Figure 4

PACAP and Forskolin Inhibit Proliferation in Primary Tumorsphere Cultures. [³H]-thymidine incorporation assays were performed in cultures treated with vehicle, increasing concentrations of PACAP, 5 μM forskolin, or 1 μM SANT-1 for 24 hours (A) or 48 hours (B). In each case, [³H]-thymidine was added for the last 18 hr of the experiment. Experiment was performed three times, with 3-4 samples for each treatment (** P < 0.01, *** P < 0.001).