Epigenetic and clinical impact of SMARCB1 loss in cancer

SMARCB1 缺失对癌症的表观遗传学和临床影响

基本信息

批准号：
8495294
负责人：
Elizabeth J Perlman
金额：
$ 15.19万
依托单位：
LURIE CHILDREN'S HOSPITAL OF CHICAGO
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-07-01 至 2014-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8495294
关键词：
22q11 Address Agreement Attention Biological Assay Cell Line Cell Proliferation Cells ChIP-seq Child Children&apos s Oncology Group Chromatin Remodeling Factor Chromosomes Clinical Clinical Research Clinical Trials Complex Cyclin-Dependent Kinases DNA Methylation Development Disease EZH2 gene Embryo Employee Strikes Epigenetic Process Excision Failure Future Gene Expression Gene Expression Profile Gene Expression Profiling Genes Genetic Transcription Histones Human In Vitro Investigation Lead Longitudinal Studies Malignant - descriptor Malignant Neoplasms Measures Mediating Methylation Modeling Modification Mutation Pharmacologic Substance Play Polycomb Proteins RNA Interference RNA methylation Regulation Reporting Repression Rhabdoid Tumor Role SMARCB1 gene Staging Stem cells Survival Rate Testing Therapeutic Intervention Transcriptional Regulation Tumor Cell Line Xenograft procedure cytotoxic embryonic stem cell histone modification human embryonic stem cell in vivo infancy inhibitor/antagonist integrase interactor 1 knock-down member new therapeutic target novel therapeutics overexpression patient population pre-clinical sarcoma therapeutic target tumor

项目摘要

The SMARCB1 (hSNF5/INI-1) gene encodes the INI-1 protein, a component of the SWI/SNF chromatin remodeling complex. While the SWI/SNF complex is known to play an important role in transcriptional regulation, how it does so is largely unknown. Rhabdoid Tumors (RT) are rare, highly malignant sarcomas of infancy that demonstrate mutation and/or deletion of SMARCB1. We recently reported the global gene expression pattern of RT, and provided evidence that RTs arise within very early progenitor cells during a critical developmental window during which loss of SMARCB1 directly results in striking repression of differentiation and loss of cyclin dependent kinase inhibition. We provide additional evidence that these changes are largely mediated by changes in histone methylation. In this proposal we test our hypothesis that loss of SMARCB1 in early progenitor cells results in a global failure to release the polycomb group mediated repressive H3K27me3 on bivalent genes, resulting in arrested development and abnormal proliferation. Aim 1: To knock-down SMARCB1 within hESC and to measure changes in cell proliferation, differentiation, gene expression and DNA methylation compared with three RT cell lines. We will utilize RNA interference to knock-down SMARCB1 in two hESC and measure changes in proliferation, EZH2 expression, differentiation, and RNA and DNA methylation changes. These will be compared to those features in three RT cell lines. Global RNA and DNA methylation analysis in these studies will be compared with histone modifications in RT detected by global ChIP-SEQ being performed outside of this proposal. Aim 2: To investigate the direct and indirect impact of pharmacologic inhibition of EZH2 on cell proliferation in SMARCB1-deficient cells in vitro and in vivo. EZH2 represents the most important polycomb group protein in humans, and has been shown to be upregulated in a large number of tumors. It is therefore an attractive therapeutic target. We have established an agreement with GlaxoSmithKline for the study of a promising EZH2 inhibitor that is ready for preclinical development. We will perform in vitro cytotoxic assays on the three RT cell lines, and in vivo studies on xenografts created from the same cell lines. Both the in vitro and in vivo studies that are proposed are required prior to our ability to develop early clinical trials. Relevance: With an overall survival rate of 23%, new therapeutic options are urgently needed for RT. If our hypothesis is correct, it may result in novel therapeutic targets for RTs and the many other tumors that show histone modification or EZH2 overexpression. In addition, it will introduce a unique and important model of epigenetic control of both early embryonic differentiation and tumor development. Long-term, these studies will help to identify the underlying mechanisms by which histone modifications interact with other epigenetic mechanisms. This would then enable the investigation of epigenetic regulation more broadly in different patient populations, developmental stages, and diseases.

SMARCB1 (hSNF5/INI-1) 基因编码 INI-1 蛋白，该蛋白是 SWI/SNF 染色质的一个组成部分改造综合体。虽然已知 SWI/SNF 复合物在转录中发挥重要作用监管，它是如何做到这一点的很大程度上是未知的。横纹肌样瘤 (RT) 是罕见的高度恶性肉瘤表现出 SMARCB1 突变和/或缺失的婴儿期。我们最近报道了全球基因 RT 的表达模式，并提供了 RT 在非常早期的祖细胞中出现的证据关键的发育窗口，在此期间 SMARCB1 的缺失直接导致显着的抑制细胞周期蛋白依赖性激酶抑制的分化和丧失。我们提供了额外的证据表明这些变化主要是由组蛋白甲基化的变化介导的。在这个提案中，我们测试我们的假设早期祖细胞中 SMARCB1 的缺失导致整体无法释放多梳基团介导的抑制二价基因上的 H3K27me3，导致发育停滞和增殖异常。目标 1：敲低 hESC 内的 SMARCB1 并测量细胞增殖的变化，与三种 RT 细胞系相比，分化、基因表达和 DNA 甲基化。我们将利用 RNA 干扰敲低两个 hESC 中的 SMARCB1 并测量增殖、EZH2 的变化表达、分化以及 RNA 和 DNA 甲基化变化。这些将与那些功能进行比较在三个 RT 细胞系中。这些研究中的整体RNA和DNA甲基化分析将与组蛋白进行比较全球 ChIP-SEQ 检测到的 RT 修改是在本提案之外进行的。目的2：研究EZH2的药理学抑制对细胞的直接和间接影响 SMARCB1 缺陷细胞的体外和体内增殖。 EZH2代表最重要人类中的多梳族蛋白，并已被证明在大量肿瘤中表达上调。这是因此是一个有吸引力的治疗靶点。我们已与葛兰素史克 (GlaxoSmithKline) 达成协议研究一种有前景的 EZH2 抑制剂，已准备好进行临床前开发。我们将进行体外细胞毒性对三种 RT 细胞系进行测定，并对由相同细胞系产生的异种移植物进行体内研究。两者都在我们能够开展早期临床试验之前，需要进行所提议的体外和体内研究。相关性：RT 的总体生存率为 23%，迫切需要新的治疗选择。如果我们的假设是正确的，它可能会为 RT 和许多其他肿瘤带来新的治疗靶点组蛋白修饰或 EZH2 过度表达。此外，还将推出一个独特且重要的模型早期胚胎分化和肿瘤发育的表观遗传控制。从长远来看，这些研究将有助于确定组蛋白修饰与其他表观遗传相互作用的潜在机制机制。这将使表观遗传调控的研究能够在不同的领域进行更广泛的研究。患者群体、发育阶段和疾病。