Figure 4.

Effect of GHRH(1–29)NH₂ (1–10 μM) and GHRH antagonist JV-1–38 (1–10 μM), alone or in combination with GHRH(1–29)NH₂ at 1 μM concentration, on the proliferation of HT-29 and COLO 320DM colonic cancer cell lines in vitro. Data shown represent the mean ± SEM from three independent experiments performed in octuplicate. *, P < 0.05 and **, P < 0.001 vs. control; +, P < 0.05 and ++, P < 0.001 vs. 1 μM GHRH; ○, P < 0.05 vs. JV-1–38 alone at the corresponding concentration. Relative cell number in treated and control plates was determined by crystal violet staining (for HT-29) or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide assay (for COLO 320DM).