Epigenetics and Infection-induced EMT of Colonic Crypts - Target for Chemoprevention

表观遗传学和感染诱导的结肠隐窝 EMT——化学预防的目标

• 批准号: 8828347
• 负责人: Shahid Umar
• 金额: $ 39.3万
• 依托单位: UNIVERSITY OF KANSAS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-01-05 至 2019-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8828347
• 关键词: Adenocarcinoma; Antibodies; ApcMin/+ mice; Area; Bacteria; Bacterial Infections; Biological Assay; Butyrates; Carcinoma; Cell Separation; Cells; Chemoprevention; Citrobacter rodentium; Colitis; Colon; Colon Carcinoma; Data; Diagnostic; Diet; Dietary Intervention; Disease; Distant Metastasis; E-Cadherin; Embryonic Development; Epigenetic Process; Epithelial; Epithelial Cells; Escherichia coli EHEC; Etiology; Event; Exhibits; Fibronectins; Galactosidase; Gene Expression Profile; Genetic Transcription; Histone Deacetylation; Human; Hyperplasia; Immunologic Markers; In Vitro; Individual; Infection; Inflammation; Injury; LTB4R gene; Lamina Propria; Lesion; Link; MEKs; Malignant - descriptor; Malignant Neoplasms; Mediating; Mesenchymal; Modeling; Mus; NF-kappa B; Neoplasm Metastasis; Parasites; Pathway interactions; Phase; Phenotype; Polyps; Process; Property; Recurrence; Role; Signal Pathway; Signal Transduction; Smooth Muscle Actin Staining Method; Specificity; Staining method; Stains; Stem cells; Stromal Cells; Tamoxifen; Testing; Therapeutic; Tissues; Up-Regulation; Vimentin; Virulence Factors; Virus; adenoma; base; cancer cell; cancer stem cell; carcinogenesis; chromatin immunoprecipitation; chromatin remodeling; colonic crypt; crypt cell; design; differential expression; enteric pathogen; epigenetic regulation; epithelial to mesenchymal transition; histone methylation; histone modification; human EZH2 protein; inhibitor/antagonist; metastatic process; microbial; microorganism; mutant; neoplastic cell; notch protein; novel; pathogen; prevent; programs; promoter; prophylactic; public health relevance; response; stem; stemness; tributyrin; tumor; tumor initiation; tumor progression; tumorigenesis

DESCRIPTION (provided by applicant): The trans-differentiation of epithelial cells into mesenchymal cells, a process known as epithelial-mesenchymal transition (EMT) occurs throughout embryonic development and is recapitulated during epithelial tissue injury and in carcinoma progression. This plasticity is enabled by underlying shifts in epigenetic regulation. Little is known however, regarding our understanding of how these pathways coordinately suppress the epithelial phenotype and induce a mesenchymal program that generates cells with properties of stem cells and whether the acquisition of EMT phenotype in genetically predisposed individuals could be an early event triggered by enteric pathogens. Citrobacter rodentium (CR) causes infectious colitis and shares a remarkable functional similarity to enteropathogenic (EPEC) and enterohemorrhagic (EHEC) E. coli in promoting attaching and effacing (A/E) lesion formation as a major mechanism of tissue targeting and infection. We have shown previously that functional cross-talks between Wnt/b-catenin, Notch and NF-kB pathways, regulate crypt hyperplasia and/or tumorigenesis in response to CR infection while inflammation and/or colitis is regulated by the MEK/ERK and NF-kB pathways. We have also discovered differential expression of stem cell markers Dclk1 and Lgr5 during progression (days 6-12) and regression (days 20-34) phases of crypt hyperplasia. CR- infected crypt epithelial cells and adenomas stain positive for vimentin, fibronectin and Dclk1 but negative for E-cadherin thereby exhibiting an EMT-like phenomenon. These events seem to be epigenetically regulated as isolated crypts exhibit elevated levels of EZH2 (Enhancer of Zeste Homolog-2) that transcriptionally represses E-cadherin and WIF1 (Wnt Inhibitory Factor 1) expression via histone methylation and deacetylation. Elevated levels of EZH2 and b-catenin with concomitant decrease in WIF1 expression in the adenomas of CR-infected ApcMin/+ mice also parallel changes recorded in BLT1-/-ApcMin/+ mice, a spontaneous model of colon cancer, in AOM/DSS model and in human adenocarcinomas. Finally, orally administered Tributyrin (TBT) blocks EZH2, upregulates WIF1 and inhibits crypt hyperplasia. Based on these findings, we hypothesize that CR infection- induced epigenetic signaling via EZH2 in stem and/or progenitor cells of genetically susceptible mice will promote EMT of colonic crypts and that TBT/butyrate will mitigate epigenetically-linked EMT and/or metastatic process by upregulating WIF1. We propose three specific aims to test this hypothesis. In Aim 1, we will investigate whether alteration in EZH2/WIF1 axis within the stem cells in response to bacterial infection precedes or accompanies EMT, local invasion or metastasis. Aim 2 will attempt to establish specificity of the epigenetic and EMT changes in the colon in response to CR infection and, Aim 3 will examine if TBT blocks stem cell-driven and epigenetically regulated process of EMT and/or tumor spread. The new found role for TBT as an inhibitor of EZH2 is expected to eventually pave the way for developing TBT as a therapy to eliminate cancer-initiating cells thereby helping to prevent tumor recurrence or distant metastasis.

描述（由申请人提供）：上皮细胞向间充质细胞的转分化，即称为上皮-间质转化（EMT）的过程，发生在整个胚胎发育过程中，并在上皮组织损伤和癌症进展过程中重演。这种可塑性是通过表观遗传调控的潜在变化实现的。然而，我们对这些途径如何协调抑制上皮表型并诱导间充质程序产生具有干细胞特性的细胞以及在遗传易感个体中获得 EMT 表型是否可能是由肠道病原体触发的早期事件知之甚少。 。啮齿类柠檬酸杆菌 (CR) 会引起传染性结肠炎，并且与肠致病性 (EPEC) 和肠出血性 (EHEC) 大肠杆菌具有显着的功能相似性，可促进附着和消除 (A/E) 病变形成，作为组织靶向和感染的主要机制。我们之前已经表明，Wnt/b-连环蛋白、Notch 和 NF-kB 通路之间的功能性串扰可响应 CR 感染调节隐窝增生和/或肿瘤发生，而炎症和/或结肠炎则由 MEK/ERK 和 NF 调节-kB 途径。我们还发现干细胞标记物 Dclk1 和 Lgr5 在隐窝增生的进展（第 6-12 天）和消退（第 20-34 天）阶段存在差异表达。 CR感染的隐窝上皮细胞和腺瘤对波形蛋白、纤连蛋白和Dclk1染色呈阳性，但对E-钙粘蛋白呈阴性，从而表现出类似EMT的现象。这些事件似乎受到表观遗传调控，因为分离的隐窝表现出 EZH2（Zeste Homolog-2 增强子）水平升高，通过组蛋白甲基化和脱乙酰化转录抑制 E-钙粘蛋白和 WIF1（Wnt 抑制因子 1）表达。 CR 感染的 ApcMin/+ 小鼠腺瘤中 EZH2 和 β-连环蛋白水平升高，同时 WIF1 表达降低，这也与 AOM/DSS 中 BLT1-/-ApcMin/+ 小鼠（一种自发性结肠癌模型）中记录的平行变化有关模型和人类腺癌中。最后，口服三丁酸甘油酯 (TBT) 可阻断 EZH2、上调 WIF1 并抑制隐窝增生。基于这些发现，我们假设 CR 感染在遗传易感小鼠的干细胞和/或祖细胞中通过 EZH2 诱导表观遗传信号传导，将促进结肠隐窝的 EMT，而 TBT/丁酸盐将通过以下方式减轻表观遗传相关的 EMT 和/或转移过程：上调 WIF1。我们提出了三个具体目标来检验这一假设。在目标 1 中，我们将研究干细胞内 EZH2/WIF1 轴因细菌感染而发生的改变是否先于或伴随 EMT、局部侵袭或转移。目标 2 将尝试确定结肠中对 CR 感染的表观遗传和 EMT 变化的特异性，目标 3 将检查 TBT 是否阻断干细胞驱动和表观遗传调节的 EMT 和/或肿瘤扩散过程。新发现的 TBT 作为 EZH2 抑制剂的作用有望最终为开发 TBT 作为消除癌症起始细胞的疗法铺平道路，从而有助于预防肿瘤复发或远处转移。