Regulation of esophageal gene expression and function by KLF5 and p53

项目总结 食道衬里经常暴露在刺激物中，如酒精、香烟烟雾、热饮料、饮食 亚硝基化合物、胃十二指肠内容物的反流和食道的紊乱是显著的。 美国和世界各地的健康问题。例如，胃食道反流病(GERD) 导致美国每年有890万人次就诊，食道癌是第六大常见致癌原因 世界范围内的死亡。在食道上皮细胞中，关键的转录调节因子Kr？ppel-like factor5(KLF5) 促进正常的增殖和迁移，正如我们所展示的那样，我们最近发现了一种新的关系 在KLF5和P53之间，在食道上皮细胞中，P53充当KLF5的“分子开关”。P53 原代人食道角质形成细胞的突变将KLF5从促增殖转变为抗增殖， P21Waf1/Cip1和KLF5转录激活角质形成细胞瘤的作用 当p53突变而不是野生型p53时，抑制子NOTCH1。在其他初步数据中，我们 证明KLF5抑制食道角质形成细胞中的P53，并为全基因组研究提供证据 协调KLF5和P53的调控。我们的主要假设是KLF5和P53协调了广泛的 食道角质形成细胞的转录程序控制增殖、生长停滞、凋亡和 转型。为了验证这一假设，我们将追求以下相互关联的具体目标：1.我们 将描述KLF5调节P53水平和功能的机制~2。我们将定义 KLF5在p21Waf1/Cip1~3上的功能切换机制。我们将确定 KLF5在野生型和突变型p53~和4的背景下。我们将确定KLF5的功能后果 体内KLF5缺失和P53突变。这些互补的方法得到了我们强大的 初步数据，包括已发布和未发布的。此外，私家侦探是一名经验丰富的调查员， 精通Kr样因子、转录调控、胃肠道疾病动物模型， 和食道鳞状细胞生物学，最近相关的通讯作者出版物证明了这一点 癌症研究、PLoS One、细胞周期和肿瘤。此外，PI由一流的 研究团队，由专家合作者和特殊的资源、设施和 宾夕法尼亚大学和美国国立卫生研究院资助的分子研究中心的智力环境 消化系统疾病和肝脏疾病。总体而言，拟议的研究将提供对转录的关键见解 食道上皮细胞动态平衡的调节及其分子机制的研究 疾病，包括良性和恶性的。

PROJECT SUMMARY The esophageal lining is regularly exposed to irritants such as alcohol, cigarette smoke, hot beverages, dietary nitroso-compounds, and refluxate of gastro-duodenal contents, and disorders of the esophagus are significant health problems in the U.S. and throughout the world. For example, gastroesophageal reflux disease (GERD) leads to 8.9 million U.S. clinic visits annually, and esophageal cancer is the 6th most common cause of cancer death worldwide. In esophageal epithelia, the key transcriptional regulator Kr¿ppel-like factor 5 (KLF5) promotes normal proliferation and migration, as we have shown, and we recently identified a novel relationship between KLF5 and p53 in esophageal epithelial cells, whereby p53 acts as a "molecular switch" for KLF5. p53 mutation in primary human esophageal keratinocytes converts KLF5 from pro-proliferative to anti-proliferative, an effect mediated predominantly by p21Waf1/Cip1, and KLF5 transcriptionally activates the keratinocyte tumor suppressor NOTCH1 when p53 is mutant but not with wild-type p53. In additional Preliminary Data, we demonstrate that KLF5 suppresses p53 in esophageal keratinocytes and provide evidence for genome-wide coordinate regulation by KLF5 and p53. Our overarching hypothesis is that KLF5 and p53 orchestrate a broad transcriptional program in esophageal keratinocytes that controls proliferation, growth arrest, apoptosis, and transformation. To test this hypothesis, we will pursue the following interrelated Specific Aims: 1. We will delineate the mechanisms through which KLF5 regulates p53 levels and function~ 2. We will define the mechanism for KLF5 functional switching on p21Waf1/Cip1~ 3. We will identify common and exclusive targets of KLF5 in the context of wild-type and mutant p53~ and 4. We will determine the functional consequences of KLF5 loss and p53 mutation in vivo. These complementary approaches are supported by our robust Preliminary Data, both published and unpublished. Moreover, the PI is an experienced investigator who is an expert in the Kr¿ppel-like factors (KLFs), transcriptional regulation, animal models of gastrointestinal diseases, and esophageal squamous cell biology, as demonstrated by recent, relevant corresponding-author publications in Cancer Research, PLoS One, Cell Cycle, and Neoplasia. In addition, the PI is supported by a superb research team, complemented by expert collaborators, and by the exceptional resources, facilities, and intellectual environment of the University of Pennsylvania and the NIH-funded Center for Molecular Studies in Digestive and Liver Diseases. Overall, the proposed studies will provide key insights into the transcriptional regulation of esophageal epithelial homeostasis and the molecular pathways that underlie esophageal diseases, both benign and malignant.