MECHANISM OF GROWTH FACTOR-INDUCED TRANSFORMATION

对细胞转化机制的分析 转导特定基因(通过逆转录病毒感染、通过 肿瘤细胞DNA的转染法或正常基因的过度表达 细胞基因)表明，一个共同的特征是改变 在信号中特定成分的作用或调节中 介导细胞反应的信号转导通路 有丝分裂刺激。这个项目的长期目标是 应用是为了确定参与的分子机制 通过改变生长因子的调节来诱导转化- 介导的信号转导通路。一个核心因素是 有丝分裂反应涉及蛋白激酶C的激活 (PKC)，一种钙和磷脂依赖的激酶，已经被 被证明在增殖和增殖途径中被激活 差异化。因此，PKC调控的变化 活动可能会对增长控制产生戏剧性的影响。事实上, PKC活性和PKC调控基因的过度表达， 在成纤维细胞中被称为佛波宾，已经被证明可以诱导 转化的表型。初步证据表明， 佛手菜素的转化机制是通过一种 自分泌过程。这个应用程序概述了一个实验性的 一种确定PKC或phorbin基因是否发生改变的方法 可在特定类型的人类肿瘤中确定表达或 转化株系，以确定phorbin蛋白在 转化，以确定蛋白质的关键区域 这是诱导转变所必需的，并 确定该蛋白在PKC介导的细胞效应中的作用 差异化。回答这些问题将产生关键的 PKC介导的信号转导功能的研究进展 在细胞生长和分化中的途径以及关于 改变了细胞转化中这些途径的调节。 信号转导的机制研究将会有应用 在癌症诊断中，在治疗策略的设计中，也 在鉴定生长控制的分子机制方面 这在其他疾病过程中起到了作用。

Analysis of the mechanisms of cellular transformation by transduction of specific genes (by retroviral infection, by transfection of tumor cell DNA or by over-expression of normal cellular genes) indicate that a common feature is the alteration in the function or regulation of specific components in signal transduction pathways that mediate the response of cells to mitogenic stimulation. The long-term objectives of this application are to determine the molecular mechanisms involved in transformation induced by altered regulation of growth factor- mediated signal transduction pathways. A central factor in the mitogenic response involves the activation of protein kinase C (PKC), a calcium and phospholipid-dependent kinase that has been demonstrated to be activated in pathways of both proliferation and differentiation. Therefore, alterations in the regulation of PKC activity may have a dramatic effect on growth control. In fact, the over-expression of PKC activity and a PKC-regulated gene, termed phorbin, in fibroblasts has been demonstrated to induce a transformed phenotype. The preliminary evidence suggests that the mechanism of transformation by phorbin is mediated through an autocrine process. This application outlines an experimental approach to determine if alterations in PKC or phorbin gene expression can be identified in specific types of human tumors or transformed lines, to determine the role of the phorbin protein in transformation, to identify the critical regions of the protein that are required for the induction of transformation, and to determine the role of this protein in PKC-mediated effects on cell differentiation. Answering these questions will yield critical information about the function of PKC-mediated signal transduction pathways in cell growth and differentiation and about the role of altered regulation of these pathways in cellular transformation. Mechanistic studies of signal transduction will have applications in cancer diagnosis, in the design therapeutic strategies, and also in identification of the molecular mechanisms of growth control which that play a role in other disease processes.