Expression of protooncogenes in murine osteosarcomas

Abstract

The expression of 7 protooncogenes (c‐sis, c‐abl, c‐mos, c‐bas, c‐Ki‐ras, c‐fos, c‐myc) was examined in transplants and established cell lines from spontaneous and radiation‐induced murine osteosarcomas. The transplant tumors were compared with different tissues, particularly skeletal tissue (sternum), and the osteosarcoma cell lines with fibroblast lines from the same mouse strains. C‐sis was expressed above the level of controls in 2 osteosarcomas (TV, Os5). Three osteosarcomas showed over‐expression of c‐abl (TVK, DOS, Os5), c‐bas (DOS, Os5 and V893) and c‐fos (TVK, DOS, Os5), and 4 osteosarcomas showed over‐expression of c‐Ki‐ras (TVK, DOS, Os5, Os16) and c‐myc (TVK, DOS, TV, Os5). C‐mos expression was not observed under the conditions used. One cell line (Os5) showed an altered transcript (1 kb transcript of c‐fos). Apart from the relatively frequent increase in expression of the c‐myc and c‐ras‐family, there was no indication that any particular protooncogene or combination of protooncogenes was associated with murine osteosarcomas.