Figure 6.

V¹²Ras supplants the effect of ECM on proliferation. Parental GECs (Par) or GEC clones that express V¹²Ras were plated into culture wells that were coated with collagen or were uncoated (plastic) in serum-poor medium, with or without EGF (100 ng/ml). Cell number was determined 3 days after plating. Unlike parental GECs, V¹²Ras-transfected GEC clones were able to proliferate on plastic in the presence of EGF (lower panel). Except for clone R514, proliferation of V¹²Ras-transfected GECs did not occur in the absence of EGF (upper panel). Significant differences were present among groups (upper panel: P < 0.0001 ANOVA; *P < 0.0001 versus parental GECs on plastic and P = 0.05 versus R514, ⁺P < 0.005 versus parental GECs on plastic, mean ± SEM of four wells; lower panel: P < 0.0001 ANOVA; ⁺P < 0.0001, *P < 0.003, **P < 0.006, ⁺⁺P < 0.025 versus parental GECs on plastic, mean ± SEM of eight wells).