Epigenetic Regulation by CHD7 in Colon Cancer

CHD7 在结肠癌中的表观遗传调控

• 批准号: 9296563
• 负责人: Marcos Estecio
• 金额: $ 20.88万
• 依托单位: UNIVERSITY OF TX MD ANDERSON CAN CTR
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-04-01 至 2019-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9296563
• 关键词: Antibodies; BRAF gene; Biology; Blood; Breast; CDH1 gene; CHD1 gene; CHD7 gene; Cancer cell line; Cell Line; Cells; ChIP-seq; Characteristics; Chromatin; Collection; Colon; Colon Carcinoma; Colonic Neoplasms; Colorectal; Colorectal Neoplasms; Complementary DNA; Complex; CpG Island Methylator Phenotype; DNA; DNA Binding; DNA Methylation; DNA-Binding Proteins; Data; Databases; Development; Disease; Down-Regulation; Drosophila genus; Drug Targeting; Encyclopedias; Enhancers; Enzymes; Epigenetic Process; Epithelial; Event; Family; Family member; Gene Activation; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Goals; Histones; Human; Hypermethylation; Immunoprecipitation; Large Intestine Carcinoma; Link; Lung Neoplasms; Lysine; Malignant Neoplasms; Maps; Mass Spectrum Analysis; Measures; Mediating; Modeling; Modernization; Molecular; Mutate; Mutation; Oncogenes; Organ; Outcome; Outcomes Research; PRC1 Protein; Pathway interactions; Plasmids; Play; Polycomb; Post-Translational Protein Processing; Reader; Recombinant Proteins; Regulation; Research; Role; Signal Pathway; Signal Transduction; Stomach Neoplasms; Subgroup; Tail; Testing; The Cancer Genome Atlas; Therapeutic Intervention; Tissues; Transfection; Tumor Biology; Tumor Suppressor Proteins; United States; Up-Regulation; Validation; Work; base; bisulfite sequencing; cancer type; chromatin remodeling; cohort; drug development; epigenetic regulation; epigenome; experimental study; gene repression; genome-wide analysis; helicase; improved; insight; interest; knock-down; member; methyl group; methylome; novel; overexpression; pancreatic neoplasm; programs; promoter; protein complex; response; small hairpin RNA; therapeutic target; therapy development; transcription factor; transcriptome; transcriptome sequencing; tumor; tumorigenesis

Abstract Chromodomain helicase DNA-binding (CHD) proteins are ATP-dependent chromatin remodeler enzymes that recognize methyl groups in lysines and participate in gene activation and repression, dependent on their cooperation with other chromatin reader complexes. The CHD family is composed of nine members (CDH1 to CHD9) grouped into three subfamilies based on the presence of additional functional domains. My group is interested in this family of enzymes because we found that CHD7 and CHD8 are mutated in 50% of CIMP1 colorectal carcinomas (CRCs). Although knowingly associated to developmental diseases, new studies have implicated these genes in other cancer types besides CRCs, including lung, gastric, and pancreatic tumors. Other CHD members are validated tumor suppressors, as examples CHD1 and CHD5, reinforcing the importance of the CHD family to tumor biology. In this study we will focus on the roles of CHD7 in epigenetic regulation with the goals of identifying directly regulated target genes and protein complexes that cooperate with this enzyme in normal and colon cancer. Colon cancer is third most deadly cancer type in the United States, and the premise of our research is that revealing facets of its epigenetic regulation will contribute positively to our understand of the disease and promote the development of therapies. We have collected preliminary data supporting that depletion of CHD7 results in increase in H3K27me3 levels, and deregulated the expression of known targets of the PRC1 and SNF2 complex. We will accomplish the goals of the project in two aims, using as models a collection of normal-derived, non-tumorigenic cell lines and colorectal carcinoma cell lines for which CHD7 down-regulation and up-regulation was manipulated by shRNAs and cDNA plasmids. In aim 1 we will evaluate changes in gene expression that occur in response of altered expression of CHD7. We will also measure the effects of altered expression of CHD7 on DNA methylation and selected histone tails posttranslational modifications. Histone marks associated with enhancers and promoters are of key interest. In aim 2, we will perform immunoprecipitation to validate and identify the interacting complexes that work along CHD7 in colon cells. Candidate partners are selected members of the PBAF and PRC1 complexes. CHD8 has been shown to act downstream to BRAF mutations to mediate DNA hypermethylation of CIMP genes, and we will also evaluate whether CHD7 partners with CHD8 and DNMT3A/B in wild type and mutated BRAF CRCs. Mass spectrometry will be used to account for unexpected interactions. The results of this project are expected to bring novel insights into how CHD7 in particular, and epigenetic alterations in general contribute to colorectal carcinomas, and identify novel pathways involved in CRC tumorigenesis that may represent opportunities for therapeutic intervention. In addition, they will also provide basic information on the role of CHD7 in gene regulation and its interacting complexes in colon cells.

摘要 染色体结构域解旋酶DNA结合（CHD）蛋白是ATP依赖性染色质重塑酶， 识别赖氨酸中的甲基，并参与基因激活和抑制，这取决于它们的 与其他染色质阅读器复合物合作。CHD家族由9个成员（CDH 1至CDH 2）组成。 CHD 9）根据额外功能结构域的存在分为三个亚家族。我们一行人都 我们对这个酶家族感兴趣，因为我们发现CHD 7和CHD 8在CIMP 1的50%中发生突变， 结直肠癌（CRC）。虽然明知与发育性疾病有关，但新的研究表明， 这些基因与CRC以外的其他癌症类型有关，包括肺、胃和胰腺肿瘤。 其他CHD成员是经验证的肿瘤抑制剂，例如CHD 1和CHD 5，增强了 CHD家族对肿瘤生物学的重要性。在本研究中，我们将重点关注CHD 7在表观遗传中的作用， 目的是鉴定直接调节的靶基因和蛋白质复合物， 在正常人和结肠癌患者中的作用。结肠癌是美国第三大致命癌症 我们研究的前提是，揭示其表观遗传调控的各个方面将有助于 对我们认识该病和促进治疗方法的发展具有积极意义。我们收集了 初步数据支持CHD 7的耗竭导致H3 K27 me 3水平的增加， PRC 1和SNF 2复合物已知靶点的表达。我们将在2010年完成项目目标。 两个目标，使用正常来源的非致瘤细胞系和结直肠癌细胞系的集合作为模型， 通过shRNA和cDNA质粒操纵CHD 7下调和上调的细胞系。 在目标1中，我们将评估响应CHD 7表达改变而发生的基因表达变化。 我们还将测量CHD 7表达改变对DNA甲基化和选择的组蛋白尾部的影响。 翻译后修饰与增强子和启动子相关的组蛋白标记是关键的兴趣。在 目标2，我们将进行免疫沉淀，以验证和确定相互作用的复合物，沿着 结肠细胞中的CHD 7。候选伴侣是PBAF和PRC 1复合物的选定成员。CHD 8具有 已被证明在BRAF突变下游起作用，介导CIMP基因的DNA超甲基化，我们 还将评估在野生型和突变的BRAF CRC中CHD 7是否与CHD 8和DNMT 3A/B配对。 质谱法将用于解释非预期相互作用。预计该项目的成果 特别是CHD 7，以及表观遗传学改变如何在结肠直肠癌中发挥作用， 癌症，并确定新的途径参与CRC肿瘤发生，可能代表的机会， 治疗干预此外，他们还将提供有关CHD 7在基因表达中作用的基本信息。 调节及其相互作用的复合物在结肠细胞。