ErbB2 degradation induced by Pin1 inhibition can be rescued by proteasome inhibition. A. SKBR3 cells were transfected with control or Pin1 siRNA for 72 hours. 6 hours prior to protein lysis cells were treated with 100 μM ALLnL. B. Cell lysates were immunoprecipitated with anti-erbB2 antibodies and immunoblotting was done using antibodies against erbB2, Ubiquitin, Tubulin and Pin1. C. SKBR3, AU565 and BT474 were transfected with control or Pin1 siRNA for 72 hours. RNA was extracted using Trizol reagent and RT-PCR was performed using erbB2 and GAPDH specific primers.