Inhibitory Effects of Transforming Growth Factor-β1 Pretreatment on Experimental Pulmonary Metastasis of MCS-1 Chinese Hamster Mesenchymal Chondrosarcoma Cells

Recent studies have suggested that transforming growth factor(TGF)-β1 acts as a multifunctional regulator of cell growth, and also modifies tumor progression and metastasis. In the present study, we investigated the effects of TGF-β1 on the proliferation and experimental pulmonary metastasis of MCS-1. MCS-1 are undifferentiated type cloned tumor cells established from a mesenchymal chondrosarcoma which spontaneously occurred in the soft tissue of a female Chinese hamster. MCS-1 cells were pretreated with TGF-β1 (0, 0.05, 0.5, 2, 10 ng/ml) for 72 hours in a medium containing 1% fetal bovine serum, then tested for in vitro growth by the MTT method, in vivo growth by subcutaneous inoculation into athymic nude mice (1×106 cells/mouse) and experimental pulmonary metastasis by injection into the lateral teil vein of athymic nude mice (5×104 cells/mouse). TGF-β1 significantly inhibited in vitro growth of MCS-1, depending on its concentrations, and also experimental metastasis with maximal inhibition at 0.5 or 2 ng/ml treatment compared to untreated controls. TGF-β1, however, was ineffective for in vivo subcutaneous growth of MCS-1. These results indicated that TGF-β1 might be an inhibitor of metastasis of mesenchymal chondrosarcomas including other types of non-epitherial cartilage or bone formation tumors.