Expression of the transin, c-fos, and c-jun genes in rat transplantable osteosarcomas and malignant fibrous histiocytomas.

The expression of the transin, c-fos, and c-jun genes was assessed in transplantable osteosarcomas and malignant fibrous histiocytomas, as well as in pancreatic duct adenocarcinomas and hepatocellular carcinomas of rats and hamsters. Northern blot analysis revealed that both an undifferentiated osteosarcoma of spontaneous origin (SOS) and 4-hydroxyaminoquinoline 1-oxide (4-HAQO)-induced malignant fibrous histiocytomas with metastatic potential to the lung showed remarkably increased expression of transin mRNA transcripts. This was not the case for the other tumors. Interestingly, levels of transin mRNA were lower in lung metastatic lesions than in primary subcutaneous SOS tumors. The primary SOS and MFH expressed both c-fos and c-jun genes in conjunction with the transin gene, whereas the non-transin expressers, a 4-HAQO-induced osteosarcoma (COS) and the pancreatic duct adenocarcinomas, demonstrated one or the other, but not both. These results suggest a possible involvement of transin expression in the progression of spontaneous osteosarcomas and 4-HAQO-induced malignant fibrous histiocytomas in rats. Expression of the c-fos and c-jun genes may play a regulatory role in this process.