REGULATION OF DIFFERENTIATION IN LUNG AND EPIDERMAL KERATINOCYTES

肺和表皮角质形成细胞分化的调节

• 批准号: 6106630
• 负责人: Anton M Jetten
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ENVIRONMENTAL HEALTH SCIENCES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6106630
• 关键词: DNA binding protein; biological signal transduction; cell cycle proteins; cell differentiation; cell growth regulation; cyclin dependent kinase; cyclins; enzyme activity; enzyme inhibitors; genetic transcription; guanine nucleotide binding protein; human tissue; interferon gamma; keratin; molecular cloning; oncoprotein p21; phosphorylation; protein glutamine gamma glutamyltransferase; regulatory gene; relaxin; retinoblastoma protein; retinoids; skin; tissue /cell culture

Summary of Work: Squamous differentiation is a multi-stage process that occurs in many tissues. The molecular link between control of growth arrest and differentiation is being studied. Insight into these mechanisms are important not only for understanding the control of normal differentiation but also the defects in diseases such as squamous metaplasia and cancer. Several different signaling pathways can induce squamous differentiation including those initiated by interferon gamma and phorbol esters. We demonstrated that keratinocytes become growth arrested at a specific point in the G1 of the cell cycle and is accompanied by an inhibition of Rb phosphorylation, decrease in cdk activity and induction of the cdk-inhibitors p27, p21 and p16. Although ectopic expression of p21 or p27 causes growth arrest, cells do not differentiate suggesting that additional signals are involved in terminal differentiation. Carcinoma cells are resistant to terminal differentia- tion and changes in growth-regulatory genes and induction of squamous- specific genes were not observed. We have identified and cloned several genes that are regulated during squamous differentiation, including transglutaminase type I (TGase I) and a membrane protein CL-20/EMP-1. To study the transcriptional regulation of these genes, we cloned the upstream regulatory region of TGase I and CL20, and determined by footprinting, deletion mutation and mobility shift assays DNA elements that CREB/AP-1-like sites are important in their transcriptional control. The 2.9kb upstream regulatory region of the TGase I gene to control the expression of a chloramphenicol acetyltransferase (CAT) reporter gene was also analyzed in vivo. These studies showed that the -2.9 kb promoter region contains all the information for the proper issue- and differentiation-specific expression of TGase I.

工作摘要：鳞状分化是 在许多组织中发生的多阶段过程。分子链接 在控制生长停滞和分化之间 研究。对这些机制的了解不仅很重要 了解对正常差异化的控制，也了解 诸如鳞状化生和癌症等疾病的缺陷。一些 不同的信号通路可以诱导鳞状分化 包括干扰素伽玛和佛波酯发起的那些。 我们证明了角质形成细胞在 细胞周期G1中的特定点，并伴随 抑制RB磷酸化，CDK活性的降低和 CDK抑制剂P27，P21和P16的诱导。虽然异位 p21或p27的表达会导致生长停滞，细胞不会 区分表明涉及其他信号 终端分化。癌细胞对末端具有抗性 差异和生长调节基因的变化和 未观察到鳞状基因的诱导。我们有 鉴定并克隆了几个在 鳞状分化，包括跨谷氨酰胺酶I型（TGase） i）和膜蛋白CL-20/EMP-1。研究 这些基因的转录调节，我们克隆了上游 TGase I和CL20的调节区域，并确定 足迹，删除突变和移动性转移测定DNA creb/ap-1状站点的元素在其中很重要 转录控制。 2.9kb上游监管区 TGase I基因控制氯霉素的表达 还分析了乙酰基转移酶（CAT）报告基因在体内分析。 这些研究表明-2.9 kb启动子区域包含所有 适当的问题和特定于分化的信息 Tgase I的表达。