The role of KLF5 in GI epithelial homeostasis and disease

KLF5 在胃肠道上皮稳态和疾病中的作用

基本信息

批准号：
7888558
负责人：
JONATHAN P KATZ
金额：
$ 33.13万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2008
资助国家：
美国
起止时间：
2008-07-01 至 2012-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7888558
关键词：
Adhesions Anoikis Apoptosis Basal Cell Benign Binding Biological Biological Assay Breast Carcinogens Cells Colon Carcinoma Complex Cyclin D1 Data Disease Dysplasia Epidermal Growth Factor Epidermal Growth Factor Receptor Epithelial Epithelial Cell Proliferation Epithelial Cells Epithelium Esophageal Esophageal Diseases Esophageal Intraepithelial Neoplasia Esophageal Squamous Cell Esophagus Event Extinction (Psychology)Extracellular Matrix Foundations Future Gastroesophageal reflux disease Gastrointestinal tract structure Genetic Models for Cancer Genetic Transcription Growth Factor Receptors Homeostasis Human Immigration In Vitro Integrins Intestines Link Luciferases Malignant - descriptor Malignant Squamous Cell Neoplasm Malignant neoplasm of esophagus Malignant neoplasm of prostate Mediating Mesenchymal Modeling Molecular Mus Nucleic Acid Regulatory Sequences Pathway interactions Proliferating Property Prostate Proteins Receptor Signaling Regulation Reporter Reporting Research Research Design Role Signal Pathway Signal Transduction Small Interfering RNA Testing Transcriptional Regulation Transgenic Mice Transgenic Organisms Tumor Cell Invasion United States Yang Zinc Fingers adenoma angiogenesis cancer cell carcinogenesis chromatin immunoprecipitation gastrointestinal epithelium genetic regulatory protein in vivo in vivo Model insight integrin-linked kinase keratinocyte migration nitrosobenzylmethylamine notch protein novel overexpression promoter public health relevance transcription factor tumor tumor initiation tumorigenesis two-dimensional

项目摘要

DESCRIPTION (provided by applicant): Kr¿ppel-like factor 5 (KLF5; IKLF; BTEB2), a zinc-finger transcription factor with pro-proliferative properties in vitro, is expressed in proliferating cells of gastrointestinal tract epithelia, including the basal cells of the esophagus. The interplay of these cells with the extracellular matrix (ECM) is critical to their function, and we have shown that Klf5 regulates proliferation in esophageal epithelial cells through the epidermal growth factor receptor (EGFR). In novel preliminary data, we demonstrate that Klf5 increases migration via the integrin- linked kinase (ILK) in primary esophageal keratinocytes in culture. Given these findings, Klf5 is an excellent candidate to orchestrate esophageal epithelial cell proliferation and migration in vivo. However, despite significant evidence of a pro-proliferative role for KLF5 in non-transformed epithelial cells, KLF5 inhibits proliferation, promotes anoikis, and decreases invasion of esophageal squamous cancer cells. KLF5 is also deleted or down-regulated in human breast and prostate cancers, as well as intestinal adenomas from mice and humans. In epithelial cancer cells, KLF5 protein undergoes more rapid degradation than in non- transformed epithelial cells. These findings suggest that extinction of KLF5 function may be important for carcinogenesis. In fact, KLF5 has been suggested to have tumor suppressive functions in human breast, prostate, esophageal, and colon cancers. This dichotomous role for KLF5 is not unique, as divergent functions have been reported for other factors, such as TGF?, Notch, and KLF4. Here, we will investigate the role of KLF5 in normal and transformed esophagus by testing the following hypotheses: (1) KLF5 is a critical regulator of proliferation, differentiation, and migration in transit amplifying cells of the esophagus; and (2) loss of KLF5 is a key step in malignant transformation in the esophagus. We will test these hypotheses through the following interrelated Specific Aims. In Specific Aim 1, we will investigate the role of KLF5 in esophageal epithelial homeostasis by: (a) evaluating integrin, integrin-linked kinase (ILK), and epidermal growth factor receptor (EGFR) signaling in non-transformed keratinocytes with overexpression or suppression of KLF5; (b) studying the transcriptional regulation of EGFR and ILK by KLF5; (c) examining mice with transgenic expression of Klf5 in the esophagus. In Specific Aim 2, we will determine the function of KLF5 during esophageal tumorigenesis by: (a) examining the regulation of the integrin, ILK, and EGFR pathways by KLF5 in transformed esophageal squamous cells; and (b) evaluating dysplasia and tumor formation in mice with transgenic expression of Klf5 in esophagus which have been treated with the carcinogen NMBA or crossed with ED-L2/cyclin D1 transgenic mice, an established genetic cancer model. Overall, an understanding of the pathways regulated by KLF5 in esophageal epithelia will provide a framework to understand the molecular events underlying esophageal diseases, both benign and malignant. PUBLIC HEALTH RELEVANCE: Diseases of the esophagus, such as gastroesophageal reflux disease and esophageal cancer, are among the most common ailments in the United States and throughout the world, and these diseases result from dysregulation of normal epithelial homeostasis. Thus, an appreciation of the molecular mechanisms, including the specific factors and complex signaling arrays, which govern normal esophageal proliferation and differentiation is critical to the understanding of esophageal diseases, both benign and malignant. The research proposed in this application aims to elucidate these factors and signaling pathways through studies of the key regulatory protein KLF5.

描述（由申请人提供）：Kr¿ ppel 样因子 5（KLF5；IKLF；BTEB2）是一种在体外具有促增殖特性的锌指转录因子，在胃肠道上皮细胞（包括食道基底细胞）的增殖细胞中表达，这些细胞之间的相互作用。与细胞外基质 (ECM) 的相互作用对其功能至关重要，我们已经证明 Klf5 通过表皮调节食管上皮细胞的增殖。在新的初步数据中，我们证明 Klf5 通过整合素连接激酶 (ILK) 增加培养的原代食管角质形成细胞中的迁移，鉴于这些发现，Klf5 是协调食管上皮细胞增殖和生长的绝佳候选者。然而，尽管有大量证据表明 KLF5 在非转化上皮细胞中具有促增殖作用，但 KLF5 会抑制增殖，促进增殖。失巢凋亡，并减少食管鳞状癌细胞的侵袭，在人类乳腺癌和前列腺癌以及小鼠和人类的肠腺瘤中，KLF5 蛋白比非上皮癌细胞经历更快的降解。 - 转化的上皮细胞。这些发现表明 KLF5 功能的消失可能对致癌作用很重要。事实上，KLF5 已被认为在人类乳腺中具有肿瘤抑制功能。 KLF5 的这种二分作用并不是唯一的，因为其他因子（如 TGF、Notch 和 KLF4）也有不同的功能。在这里，我们将研究 KLF5 在正常和转化中的作用。通过测试以下假设来检测食管：(1) KLF5 是食管转运放大细胞增殖、分化和迁移的关键调节因子；(2) KLF5 的缺失是我们将通过以下相互关联的具体目标来检验这些假设。在具体目标 1 中，我们将通过以下方式研究 KLF5 在食管上皮稳态中的作用： (a) 评估整合素、整合素连接激酶（ ILK) 和 KLF5 过度表达或抑制的非转化角质形成细胞中的表皮生长因子受体 (EGFR) 信号转导； (b) 研究 KLF5 对 EGFR 和 ILK 的转录调节；(c) 检查食管中 Klf5 转基因表达的小鼠。在具体目标 2 中，我们将通过以下方式确定 KLF5 在食管肿瘤发生过程中的功能： KLF5 在转化的食管鳞状细胞中对整合素、ILK 和 EGFR 通路的调节；以及 (b) 评估小鼠的发育不良和肿瘤形成；经致癌物 NMBA 处理或与 ED-L2/cyclin D1 转基因小鼠杂交的食管中 Klf5 的转基因表达，这是一种已建立的遗传癌症模型，总体而言，了解食管上皮中 KLF5 调节的途径将为以下研究提供框架。了解食管疾病（良性和恶性）的分子事件：食管疾病，例如。胃食管反流病和食管癌是美国和全世界最常见的疾病，这些疾病是由正常上皮稳态失调引起的，因此，需要了解其分子机制，包括特定因素和复杂的信号传导阵列。，其控制正常的食管增殖和分化对于了解食管疾病（良性和恶性）至关重要。本申请中提出的研究旨在阐明这些疾病。通过对关键调节蛋白 KLF5 的研究来了解因子和信号通路。