Cellular oncogenes in human teratocarcinoma cell lines.
We have analysed, by Northern blots, the expression of 14 cellular oncogenes in nine cell lines established from human teratocarcinomas. All lines expressed considerable amounts of p53, c-Ki-ras2, c-Ha-ras1, c-raf1, N-myc, and c-fos. Low level expression of c-myc was detected in some lines. Southern blot experiments revealed no amplification or rearrangement of the c-Ki-ras2, N-myc or c-fos genes. Using a rapid dot-blot screening procedure, based on a combination of in-vitro amplification of ras-specific sequences and oligonucleotide hybridization, we could detect no activation of Ha-ras or Ki-ras or any unexpressed N-ras sequences secondary to a point mutation at codons 12, 13, or 61.