡中发挥重要作用。关注 GADD153 的原因是 (a) 它是受硒调节程度最高的基因之一； (b) 诱导发生较早，并且在硒暴露后持续存在； (c) 作为转录因子和其他 C/EBP 和 ATF 蛋白家族的二聚化伴侣，它是上游靶标，可能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。该项目的目标是研究 GADD153 在促进硒的分子效应中的作用。该研究计划包括4个目标。目标 1 是测定硒处理细胞中 GADD153 的 DNA 结合活性，并鉴定 GADD153 直接调节的基因。目标 2 是表征接触硒后 GADD153 的二聚化伙伴。目标 3 是评估反义 GADD153 存在下细胞对硒反应性的变化。目标 4 是研究硒对 GADD153 的转录控制。因此，拟议的研究旨在系统地检查硒治疗对 GADD153 诱导的影响。