De novo methyltransferase function in chromatin & cancer

染色质中的从头甲基转移酶功能

基本信息

批准号：
7442300
负责人：
Keith D Robertson
金额：
$ 24.52万
依托单位：
UNIVERSITY OF FLORIDA
依托单位国家：
美国
项目类别：
财政年份：
2005
资助国家：
美国
起止时间：
2005-09-01 至 2009-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7442300
关键词：
Address Affect Biological Cell Line Cells Chromatin Chromatin Structure Chromosomal Instability Chromosome Condensation Chromosome Segregation Complex CpG Islands DNA DNA Binding DNA Methylation DNA Methyltransferase DNA Modification Methylases Data Development Embryonic Development Enzymes Epigenetic Process Event Functional disorder Gene Expression Gene Silencing Genes Genome Genome Stability Genomic Instability Genomics Goals Health Hereditary Disease Human Hypermethylation In Vitro Intervention Knock-out Knowledge Lead Link Malignant Neoplasms Mediating Methods Methylation Methyltransferase Microarray Analysis Mitotic Chromosome Monitor Mutate Mutation Normal Cell Pattern Property Proteins RNA Splicing Rare Diseases Recombinants Repetitive Sequence Research Personnel Role Somatic Cell Syndrome System Techniques Testing Tumor Suppressor Genes Variant Work base cancer cell cancer therapy cell growth chromatin remodeling condensin design in vitro Assay neoplastic cell novel prevent promoter tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Altered DNA methylation patterns, characterized by genome-wide hypomethylation in combination with CpG island hypermethylation, are one of the hallmarks of human tumor cells. Aberrant promoter /hypemethylation leads to silencing of tumor suppressor genes, while aberrant hypomethylation of repetitive sequences leads to genomic instability. The mechanisms that regulate de novo methylation and the de novo DNA methyltransferases DNMT3 A and DNMT3B remain almost totally unknown. Unlike DNMT3 A, DNMT3B is frequently over-expressed in tumor cells and paradoxically this can lead to both hypermethylation and hypomethylation events depending on the particular splice variant expressed. DNMT3B is also mutated in the rare disorder known as ICF syndrome, the only known genetic disease due to mutation of a DNA methyltransferase. The central hypothesis to be tested in this application is that DNMT3B is targeted to specific regions of the genome via interactions with chromatin-associated proteins and perturbing these interactions leads to abnormal methylation patterns and tumorigenesis. The three aims of this proposal are designed to test this hypothesis. In aim 1, the enzymatic and DNA binding properties of DNMT3B will be analyzed in vitro on naked DNA and chromatin substrates in the presence and absence of known DNMT3B interacting partners. Our second aim entails functionally characterizing a novel DNMT3B complex that we have identified which contains chromatin remodeling enzymes and condensin proteins. Lastly, we aim to identify and characterize DNMT3B target sequences using two powerful and complementary whole-genome-based microarray techniques. Addressing these questions will contribute to our fundamental understanding of how cellular DNA methylation patterns, particularly those mediated by DNMT3B, are established and maintained in cells. This is expected to positively affect human health by allowing for the development of novel therapies that will target aberrant epigenetic changes and provide additional new targets for pharmacologic intervention.

描述（由申请人提供）：DNA甲基化模式的改变，其特征是全基因组低甲基化与CPG岛高甲基化结合，是人类肿瘤细胞的标志之一。异常启动子 /脱甲基化导致肿瘤抑制基因的沉默，而重复序列的异常低甲基化会导致基因组不稳定。调节从头甲基化和从头DNA甲基转移酶DNMT3 A和DNMT3B的机制几乎完全未知。与DNMT3 A不同，DNMT3B在肿瘤细胞中经常过表达，矛盾的是，这可能会导致高甲基化和低甲基化事件，具体取决于表达的特定剪接变体。 DNMT3B也在称为ICF综合征的罕见疾病中突变，这是由于DNA甲基转移酶突变引起的唯一已知遗传疾病。在此应用中要检验的中心假设是，DNMT3B通过与染色质相关蛋白的相互作用而针对基因组的特定区域，并扰动这些相互作用会导致异常的甲基化模式和肿瘤发生。该提案的三个目标旨在检验该假设。在AIM 1中，在存在和不存在已知DNMT3B相互作用伴侣的情况下，将在裸DNA和染色质底物上分析DNMT3B的酶促和DNA结合特性。我们的第二个目标在功能上表征了我们已经确定的新型DNMT3B复合物，其中包含染色质重塑酶和冷凝蛋白。最后，我们旨在使用两种强大的基于全基因组的微阵列技术来识别和表征DNMT3B目标序列。解决这些问题将有助于我们对细胞DNA甲基化模式（尤其是由DNMT3B介导的模式）如何建立和维持在细胞中的基本理解。预计这将通过允许开发新的疗法来积极影响人类健康，这些疗法将针对异常表观遗传变化并为药理学干预提供其他新目标。