Blocking casein kinase 1 epsilon function decreases E-cadherin expression and promotes cell migration. (a) Wild-type (WT) and mutant casein kinase 1 epsilon (CK1ε) were expressed in MCF7 cells together with the reporter encoding E-cadherin-promoter coupled to luciferase. Cells were lysed and the activity of luciferase was analyzed next day. (b) MCF7 cells were treated after seeding out by increasing concentrations of IC261 (2.5 μM, 5 μM and 10 μM) for 48 hours and the expression of E-cadherin was analyzed by western blotting. Empty arrowhead, unspecific band, which confirms equal protein loading. (c), (d) MCF7 cells were seeded out in the upper part of the Transwell migration chamber and were stimulated with indicated doses of (c) IC261 and (d) D4476. The number of migrating cells in the bottom chamber was counted next day, and is expressed as the migration index. Data represent mean ± standard deviation. *P < 0.05; one-way analysis of variance; (a), (c)Tukey post test, (d) Student's t test; n = 3. DMSO, dimethylsulfoxide.