ESTABLISHMENT AND CHARACTERIZATION OF 2 CELL-LINES DERIVED FROM CANINE SPONTANEOUS OSTEOSARCOMA

Two new canine osteosarcoma cell lines were established. One (OOS) was established from a 10-year-old female maltese dog with mandibular ost eosarcoma and the other (HOS) from a 7-year-old male mongrel dog with scapular osteosarcoma. Histopathological types of OOS and HOS were mix ed and fibroblastic cell type, respectively. Transmission electron mic roscopic features of HOS revealed prominent rough endoplasmic reticulu m, suggesting higher malignancy comparing to OOS. Doubling time of OOS and HOS were 45.0 +/- 0.5 hr and 42.0 +/- 0.1 hr, respectively. Alkal ine phosphatase activities of OOS and HOS were quite low. Histological features of tumor tissues produced by transplantation of these cells into nude mice were identical to those of original osteosarcomas.