Social behaviour of cells in tissue culture. III. Mutual influence of sarcoma cells and fibroblasts.

Abstract 1. 1. Mutual influences on outgrowth in tissue culture of mouse sarcomata (S 37 and Crocker), mouse muscle and chick heart fibroblasts have been investigated by the method of confronted cultures. 2. 2. There are influences exerted before the outgrowths meet, causing cells to travel further towards an opposing explant than in other directions. In this respect the sarcoma cells are more affected by the fibroblasts than vice versa. 3. 3. After their outgrowths have met, the two types of fibroblast obstruct each other's movement, since one cell rarely moves over another's surface (contact inhibition). No obstruction of sarcoma cell movement by fibroblasts is detectable. Some obstruction of fibroblast movement by sarcoma outgrowth occurs. 4. 4. The hypotheses are suggested that contact inhibition occurs between fibroblasts of different origin; and that malignancy involves a loss or diminution of this response to contact.