HETEROGENEOUS PATTERN OF GENE-EXPRESSION IN CLONED CELL-LINES ESTABLISHED FROM A RAT TRANSPLANTABLE OSTEOSARCOMA LUNG METASTATIC NODULE

We have established three cloned cell lines (COS1NR, COS2NR and COS4NR ) from the lung metastatic nodule of a highly metastatic variant of ra t transplantable osteosarcoma, C-SLM. All three clones shared the same morphological characteristics and tumorigenicity, but their growth ra tes in vitro and metastatic ability in vivo differed from each other. Single-strand conformation polymorphism (SSCP) analysis revealed all t hree clones to have the same p53 gene mutation and parent C-SLM tumor. On the other hand, Northern blot analysis showed a different pattern of expression for the genes, c-fos, c-jun, c-Ha-ras, transin (rat stro melysin), bone Gla protein (osteocalsin) and nm23/NDP kinase. These re sults indicate the presence of a heterogeneous cell population in term s of the different pattern of gene expression in a lung metastatic nod ule of rat osteosarcoma and the present newly established cell lines w ill be useful for further investigation of the biological behavior of osteosarcomas. (C) 1998 Elsevier Science Ireland Ltd.