Establishment and characterization of a new cell line from a canine osteosarcoma

A new cell line has been established directly from a spontaneous osteosarcoma on the femur of a 1.5-year-old male mongrel dog and named POS. Doubling time of the cells was approximately 33 hr. Morphologically, spherical cells, fibroblast-like cells, large or small polygonal cells and multinucleated giant cells seemed to be the major component of this cell line. The transmission electron microscopic feature of most of the cells was abundant dilated rough endoplasmic reticulum. Alkaline phosphatase activity as one of the osteoblastic properties was high in this cell line. The tumor tissue produced by the inoculation of the cells into nude mice was histologically identical to the original osteosarcoma.