Figure 2.

Growth properties of Rap1b-expressing Swiss 3T3 cells. (A) Growth curves of control (pL7-Hy, ▪) and Rap1b-expressing (pL-3-24, ◊; and pL-7-3-50, ▴) cells in serum-containing medium. Cells were plated on six-well dishes (50,000 per well, per triplicate) and counted daily after trypsinization. Results are expressed as average of triplicates (variation <5%). (B) Cell culture inserts (Falcon; 0.45-μm pore size) containing 50,000 cells of each cell line were placed on top of wells containing 50,000 pL7-Hy cells. Plates were treated as before and bottom wells (control cells) were counted daily to test for potential autocrine activity.