ROLES OF PLEIOTROPHIN IN NORMAL AND ABNORMAL CELL GROWTH

多效素在正常和异常细胞生长中的作用

• 批准号: 2895222
• 负责人: Thomas F Deuel
• 金额: $ 30.89万
• 依托单位: BETH ISRAEL DEACONESS MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-06-10 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2895222
• 关键词: 3T3 cells; athymic mouse; binding proteins; breast neoplasms; cell growth regulation; cytokine; gene expression; gene interaction; genetically modified animals; heparin; mammary epithelium; molecular site; mouse mammary tumor virus; mutant; neoplasm /cancer genetics; neoplastic cell; neoplastic transformation; oncogenes; pathologic process; platelet derived growth factor; protein structure function; protooncogene; transforming growth factors; tumor promoters; tumor suppressor genes

Pleiotrophin (PTN) is a heparin-binding protein that functions as a weak mitogen with fibroblasts and brain capillary endothelial cells. It also induces process outgrowth and apparent differentiation with neuronal and glial progenitors. The ptn gene is a member of the platelet-derived growth factor (PDGF) induced early response cytokine genes and may mediate some of the normal functions of PDGF by autocrine or paracrine mechanisms. PTN also is transforming when its gene is overexpressed in NIH 3T3 cells. High levels of its expression have been found in mammary tumor cells and primary human breast tumors. Analysis of the functions of PTN in tumors thus may contribute to understanding both normal and abnormal cell growth. Furthermore, analysis of its ability to cooperate with other oncogenes offers a unique opportunity to study genetic pathways of tumorigenesis. Preliminary data are presented to establish that the PTN gene under control of the mouse mammary tumor virus (MMTV) promoter partially transforms mouse mammary epithelial cells. We plan to further study the potential of the ptn gene as a transforming gene in mouse mammary epithelial cells and as a transgene in mice. Its potential to cooperate with loss-of-function of tumor suppressor genes such as MMTV-p53 and gain-of-function of growth related genes such as MMTV-c-myc and MMTV-TGF- alpha to induce mammary tumors, and to enhance the aggressiveness of MMTV-c-neu induced mammary tumors in transgenic mice will be tested by cross-breeding MMTV-PTN mice with other MMTV-transgenic mice. It is also proposed to use mouse mammary epithelial cells to delineate functional (heparin binding, active site) domains of PTN that are required for its role in partial transformation by mutational analysis. The heparin binding mutants that are defined will be used to test the importance of binding of PTN to the extracellular matrix and/or cell surface for process outgrowth and in transformation. The active site mutants to be defined will be tested for loss of transforming potential in vitro, in the nude mouse, and for loss of ability to support process outgrowth of cells in cultures to determine if the same domaine mediates each of these activities. Appropriate functional mutants then will be expressed with MMTV in transgenic mice and tested alone and/or with cooperating genes by breeding to other MMTV transgenic mice. The results of this work will provide important new information on the functional roles of PTN, on its functional domains. It should direct strategies to alter the function of PTN in breast cancer and may advance understanding of the genetic basis of breast cancer in humans.

多效素 (PTN) 是一种肝素结合蛋白，其功能为弱 有丝分裂原与成纤维细胞和脑毛细血管内皮细胞。它还 诱导过程的生长和神经元的明显分化 神经胶质祖细胞。 ptn基因是血小板衍生基因的成员 生长因子 (PDGF) 诱导细胞因子基因的早期反应，并可能 通过自分泌或旁分泌介导 PDGF 的一些正常功能 机制。当 PTN 的基因在 NIH 3T3 细胞。在乳腺中发现其高水平表达 肿瘤细胞和原发性人类乳腺肿瘤。功能分析 因此，PTN 在肿瘤中的作用可能有助于理解正常和 细胞生长异常。进一步分析其合作能力 与其他癌基因的结合提供了研究遗传的独特机会 肿瘤发生的途径。 初步数据表明 PTN 基因在 小鼠乳腺肿瘤病毒（MMTV）启动子的部分控制 转化小鼠乳腺上皮细胞。我们计划进一步研究 ptn基因作为小鼠乳腺转化基因的潜力 上皮细胞并作为小鼠的转基因。其合作潜力 MMTV-p53 等肿瘤抑制基因功能丧失 生长相关基因如 MMTV-c-myc 和 MMTV-TGF- 的功能获得 alpha to induce mammary tumors, and to enhance the aggressiveness of MMTV-c-neu 在转基因小鼠中诱导的乳腺肿瘤将通过 MMTV-PTN 小鼠与其他 MMTV 转基因小鼠杂交。 还建议使用小鼠乳腺上皮细胞来描绘 PTN 的功能（肝素结合、活性位点）结构域 其在突变分析的部分转化中的作用是必需的。 定义的肝素结合突变体将用于测试 PTN 与细胞外基质和/或细胞结合的重要性 过程产物和转化的表面。活跃站点 将测试待定义的突变体是否丧失转化潜力 在体外，在裸鼠中，以及支持过程能力的丧失 培养物中细胞的生长以确定是否相同的结构域介导 这些活动中的每一项。然后将产生适当的功能突变体 在转基因小鼠中用 MMTV 表达并单独测试和/或与 通过与其他 MMTV 转基因小鼠繁殖来合作基因。结果 这项工作将提供有关功能的重要新信息 PTN 在其功能域中的角色。它应该指导战略 改变 PTN 在乳腺癌中的功能并可能促进对乳腺癌的了解 人类乳腺癌的遗传基础。