Fig. 4

Functional effects of the modulation of CK1α, δ or ε on melanoma cell migration and invasion. a Real-time migration (upper panel) assays using the XCelligence DP analyzer. SKMEL19 Tet-On cells were induced to overexpress CK1- isoforms (red symbols) by doxycylcline pre-treatment for 48 h before seeding into the DP plates. Non-induced cells without doxycycline were used as reference controls (black symbols). For efficient overexpression of CK1α (red symbols) the adenoviral overexpression system was used 16 h before seeding the cells into the DP plates and effects were measured against lacZ control-transduced cells (black symbols). Shown are the cell indices of the measured impedance signals over 48 h. b SKMEL19 melanoma spheroid assay after CK1 overexpression (starting 24 h before collagen type I embedding). Spheroid spreading into the collagen matrix was microscopically monitored daily up to 4 days to estimate the invasive potential by referencing to day 0. Five spheroids were used for the calculations (Mean with SD; * p < 0.05). c Organotypic skin reconstructs with CK1 knockdown in SbCL2 melanoma cells. H&E staining is shown to reveal the invasive capacity into the dermal part after knockdown of CK1α. Matrigel coated invasion assays quantitatively show the invasive capacity of SbCl2 melanoma cells after knockdown of CK1 (lower right diagram)