Characteristics of osteosarcoma cells in culture.

Osteosarcoma cells (BFO cell line) were successfully maintained in tissue culture for 3 years. BFO cells showed 100 per cent tumorigenicity by the isologous implantation, and almost the same histological features as the original BF osteosarcoma. BFO cells synthesize and secrete large quantities of alkaline phosphatase both in vitro (cell culture) and in vivo (tumor bearing mice). BFO cells showed a suppression in synthesizing the osteoinductive factor in vitro, but regained the capacity to synthesize it when implanted back into an isologous host. The cells showed rapid growth, a serum requirement, and no contact inhibition. Doubling time was 8.6 hours in a logarithmic growth phase. Cell cycle analyses by pulse labeling of 3H-thymidine was performed after synchronization of the cells by double treatment with an excess thymidine.