Effect of EGF and neurotensin alone and in combination on DNA synthesis. Quiescent HCT116 (A), HT29 (B), and Panc-1 (C) cells were treated with 5 nM EGF, 1 μM neurotensin (NT), or a combination of both agents. [3 H]thymidine was added 12 h (HCT116) or 21 h after addition of agonists. The cells were harvested three hours after adding [3 H]thymidine and DNA synthesis was assessed as described in Methods. The results are presented as per cent of control values of three (HCT116) or six (HT29, Panc-1) independent experiments. Error bars indicate S.E.M. * Significantly different (p < 0.05) from control; # significantly different from control (p < 0.05), but not from neurotensin alone (A) or EGF alone (B, C).