ZINC FINGER GENES AND PANCREATIC CELL GROWTH

锌指基因与胰腺细胞生长

• 批准号: 2692610
• 负责人: RAUL A. URRUTIA
• 金额: $ 15.86万
• 依托单位: MAYO CLINIC ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-09-25 至 2002-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2692610
• 关键词: acinar cell; apoptosis; cell growth regulation; epithelium; genetic library; pancreas; protein localization; protein structure; tissue /cell culture; transcription factor

Our long-term goal is to define molecular mechanisms important for the regulation of cell proliferation and apoptosis in the exocrine pancreas which is a crucial step for better understanding normal morphogenesis and pancreatic cancer. Toward this end, we are studying the role of growth-factor inducible C2H2 zinc finger transcription factors in the regulation of these phenomena. Zinc finger proteins play a crucial role in organogenesis in several mammalian tissues, and mutations in some of these genes give rise to neoplastic transformation. However, their presence and function in the exocrine pancreas remain to be elucidated. The mechanistic experiments outlined in this proposal will test the central hypothesis that a novel TGFbeta-inducible zinc finger protein TIEG is a transcription factor involved in the regulation of apoptosis and/or the cell cycle in pancreatic cells. We have isolated a TIEG cDNA from a rat pancreas library and demonstrated that this gene is an early response target for TGFbeta in exocrine pancreatic cell populations. Interestingly, although its biochemical properties have not yet been determined, sequence analysis of the deduced TIEG protein reveals the presence of several motifs that are characteristic of transcription factors. Because TGFbeta induces both apoptosis and cell cycle arrest in pancreatic cell populations, TIEG is a good candidate to participate in these phenomena. Indeed, we have recently shown that the overexpression of TIEG in pancreatic cell populations induces apoptosis. Thus, in this proposal, we hypothesize that: 1) TIEG functions as a sequence-specific transcription factor, 2) the apoptotic effects of TIEG depend on the activity of this protein as a transcription factor, and 3) the overexpression of TIEG induces cell cycle arrest prior to apoptosis. These hypotheses will be addressed in the following specific aims: 1) Determine the nuclear localization and transcriptional regulatory activity of TIEG, 2) Determine the DNA binding sequence(s) for TIEG, and 3) Characterize the mechanisms involved in TIEG-induced apoptosis (transcriptional activity and cell cycle arrest). We propose to use state-of-the-art molecular techniques in combination with well- established functional assays to approach these aims. We are optimistic that the successful completion of this proposal will significantly advance our understanding on the role of zinc finger proteins in pancreatic cell physiology and begin to fill a gap in the existing knowledge in this underrepresented area of pancreatic research. Furthermore, this information will be crucial as a theoretical framework for future studies on the role of zinc finger transcription factors in pancreatic development and cancer.

我们的长期目标是定义对于 外分泌胰腺细胞增殖和凋亡的调节 这是更好地理解正常形态发生的关键一步 和胰腺癌。 为此，我们正在研究 生长因子诱导型 C2H2 锌指转录因子 对这些现象的监管。 锌指蛋白发挥着至关重要的作用 一些哺乳动物组织的器官发生以及某些组织的突变 这些基因引起肿瘤转化。 然而，他们的 外分泌胰腺的存在和功能仍有待阐明。 本提案中概述的机械实验将测试 中心假设是一种新型 TGFβ 诱导型锌指蛋白 TIEG是参与细胞凋亡调节的转录因子 和/或胰腺细胞中的细胞周期。 我们分离出了 TIEG cDNA 来自大鼠胰腺文库并证明该基因是早期 外分泌胰腺细胞群中 TGFbeta 的反应靶标。 有趣的是，尽管其生化特性尚未被证实 确定，推导的 TIEG 蛋白的序列分析揭示了 存在几个具有转录特征的基序 因素。 因为 TGFbeta 会诱导细胞凋亡和细胞周期停滞 在胰腺细胞群中，TIEG 是参与的良好候选者 在这些现象中。 事实上，我们最近已经表明， TIEG 在胰腺细胞群中的过度表达会诱导细胞凋亡。 因此，在本提案中，我们假设： 1) TIEG 的功能是 序列特异性转录因子，2) TIEG 的凋亡作用 取决于该蛋白质作为转录因子的活性，并且 3) TIEG 的过度表达诱导细胞周期停滞 细胞凋亡。 这些假设将在以下具体内容中得到解决 目标：1）确定核定位和转录 TIEG 的调节活性，2) 确定 DNA 结合序列 TIEG，以及 3) 描述 TIEG 诱导的机制 细胞凋亡（转录活性和细胞周期停滞）。 我们建议 使用最先进的分子技术与良好的相结合 建立功能测定来实现这些目标。 我们很乐观 该提案的成功完成将显着 增进我们对锌指蛋白在 胰腺细胞生理学并开始填补现有的空白 胰腺研究这一代表性不足的领域的知识。 此外，这些信息作为理论框架至关重要 为未来研究锌指转录因子在 胰腺发育和癌症。