TGF-BETA MODULATED GENE EXPRESSION

本申请中提出的实验旨在阐明 转化生长因子β 1（TGF β 1） 在软琼脂中刺激菌落形成。 TGF β的独特之处在于 考虑，因为它是唯一的补充时，添加到血清含有 持续启动和维持软琼脂菌落的培养基 增长 因为正常的锚定依赖性培养物生长的能力 在锚定独立的方式是最好的相关之一， 肿瘤发生，鉴定特定的调控基因可能 提供对初始事件（可能是限制速率的事件）的见解 控制肿瘤生长。 我们认为， 独特的基因程序，相对于单层生长所需的， 由TGF β 1启动软琼脂生长;转化可能 由这些基因的组成型或改变的表达引起。 一旦 这些基因已经被激活，正常的细胞机制需要 细胞分裂是有效的。 此外，抑制这些基因的表达 基因可以重建正常生长控制的许多方面。 我们将 通过以下方法检验这些假设：1）鉴定其表达被 在TGF β 1刺激的悬浮生长期间特异性调节; 2） 确定一组共同的基因是否相似地表达， 在各种转化的细胞系中所需的;和3）表征 细胞周期和生长因子调控特定蛋白的表达 由之前的目标中分离出来的克隆体编码 这些研究将 不仅增加了我们对导致 肿瘤发生性，但希望提出新的治疗靶点 干预

The experiments proposed in this application are designed to elucidate the mechanisms by which transforming growth factor beta1 (TGFbeta1) stimulates colony formation in soft agar. TGFbeta is unique in that regard since it is the only supplement when added to serum containing medium which consistently initiates and maintains soft agar colony growth. Since the ability of normal anchorage-dependent cultures to grow in an anchorage-independent manner is one of the best in correlates with tumorigenicity, the identification of specific regulatory genes might provide insights to the initial, and presumably rate limiting, events controlling neoplastic growth. It is our contention that expression of a unique program of genes, relative to that required for monolayer growth, is initiated by TGFbeta1 for soft agar growth; transformation might result from the constitutive or altered expression of these genes. Once these genes have been activated, the normal cellular machinery needed for cell division is operative. Moreover, inhibiting the expression of these genes may reestablish many aspects of normal growth control. We will test these hypotheses by 1) identifying unique cDNAs whose expression is specifically modulated during TGFbeta1-stimulated suspension growth; 2) determining whether a common set of genes are similarly expressed and required in various transformed cell lines; and 3) characterizing the cell cycle and growth factor regulated expression of specific proteins encoded by the clones isolated in the previous aims. These studies will not only increase our understanding of the events leading to tumorigenicity, but hopefully suggest new targets for therapeutic intervention.