REGULATION OF SQUAMOUS CELL DIFFERENTIATION

鳞状细胞分化的调节

• 批准号: 6162168
• 负责人: A 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/6162168
• 关键词: DNA binding protein; biological signal transduction; cell cycle proteins; cell differentiation; cell growth regulation; cyclins; enzyme activity; enzyme inhibitors; genetic transcription; guanine nucleotide binding protein; human tissue; interferon gamma; keratin; molecular cloning; 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 specific point in G1 of the cell cycle. This is accompanied by inhibition of Rb phos- phorylation, 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), cornifin a and b, relaxin and a membrane protein related to PMP22. To study the transcriptional regulation of these genes, we cloned the upstream regulatory region of TGase I, cornifin a and CL20. Footprinting, deletion mutation and mobility shift assays were used to identify important DNA elements. CREB- and AP-1-like sites are being further characterized. We analyzed the ability of a 2.9kb upstream regulatory region (of the TGase I gene) to control the expression of a chloramphenicol acetyltransferase (CAT) reporter gene in vivo and in vitro. Transgenic mice bearing the pTG(- 2.9)CAT construct exhibited the same pattern of tissue-specific expression of CAT as reported for TGase I.

工作总结：鳞状细胞分化是一个多阶段过程， 发生在许多组织中。生长控制之间的分子联系 逮捕和分化正在研究中。 洞察这些 机制不仅对于理解正常的控制很重要 分化以及鳞状细胞等疾病的缺陷 化生和癌症。多种不同的信号通路可以诱导 鳞状分化，包括干扰素γ引发的鳞状分化 和佛波酯。我们证明角质形成细胞会生长 停滞在细胞周期 G1 的特定点。这是伴随着 通过抑制 Rb 磷酸化、降低 cdk 活性和 诱导 cdk 抑制剂 p27、p21 和 p16。虽然是异位的 p21 或 p27 的表达导致生长停滞，细胞不分化 表明终端涉及附加信号 差异化。癌细胞对终末分化具有抵抗力 生长调节基因的变化和鳞状细胞的诱导 没有观察到特定基因。我们已经鉴定并克隆了几个 在鳞状细胞分化过程中受到调节的基因，包括 I 型转谷氨酰胺酶 (TGase I)、cornifin a 和 b、松弛素和 a 与 PMP22 相关的膜蛋白。 研究转录 为了对这些基因进行调控，我们克隆了这些基因的上游调控区 TGase I、cornifin a 和 CL20。足迹、缺失突变和 迁移率变动分析用于鉴定重要的 DNA 元件。 CREB ​​和 AP-1 样位点正在进一步表征。我们分析了 2.9kb 上游调控区（TGase I 基因）的能力 控制氯霉素乙酰转移酶 (CAT) 的表达 体内和体外报告基因。 携带 pTG(- 2.9)CAT构建体表现出相同的组织特异性模式 根据 TGase I 报告的 CAT 表达。