Spectrum of transforming sequences detected by tumorigenicity assay in a large series of human neoplasms.

We here summarize the analysis of 126 DNA samples from patients with hematopoietic neoplasias and solid tumors and from various tumor cell lines that were screened in the tumorigenicity assay. Thirty-eight samples were able to induce tumors after transfection in NIH/3T3 cells and injection into nude mice. Southern-blot analysis with a panel of oncogene probes revealed human ras genes in the vast majority of cases (25 N-ras, 2 K-ras, 1 H-ras) but also activated FGF4, dbl, ret and mas genes respectively. DNA samples from the 6 remaining transfectants were cloned into EMBL-3 phages and screened with a human specific repetitive Alu probe. Direct hybridization of a transfectant cDNA library allowed cloning of the ufo oncogene. Application of the exon-trapping technique to alu-positive phage DNA from the other transfectants enabled us to isolate tre, cot, B-raf, p85beta/HUMORF8 and a novel oncogene.