Fig. 4.

Cyclopamine does not affect IGF1- or IGF2-induced proliferation of GCPs. Purified GCPs were treated with SHH (400 ng/ml; n = 3), IGF1 (20 ng/ml) or IGF2 (40 ng/ml) alone or in combination with cyclopamine (5 μM). All growth factors alone enhance cell proliferation. Addition of cyclopamine significantly decreases cell proliferation for cells treated with SHH (p < 0.0001; n = 4), but it does not induce any significant decrease in the number of BrdU-positive cells when GCPs are treated with either IGF1 (p = 0.19; n = 4) or IGF2 (p = 0.15; n = 4). ∗ p < 0.05.