Fig. 5. GSK-3 is hyperactivated in PAR6N cells and GSK-3 inhibitors suppress PAR6N-induced apoptosis. (A) Immunoblot of phospho-GSK-3 (Ser9) (upper panel) and total GSK-3 (lower panel) from wild-type MDCK and PAR6N total SDS-lysates. (B) Wild-type MDCK and PAR6N cells grown in collagen for 4 days were then cultured in the presence of 20 µM SB216763, 50 µM LiCl or vehicle (DMSO) and immunostained with Myc (green), cleaved caspase-3 (red) and actin (white) at day 7. Values shown at the bottom of each panel indicate the percentage of cysts lacking cleaved caspase-3 staining (mean±s.d. of three experiments). Bar, 10 µm.