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.

工作总结：鳞状细胞分化是一种 在许多组织中发生的多阶段过程。分子链 控制生长停滞和分化之间的联系 研究了深入了解这些机制不仅对 了解正常分化的控制， 鳞状上皮化生和癌症等疾病的缺陷。几 不同的信号通路可以诱导鳞状细胞分化 包括由干扰素γ和佛波醇酯引发的那些。 我们证明，角质形成细胞生长停滞在 在细胞周期的G1中的特定点，并伴随着 抑制Rb磷酸化，降低cdk活性， 诱导CDK抑制剂p27、p21和p16。虽然异位 p21或p27的表达引起生长停滞，细胞不 差异表明，额外的信号参与了 终末分化癌细胞对终末 分化和生长调节基因的变化， 未观察到鳞状细胞特异性基因的诱导。我们有 鉴定并克隆了几个基因， 鳞状分化，包括转氨酶I型（TGase I）和膜蛋白CL-20/EMP-1。研究 这些基因的转录调控，我们克隆了上游 TGase I和CL 20的调节区，并通过 足迹法、缺失突变和迁移率变动分析 CREB/AP-1样位点在其表达中起重要作用。 转录调控2.9kb的上游调控区 控制氯霉素表达的TGase I基因 乙酰转移酶（CAT）报告基因也进行了体内分析。 这些研究表明，-2.9kb启动子区含有所有的 针对特定问题和独特优势的信息 TGase I的表达。