BIOLOGY AND PATHOLOGY OF A MODULATOR OF FGF

FGF 调节剂的生物学和病理学

• 批准号: 2712804
• 负责人: Anton Wellstein
• 金额: $ 22.26万
• 依托单位: GEORGETOWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-06-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2712804
• 关键词: 3T3 cells; MCF7 cell; angiogenesis; athymic mouse; binding proteins; bioassay; enzyme linked immunosorbent assay; fibroblast growth factor; gene targeting; hormone binding protein; messenger RNA; neoplastic growth; northern blottings; phenotype; protein structure function; receptor expression; restriction endonucleases; retinoids; ribozymes; squamous cell carcinoma; tetracyclines; transfection /expression vector; tumor promoters; vitamin receptor; western blottings

Acidic or basic fibroblast growth factors (FGF) are present at significant concentrations in most normal tissues in the adult, can stimulate angiogenesis and thus have the potential to play an important role during tumor growth and metastasis. However, both of these FGFs are immobilized in an inactive state on the extracellular matrix and it is only poorly understood how they are solubilized and activated to reach their extracellular receptors. One mechanism through which these growth factors can be mobilized is by binding to a secreted binding protein for FGF (BP) that was described by Wu et al in 1991. In recent work from our laboratory, we detected high levels of BP mRNA in majority of squamous cell cancer (SCC) samples from patients and in SCC cell lines in culture. On the other hand, we did not detect BP mRNA in normal adult human tissues or in normal adult rodent tissues as well as in a series of cultured cell lines that were not of squamous origin. In contrast with the lack of expression of BP in adult tissues, we found BP mRNA highly expressed in murine embryonic squamous epithelia of the lungs and skin during late gestation. In functional studies with non-tumorigenic cells (SW-13), we demonstrated that expression of BP can mobilize and activate bFGF leading to tumor growth and angiogenesis of the BP- transfected cells. Furthermore, in an SCC cell line expressing high levels of BP mRNA, reduction of BP expression using BP-targeted ribozymes reduced tumor growth and angiogenesis of xenografts of these cells in athymic nude mice. This suggests a potentially rate- limiting role of this protein for SCC tumor growth in vivo. In addition, we found that retinoids downregulate BP mRNA rapidly through a posttranscriptional mechanism. We propose the following experiments to study the role of BP in tumor growth as well as the mechanism(s) and therapeutic significance of its downregulation by retinoids: Under AIM 1, we will express BP in cell lines which have a low tumorigenic potential and are negative for BP and study phenotypic changes. The expression of BP will be under the control of a tetracycline- regulated promoter that allows to regulate transfected BP in vitro or in vivo by administration of tetracycline. Under AIM 2, we will use molecular targeting of BP mRNA with ribozymes to elucidate the contribution of BP to tumor growth of cell lines that express BP. Under AIM 3, we will study the mechanism(s) of retinoid regulation of BP with respect to receptor subtype and the retinoid- dependent target site in the BP mRNA. Furthermore, we will study to what extent downregulation of BP by retinoids contributes to the effect of these drugs on SCC tumors.

酸性或碱性成纤维细胞生长因子（FGF）存在于 成年人中大多数正常组织的显着浓度，可以 刺激血管生成，因此有可能发挥作用 在肿瘤生长和转移中的重要作用。 然而， 这两个FGF都以不活跃的状态固定在 细胞外矩阵，只有很差的了解它们是如何的 溶解并激活以达到其细胞外受体。 这些增长因素可以是一种机制 动员是通过与FGF的分泌结合蛋白结合（BP） Wu等人在1991年描述了这一点。 在我们的实验室最近的工作中，我们发现了高水平的BP 大多数鳞状细胞癌（SCC）样品中的mRNA 患者和培养中的SCC细胞系中。 另一方面，我们 未检测到正常成人人体组织中的BP mRNA或 正常的成年啮齿动物组织以及一系列培养的细胞 不是鳞状的线条。 与缺乏相反 BP在成人组织中的表达，我们发现BP mRNA高度 用鼠肺鳞状上皮表达 和妊娠晚期皮肤。 在非肿瘤细胞（SW-13）的功能研究中，我们 证明BP的表达可以动员和激活 BFGF导致BP-的肿瘤生长和血管生成 转染的细胞。 此外，在表达高的SCC细胞系中 BP mRNA的水平，使用BP靶向BP表达的降低 核酶减少了肿瘤的生长和异种移植的血管生成 这些细胞中的裸体小鼠。 这表明潜在的速率 - 该蛋白在体内的SCC肿瘤生长中的限制作用。 在 此外，我们发现类视网膜类动物迅速下调BP mRNA 通过转录后机制。 我们提出以下实验来研究BP在 肿瘤生长以及机制和治疗 维生素类似的下调其下调的意义：在AIM 1下，我们 将在具有低肿瘤势的细胞系中表达BP 并且对BP和研究表型变化是负的。 这 BP的表达将在四环素的控制之下 调节的启动子可以在体外调节转染的BP 或由四环素给药。 在AIM 2下，我们将 使用核酶对BP mRNA的分子靶向阐明 BP对表达细胞系的肿瘤生长的贡献 bp。 在AIM 3下，我们将研究类维生素的机制 BP相对于受体亚型和类维生素的调节 BP mRNA中的依赖性目标位点。 此外，我们会的 研究在多大程度上通过类维生素类似的BP下调有助于 这些药物对SCC肿瘤的影响。