Molecular Mechanisms of GSTP1 Reactivation by Green Tea Polyphenols

绿茶多酚重新激活 GSTP1 的分子机制

基本信息

批准号：
7262072
负责人：
SANJAY GUPTA
金额：
$ 28.32万
依托单位：
CASE WESTERN RESERVE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-07-01 至 2012-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7262072
关键词：
Aberrant DNA Methylation Acetylation Adenocarcinoma Adverse effects Affect Alleles Androgens Animal Model Atrophic Attention Behavior Benign Prostatic Hypertrophy Binding Binding Proteins Biological Biological Assay Breast Cancer Etiology Cancer cell line Carcinogens Case-Control Studies Catechin Cell Culture System Cell Line Cells Cessation of life Characteristics Chemoprevention Chemopreventive Agent Chinese People Chromatin Chromatin Structure Chromatin Structure Alteration Chromosomal Breaks Chromosomal Instability Clinical Clinical Trials Colon Colorectal Cancer Complex Consumption CpG Islands DMA-methyltransferase DNA DNA Methylation DNA Methyltransferase DNA Modification Methylases DNA Repair Gene DNA-Binding Proteins Daily Data Deacetylation Deoxycytidine Detoxification Process Development Diagnosis Diet Dietary Factors Disease Disruption Dose Drug Metabolic Detoxication Enzymes Epidemiologic Studies Epigallocatechin Gallate Epigenetic Process Epithelial Cells Event Exhibits Experimental Animal Model Family Fright Future GSTP1 gene Gene Expression Gene Silencing Genes Genetic Genetic Recombination Genetic Transcription Genome Genome Stability Genomics Genus Cola Glutathione S-Transferase Green tea Growth Heterogeneity Histone Acetylation Histone Deacetylase Inhibitor Histone H3 Histones Human Hypermethylation Implant Incidence Inflammatory Infusion procedures Invasive Japanese Population LNCaP Laboratory Study Lead Lesion Localized Disease Lung Malignant Epithelial Cell Malignant Neoplasms Malignant neoplasm of lung Malignant neoplasm of prostate Mediating Messenger RNA Methyl-CpG-Binding Protein 2 Methylation Modeling Modification Molecular Mus Mutate Mutation Nail plate Neoplasm Metastasis Nude Mice Nutritional Oncogenes Oral Pathway interactions Patients Pattern Phase Plasma Play Poison Population Predisposition Prevention Preventive Principal Investigator Process Promoter Regions Prostate Prostate carcinoma Prostatic Prostatic Intraepithelial Neoplasias Prostatic Neoplasms Protein Acetylation Protein Binding Domain Protein Family Proteins Recruitment Activity Refractory Regulation Repetitive Sequence Reporting Repression Research Personnel Retrotransposon Risk Role Series Source Specificity Specimen Staging Supplementation Tail Testing Time Toxic effect Transcriptional Activation Transcriptional Regulation Transgenic Organisms Tumor Suppressor Genes Tumor Tissue United States Up-Regulation base bisulfite bone cancer cell cancer risk cancer type carcinogenesis chromatin remodeling day demethylation disorder prevention drinking drinking water driving force enzyme activity gallocatechol gene repression glutathione S-transferase pi histone acetyltransferase human disease in vivo inhibitor/antagonist interest man member men novel nutrition programs promoter prostate cancer prevention protective effect protein H(3)protein expression research study transcription factor tumor tumor growth tumor progression tumorigenesis

Aberrant DNA Methylation Acetylation Adenocarcinoma Adverse effects Affect Alleles Androgens Animal Model Atrophic Attention Behavior Benign Prostatic Hypertrophy Binding Binding Proteins Biological Biological Assay Breast Cancer Etiology Cancer cell line Carcinogens Case-Control Studies Catechin Cell Culture System Cell Line Cells Cessation of life Characteristics Chemoprevention Chemopreventive Agent Chinese People Chromatin Chromatin Structure Chromatin Structure Alteration Chromosomal Breaks Chromosomal Instability Clinical Clinical Trials Colon Colorectal Cancer Complex Consumption CpG Islands DMA-methyltransferase DNA DNA Methylation DNA Methyltransferase DNA Modification Methylases DNA Repair Gene DNA-Binding Proteins Daily Data Deacetylation Deoxycytidine Detoxification Process Development Diagnosis Diet Dietary Factors Disease Disruption Dose Drug Metabolic Detoxication Enzymes Epidemiologic Studies Epigallocatechin Gallate Epigenetic Process Epithelial Cells Event Exhibits Experimental Animal Model Family Fright Future GSTP1 gene Gene Expression Gene Silencing Genes Genetic Genetic Recombination Genetic Transcription Genome Genome Stability Genomics Genus Cola Glutathione S-Transferase Green tea Growth Heterogeneity Histone Acetylation Histone Deacetylase Inhibitor Histone H3 Histones Human Hypermethylation Implant Incidence Inflammatory Infusion procedures Invasive Japanese Population LNCaP Laboratory Study Lead Lesion Localized Disease Lung Malignant Epithelial Cell Malignant Neoplasms Malignant neoplasm of lung Malignant neoplasm of prostate Mediating Messenger RNA Methyl-CpG-Binding Protein 2 Methylation Modeling Modification Molecular Mus Mutate Mutation Nail plate Neoplasm Metastasis Nude Mice Nutritional Oncogenes Oral Pathway interactions Patients Pattern Phase Plasma Play Poison Population Predisposition Prevention Preventive Principal Investigator Process Promoter Regions Prostate Prostate carcinoma Prostatic Prostatic Intraepithelial Neoplasias Prostatic Neoplasms Protein Acetylation Protein Binding Domain Protein Family Proteins Recruitment Activity Refractory Regulation Repetitive Sequence Reporting Repression Research Personnel Retrotransposon Risk Role Series Source Specificity Specimen Staging Supplementation Tail Testing Time Toxic effect Transcriptional Activation Transcriptional Regulation Transgenic Organisms Tumor Suppressor Genes Tumor Tissue United States Up-Regulation base bisulfite bone cancer cell cancer risk cancer type carcinogenesis chromatin remodeling day demethylation disorder prevention drinking drinking water driving force enzyme activity gallocatechol gene repression glutathione S-transferase pi histone acetyltransferase human disease in vivo inhibitor/antagonist interest man member men novel nutrition programs promoter prostate cancer prevention protective effect protein H(3)protein expression research study transcription factor tumor tumor growth tumor progression tumorigenesis

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项目摘要

DESCRIPTION (provided by applicant): Aberrant DNA methylation and chromatin remodeling are common epigenetic changes that play critical role in gene silencing; implicated in the development and progression of prostate cancer. One such alteration is silencing of the expression of glutathione S-transferase-pi (GSTP1), a critical enzyme of carcinogen defense, through methylation of deoxycytidine residue in CpG islands in the 5'-regulating region. Loss of GSTP1 function occurs in vast majority (>70%) of prostate tumors regardless of grade or stage and appears to be characteristic of human prostate tumorigenesis. Unlikely mutated genes; epigenetically silenced genes are intact and are attractive targets for agents that could 'wake up' these dormant genes. Reactivation of such genes could be accomplished by DNA methylation and/or histone deacetylase inhibitors however; clinical utility of these inhibitors has been limited due to severe side- effects and toxicity. In recent years, green tea and its major polyphenolic constituent, epigallocatechin-3-gallate (EGCG) has received much attention as a promising chemopreventive agent for prostate cancer. This notion is supported by recent case-control study (Int. J. Cancer 108:130-5, 2004); clinical trial (Cancer Res. 66:1234-40, 2006) and our observation demonstrating that oral consumption of green tea polyphenols (GTP) at human achievable dose results in significant inhibition of prostate carcinogenesis in transgenic adenocarcinoma of the mouse prostate (TRAMP) model that mimics human disease (Proc. Nail. Acad. Sci. USA 98:10350-5, 2001). Extensive laboratory studies in cell culture systems and in limited animal models have further demonstrated that GTP afford protective effects from diverse types of carcinogens and induce phase II enzyme activity that could lead to enhanced detoxification process. More recently GTP has been shown to inhibit the activity of DNA methyltransferase (Cancer Res. 63:7563-70, 2003). Importantly, if drinking green tea can restore or compensate the loss of GSTP1 activity in the prostate and can slow down the process of prostate carcinogenesis that may have relevance for prevention and/or treatment of this disease. In the proposed studies we further our understanding of how GTP and EGCG mediate reactivation of GSTP1 gene, silenced during prostate carcinogenesis. Through a series of exploration, we will specifically investigate whether these molecular mechanism(s) are mediated through epigenetic pathways related to i) demethylation and activation of aberrantly methylated GSTP1 gene, ii) modulation in binding and expression of transcriptional repressers: methyl CpG binding domain (MBD) proteins, DNA methyltransferases (DNMTs), and histone deacetylases (HDAC) to methylated DNA iii) alteration in activity and expression of histone acetyltransferases (HAT), iv) histone modification, and v) global hypomethylation patterns. These studies will be conducted in human prostate carcinoma LNCaP and MDA PCa 2b cells, which possess hypermethylated GSTP1 CpG island alleles, devoid of GSTP1 mRNA and protein expression. This will be further validated in athymic nude mouse orthotopically implanted with prostate carcinoma cells. Completion of this proposal will establish an important role of green tea polyphenols in modulating epigenetic events and will provide a rationale to conduct prevention-based clinical trial. With the 'proof of principle' more structurally-related non- toxic compounds could be developed in future for prevention of prostate cancer in humans.

描述（由申请人提供）：异常的DNA甲基化和染色质重塑是常见的表观遗传变化，在基因沉默中起着至关重要的作用。与前列腺癌的发展和发展有关。一种改变是通过5'-调节区域中CPG岛的脱氧胞苷残基的甲基化，通过甲基化脱氧胞苷残基的甲基化来使谷胱甘肽S-转移酶-PI（GSTP1）的表达沉默。 GSTP1功能的丧失发生在绝大多数（> 70％）的前列腺肿瘤中，而不论年级或阶段如何，并且似乎是人类前列腺肿瘤发生的特征。不太可能突变的基因；表观遗传沉默的基因是完整的，是可能“唤醒”这些休眠基因的药物的吸引力靶标。但是，可以通过DNA甲基化和/或组蛋白脱乙酰基酶抑制剂来重新激活此类基因。由于严重的副作用和毒性，这些抑制剂的临床实用性受到限制。近年来，绿茶及其主要的多酚组成部分，epigallocatechin-3-gallate（EGCG）已引起了人们对前列腺癌的一种有希望的化学预防剂的关注。该概念得到了最近的病例对照研究的支持（Int。J.Cancer 108：130-5，2004）。临床试验（CancerRes。66：1234-40，2006），我们的观察结果表明，人类可实现剂量的绿茶多酚（GTP）的口服消耗导致前列腺癌中的癌变显着抑制了小鼠前列腺（TRAMP）模型的转基因腺癌中的转基因腺癌（TRAMP）模型50. n. n. n. n. n. n.alail nesiail.niail。 2001）。在细胞培养系统和有限的动物模型中，广泛的实验室研究进一步证明，GTP可为各种类型的致癌物提供保护作用，并诱导II期酶活性，从而导致增强的排毒过程。最近，GTP已显示出抑制DNA甲基转移酶的活性（CancerRes。63：7563-70，2003）。重要的是，如果喝绿茶可以恢复或补偿前列腺中GSTP1活性的丧失，并且可以减慢前列腺癌变的过程，这可能与预防和/或治疗该疾病有关。在拟议的研究中，我们进一步了解GTP和EGCG如何介导GSTP1基因的重新激活，在前列腺致癌过程中沉默。通过一系列探索，我们将特别研究这些分子机制是否是通过与I）与异常甲基化GSTP1基因相关的表观遗传途径进行介导的（HDAC）至甲基化的DNA III）改变组蛋白乙酰转移酶（HAT），IV）组蛋白修饰和V）全局低甲基化模式的改变。这些研究将在人类前列腺癌LNCAP和MDA PCA 2B细胞中进行，这些细胞具有高甲基化的GSTP1 CpG岛等位基因，没有GSTP1 mRNA和蛋白质表达。这将在与前列腺癌细胞的原始小鼠原位植入的无胸腺裸鼠中进一步验证。该提案的完成将确定绿茶多酚在调节表观遗传事件中的重要作用，并将为进行基于预防的临床试验提供理由。通过“原理证明”，与结构相关的非毒性化合物可能会在未来预防人类的前列腺癌。