DNA Methylation and GSTP1 Gene Regulation in Gliomas

描述(申请人提供)：人类恶性胶质瘤是最常见的 难以治愈的人类肿瘤。因此，有一个持续的紧急情况 需要更好地了解潜在的分子机制 这些肿瘤的恶性生长、进展和治疗失败。其中 大脑和其他人类肿瘤中最常见的分子变化是 谷胱甘肽S转移酶P1基因的过表达。这 应用是基于对人类GSTP1基因的几个重要发现 我们实验室制造的神经胶质瘤。其中包括发现了 GSTP1基因座的等位基因多态性及GSTP1的研究 胶质瘤的基因表达具有高度的异质性，是一个很强的预后指标。 患者生存和对治疗反应的指标。我们在这方面的目标 应用是为了更好地理解调控的分子机制 GST-pi在恶性胶质瘤中的表达差异。我们将测试 假设GSTP1在胶质瘤中表达的异质性导致 由于GSTP1基因转录活性的差异 GSTP1基因5‘端CpGS甲基化结果差异 在改变染色质结构和改变转录因子结合到 GSTP1启动子，这最终解释了GSTP1的差异 胶质瘤之间的表达。利用原代标本和细胞系 人类恶性胶质瘤，我们将a)确定分化程度 GSTP1在恶性胶质瘤中的表达在转录水平上的调节 水平；b)确定CPGS的甲基化状态与 GSTP1基因5？区及其转录活性和表达 GSTP1基因，并检测不同的GSTP1等位基因是否 差异甲基化和表达以及GSTP1基因甲基化是否 状态与胶质瘤的耐药性有关；c)调查 GSTP15‘-区CPGS甲基化对转录的影响 与GSTP1启动子区域结合的因子和GSTP1启动子功能；d) 检查GSTP1基因甲基化是否与改变有关 GSTP1基因的组蛋白乙酰化/去乙酰化与染色质结构 以及这些因素是否共同决定了GSTP1在胶质瘤中的表达。这个 拟议的研究代表了一项重点明确的创新研究工作。这个 结果应该会产生与DNA甲基化相关的重要新信息 GSTP1基因在人脑胶质瘤中过度表达的机制 并将为努力在合理发展中更加有效作出贡献 这些肿瘤的药物和治疗策略。结果也应该领先于 为了更好地了解恶性过程，不仅是在胶质瘤中，而且 在许多其他人类癌症中也以GSTP1过度表达为特征。

DESCRIPTION (provided by applicant): Human malignant gliomas are among the most intractable of human tumors to therapy. There is, therefore, a continued urgent need for a better understanding of the molecular mechanisms underlying the malignant growth, progression and therapeutic failure in these tumors. Among the most common molecular alteration in brain and other human tumors is the over-expression of the glutathione S-transferase P1 (GSTP1) gene. This application is based on several important findings on the GSTP1 gene in human gliomas that have been made in our laboratory. These include the discovery of allelopolymorphism of the GSTP1 gene locus and the demonstration that GSTP1 gene expression in gliomas is highly heterogeneous and is a strong prognostic indicator of patient survival and response to therapy. Our goal in this application is to better understand the molecular mechanisms that regulate differential GST-pi expression among malignant gliomas. We will test the hypothesis that the heterogeneity in GSTP1 expression among gliomas results from differential transcriptional activity of the GSTP1 gene and that differences in methylation of CpGs in the 5'-region of the GSTP1 gene results in altered chromatin structure and altered transcription factor binding to the GSTP1 promoter, which ultimately accounts for the differences in GSTP1 expression between gliomas. Using both primary specimens and cell lines of human malignant gliomas, we will a) Determine be extent to which differential GSTP1 expression among malignant gliomas is regulated at the transcriptional level; b) Determine the relationship between methylation status of CpGs in the 5?-region of the GSTP1 gene and the transcriptional activity and expression of the GSTP1 gene in gliomas, and examine whether different GSTP1 alleles are differentially methylated and expressed, and whether GSTP1 gene methylation status is associated with drug resistance in gliomas; c) Investigate the effects of the methylation of CpGs in the GSTP1 5'-region on transcription factor binding to the GSTP1 promoter region and on GSTP1 promoter function; d) Examine whether methylation of the GSTP1 gene is associated with altered histone acetylation/deacetylation and chromatin structure at the GSTP1 gene locus, and whether these together determine GSTP1 expression in gliomas. The proposed studies represent a well-focused innovative research effort. The results should yield important new information on DNA methylation-related mechanisms involved in the over-expression of the GSTP1 gene in human gliomas and will contribute to efforts in the rational development of more effective agents and treatment strategies for these tumors. The results should also lead to a better understanding of the malignant process, not only in gliomas, but also in many other human cancer characterized be GSTP1 over-expression.