DETECTION AND ANALYSIS OF ONC GENES IN DEFINED MEDIA

某些病毒和肿瘤DNA诱导NIH/3 T3细胞灶的能力 已广泛用于识别和表征onc 基因. 然而，已经变得明显的是，焦点形成测定法是可行的。 仅能够检测潜在活性的小的子集， 肿瘤诱导基因，此外，病灶形成是一个相对 不确定的表型，几乎没有关于生化基础的信息 的转变。 为了扩大可检测的致癌基因的范围， 提供有关转化的生物化学基础的信息， 已开发出替代选择系统。 该试验涉及 选择细胞在无血清培养基中生长的能力， 胰岛素或血小板衍生生长因子，两者都是 需要支持NIH/353细胞的生长。 初步数据显示 生长因子的独立性是一种不同于失去联系的特性， 迄今为止测试的抑制和有限的一组onc基因显示出独特的 它们释放NIH/3 T3细胞生长因子的能力模式 要求. 将人肿瘤DNA转移到NIH/3 T3细胞中证明 不诱导病灶形成DNA确实赋予生长因子 独立 该提案中的实验利用该系统， 已知onc基因的表征，或检测和分离 来自人肿瘤和肿瘤细胞系的另外的onc基因，以及 分离部分逆转转化表型的基因， 肿瘤细胞系 （十）

The ability of some viral and tumor DNAs to induce foci of NIH/3T3 cells has been widely used for the identification and characterization of onc genes. It has become apparent, however, that the focus forming assay is capable of detecting only a small subset of the potentially active tumorinducing genes, and furthermore, that focus formation is a relatively undefined phenotype yielding little information about the biochemical basis of transformation. To expand the range of detectable oncogenes and to provide information about the biochemical basis of transformation, an alternative selective system has been developed. The assay involves selection for the ability of cells to grow in serum-free medium lacking either insulin or platelet-derived growth factor, both of which are required to support the growth of NIH/353 cells. Preliminary data indicate that growth factor independence is a property distinct from loss of contact inhibition and a limited set of onc genes tested to date show unique patterns in their ability to relieve NIH/3T3 cells of their growth-factor requirements. Transfer of human tumor DNA into NIH/3T3 cells demonstrated that DNAs which did not induce focus formation did confer growth factor independence. The experiments in the proposal utilize the system for the characterization of known onc genes, or the detection and isolation of additional onc genes from human tumors and tumor cell lines, and for the isolation of genes which partially revert the transformed phenotype of tumor cell lines. (X)