An in vivo/in vitro experimental model system for the study of human osteosarcoma: canine osteosarcoma cells (COS31) which retain osteoblastic and metastatic properties in nude mice.

BACKGROUND: In this report we describe the establishment, characterization, and research utility of a cell line derived from a dog having a spontaneously occurring osteosarcoma.
MATERIALS AND METHODS: Tumor samples were collected from a dog with a naturally occurring osteosarcoma and processed for light microscopy, electron microscopy, immunocytochemistry, immunohistochemistry, karyology, and cell culture. Established cells from passage 31 (COS31; canine Qsteosarcoma cells from passage 31) were inoculated subcutaneously between the scapula and in the right abdominal side of athymic nude mice and evaluated similarly.
RESULTS: COS31 cells derived in cell culture and in nude mice had morphological and biochemical properties comparable in all respects to the original canine tumor specimen.
CONCLUSIONS: The ability of COS31 cells to produce tumors in nude mice (i.e. a small animal model) typical of canine osteosarcoma (i.e. a large animal model) with a similar pathological and biological behavior (e.g. alkaline phosphatase and osteocalcin positive immunostaining, osteoid production, rapid growth, and wide spread metastases) demonstrates the potential utility of COS31 cells as a in vitro and in vivo model system in the development of new strategies in the treatment of human osteosarcoma.