Fig. 4

Cyclin D1 degradation by DKC-E70 is dependent on the activation of ERK1/2, p38 and GSK3β. a-c HCT116 cells were pretreated with PD98059 as an ERK1/2 inhibitor (a), SB203580 as a p38 inhibitor (b) or LiCl as a GSK3β inhibitor (c), and then co-treated with DKC-E70 (50 μg/ml) for 10 h. d HCT116 cells were treated with DKC-E70 (50 μg/ml) for the indicated times. Cell lysates were subjected to SDS-PAGE and the Western blot was performed using antibodies against cyclin D1, p-ERK1/2, total-ERK1/2, p-p38, total-p38, p-GSK3β or total-GSK3β. Actin was used as internal control for Western blot analysis. *P < 0.05 compared to cell without DKC-E70 treatment