Amplification of Both c‐myc and c‐raf‐1 Oncogenes in a Human Osteosarcoma

Fourteen human bone and soft part tumor tissues were screened by Southern blot hybridization using five oncogene probes (c‐myc, c‐K‐ras, c‐fos, c‐raf‐l, and N‐myc). Amplification of c‐myc was found in two osteosarcomas and one malignant fibrous histiocytoma. One of these osteosarcomas had amplified c‐raf‐1 gene. Rearrangement of the amplified gene was not observed. This is the first report of c‐raf‐1 amplification in human cancer tissues.