SIGNALING PATHWAYS OF TRANSFORMING ONCOGENES

许多转化癌蛋白位于细胞核外。 肿瘤发生需要这些蛋白质传递它们的注意信号 到细胞核，在那里稳定的遗传变化与 转换被执行。 我们有兴趣确定核武器 这些因素介导了这些变化，并提出，至少在一些 例如，它们由核原癌基因编码的产物组成 和立即早期反应基因（统称为 "核效应物"基因）。 这个家庭的成员可能 它们本身是致癌基因（c-myc、c-fos、c-jun），或者由 生长刺激，但没有报道的致癌潜力（ZIF-1/zif268，NGF- 1B/nur77）。 我们将通过下面的条件表达式来测试我们的建议： NIH 3T3细胞核效应基因"反义"转录 由四种不同类型的癌基因（raf，src，ras和cis）。 将糖皮质激素诱导的反义构建体转染入 对这些细胞和所得集落进行形态学检查， 逆转 将检查单个克隆的生物学特性 与转化相关，如在软琼脂中生长和致瘤性 在裸鼠中的潜力。 v-K-ras转化NIH的初步结果 3T3细胞表明c-myc或NGF-1B/nur77的缺失 诱导形态逆转，尽管只有c-myc反义克隆丧失 在软琼脂或低血清中生长的能力。 除了确认 的可行性，这些结果表明， 存在一个核效应基因的层次结构，每个基因控制不同的 转化表型的方面。 我们希望用细胞系 这些研究产生的，以检查其他途径的完整性， 被转化所破坏。 这可以让我们确定 这些途径偶然地或因果地与ras转化相关 通路 其他拟议的研究旨在进一步表征 一种核癌蛋白（src）能够诱导 核效应基因junB的表达。 因此，建议的工作 在本申请中，由于以下原因而相关：1）它将 鉴定核效应基因在介导转化中的作用， 2）它承诺展示一个层次， 核效应基因; 3）通过证明共同的需要， 核效应基因，它有望揭示迄今未被重视的 （4）它将使我们能够 确定与其他信号传导途径转化的相关性;以及 5)它将确定治疗干预的潜在目标。

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.