EXPERIMENTAL PULMONARY METASTASIS OF CHIN ESE-HAMSTER MESENCHYMAL CHONDROSARCOMA CELL-LINES

Pulmonary metastases of chinese hamster mesenchymal chondrosarcoma cel l lines, MCS-1 (undifferentiated type) and MCS-8 (differentiated type) , were examined by intravenous transplantation into athymic nude mice. The incidence of pulmonary metastasis of MCS-1 was 100% and that of M CS-8 was 33% at the 23rd day after transfer. Mean number of metastatic nodules in the lung was 41 in the former and only 3 in the latter. Me an survival time of mice with MCS-1 injection (5 x 10(4) cells) was 27 days and that with MCS-8 (5 x 10(4) cells) was 48 days after transfer . At the 42nd day after transfer of MCS-8, however, the incidence of p ulmonary metastasis was 100%. These data suggest that the tumor growth rate in the metastatic lesion, as well as the affinity to the target organ, is very important for evaluation of experimental metastasis.