SIGNALING PATHWAYS OF TRANSFORMING ONCOGENES

许多转化癌蛋白定位于核外。 肿瘤的发生需要这些蛋白质传递它们的注意信号 到与稳定的基因变化相关的细胞核 执行转换。我们感兴趣的是确定核子 调解这些变化的因素并提出，至少在某些情况下 例如，它们由核原癌基因编码的产物组成 和即时早期反应基因(统称为 “核效应”基因)。这个家庭由以下成员组成： 它们本身是癌基因(c-myc、c-fos、c-jun)或由 生长刺激，但没有报道的致癌潜力(EGR-1/Zif268，NGF- 1B/Nur77)。我们将通过以下条件表达式测试我们的建议 核效应基因“反义”转录本转化NIH 3T3细胞的研究 由四种不同类型的癌基因(raf、src、ras和cis)决定。 糖皮质激素诱导的反义构建体将被转化为 对这些细胞和产生的集落进行形态检查 回归。将对单个克隆进行生物学特性检查 与软琼脂生长和致瘤等转化有关 在裸鼠身上很有潜力。V-K-ras转化NIH的初步结果 3T3细胞提示c-myc或NGF-1B/Nur77的缺失 诱导形态逆转，尽管只有c-myc反义克隆丢失 在软琼脂或低血清中生长的能力。除了肯定 拟议工作的可行性，这些结果表明存在 存在核效应基因的层次结构，每个基因控制着不同的 转化的表型的某些方面。我们希望利用这些细胞系 由这些研究产生，以检查其他通路的完整性 都被变形所扰乱。这可能会让我们确定 这些途径与ras转化是偶然或因果相关的。 路径。其他拟议的研究旨在进一步定性。 一种核外癌蛋白(Src)能够通过什么方式诱导 核效应基因JunB的表达。因此，该工作提出了 在此应用程序中具有相关性，原因如下：1)它将 确定核效应基因在介导转化中的作用 核外癌蛋白；2)它承诺展示一个层次结构 核效应基因；3)通过论证共同的要求 核效应基因，它有望揭示迄今未被赏识的 核外癌基因之间的关系；4)它将使我们能够 确定与其他信号通路转换的相关性；以及 5)它将确定潜在的治疗干预目标。

Many transforming oncoproteins are localized outside the nucleus. Tumorigenesis requires that these proteins transmit their advertent signals to the nucleus where the stable genetic changes associated with transformation are executed. We are interested in identifying the nuclear factors which mediate these changes and propose that, at least in some instances, they consist of the products encoded by nuclear proto-oncogenes and immediate early response genes (collectively referred to as the "nuclear effector" genes). This family consists of members which may themselves be oncogenes (c-myc, c-fos, c-jun) or which are induced by growth stimuli but have no reported oncogenic potential (egr-1/zif268, NGF- 1B/nur77). We will test our proposal by the conditional expression of the nuclear effector gene "antisense" transcripts in NIH 3T3 cell transformed by four different types of oncogenes (raf, src, ras, and cis). Glucocorticoid inducible antisense constructs will be transfected into these cells and the resultant colonies examined for morphological reversion. Individual clones will be examined for biological properties associated with transformation such as growth in soft agar and tumorigenic potential in nude mice. Preliminary results with v-K-ras-transformed NIH 3T3 cells indicate that the depletion of either c-myc or NGF-1B/nur77 induces morphological reversion although only c-myc antisense clones lose the ability to grow in soft agar or low serum. In addition to affirming the feasibility of the proposed work, these results suggest that there exists a hierarchy of nuclear effector genes, each controlling different aspects of the transformed phenotype. We expect to use the cell lines generated by these studies to examine the intactness of other pathways that are disrupted by transformation. This may allow us to determine whether these pathways are casually or causally linked to the ras transformation pathway. Additional proposed studies are aimed at further characterization of the means by which one extranuclear oncoprotein (src) is able to induce the expression of the nuclear effector gene junB. Thus, the work proposed in this application is relevant for the following reasons: 1) it will identify a role for nuclear effector genes in mediating transformation by extranuclear oncoproteins; 2) it promises to demonstrate a hierarchy of nuclear effector genes; 3) by demonstrating the requirement for common nuclear effector genes, it promises to reveal heretofore unappreciated relationships among extranuclear oncogenes; 4) it will allow us to determine the relevance to transformation of other signalling pathways; and 5) it will identify potential targets for therapeutic intervention.