DETECTION AND ANALYSIS OF ONC GENES IN DEFINED MEDIA

某些病毒和肿瘤DNA对NIH/3T3细胞的诱导作用 已被广泛用于ONCE的鉴定和表征 基因。然而，很明显，焦点形成分析是 能够仅检测潜在活动的一小部分 致癌基因，而且，这种病灶的形成是一个相对 没有明确的表型，几乎没有关于生化基础的信息 转变的结果。扩大可检测到的癌基因的范围并 提供有关转化的生物化学基础的信息 已开发了替代选择系统。化验涉及到 无血清培养条件下细胞生长能力的筛选 无论是胰岛素还是血小板衍生生长因子，两者都是 以支持NIH/353细胞的生长。初步数据显示 生长因子独立性是一种与失去联系截然不同的特性 到目前为止，抑制和一组有限的癌基因测试显示出独特的 它们释放NIH/3T3细胞生长因子的能力模式 要求。人肿瘤DNA转移到NIH/3T3细胞的研究 没有诱导焦点形成的DNA确实提供了生长因子 独立。方案中的实验利用该系统进行 已知的癌基因的特征，或检测和分离 来自人类肿瘤和肿瘤细胞系的额外的癌基因，以及对于 部分逆转转化表型的基因分离 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)