DEVELOPMENT OF EXPRESSION CLONING SYSTEM FOR ONCOGENE CDNAS

开发了一种高效的表达克隆系统来分离cDNA 这会改变细胞的形态。构建了一个cdna文库，该文库是从 小鼠肝细胞癌DNA诱导的转化子及其文库 用DNA转染NIH/3T3细胞。从几个人中的两个 获得转化灶，具有转化能力的相同质粒 都获救了。对该癌基因的cDNA克隆进行分析，命名为 表明该基因是由两个基因之间的重组事件产生的。 未知基因和B-raf原癌基因的小鼠同源物。这一基因 在两个初级转化子中分别检测到重排 由原始的肿瘤DNA诱导，表明重排 与人类不同，Hep1癌基因的产生是在人体内发生的 B-RAF癌基因是在DNA转染过程中体外产生的。

An efficient expression cloning system has been developed to isolate cDNAs which can change cell morphologies. A cDNA library was constructed from a transformant induced by mouse hepatocellular carcinoma DNA, and the library DNA was used to transfect NIH/3T3 cells. From two of the several transformed foci obtained, identical plasmids with transforming capability were rescued. Analysis of the cDNA clones for the oncogene, designated hep1, showed that the gene was created by recombination events between an unknown gene and mouse homologue of the B-raf proto-oncogene. This genetic rearrangement was detected in two primary transformants independently induced by the original tumor DNA, suggesting that the rearrangement generating the hep1 oncogene occurred somatically, in contrast to human B-raf oncogene which was created in vitro during DNA transfection.