Figure 3.

Inhibition of SFKs, but not Jak2, reduces PRL-induced PRLR degradation. Serum-starved MCF-7 cells were pretreated with 10 μm SU6656 (A) or 25 μm AG490 (B) for 1 h and then treated with 50 μg/ml cycloheximide (CHX) with or without 4 nm PRL for 0, 30, 60, 120, or 240 min. Cell lysates were analyzed by immunoblotting with anti-PRLR. lPRLR levels were quantitated from three independent experiments, and normalized to vehicle-treated controls at time zero (mean ± sd). The asterisk indicates a significant difference between the CHX/SU6656/+PRL and CHX/+PRL treatment groups by Student’s t test (P ≤ 0.05).