Rescue of epithelial sheet migration by expression of EpCAM-YFP or point mutants of EpCAM-YFP in MDCK cells depleted of EpCAM.

(A) Phospho-ERK levels in EpCAM-depleted Esh2 cells (Esh) and Esh2-derived cell lines were analyzed as in Fig 5A and 5B. Error bars: S.E.M. of six independent samples for each cell line; p values derived from unpaired Student’s t test: *** p = 0.0004 for Esh+EY to Esh and *** p = 0.0001 for Esh+EEY to Esh. Phospho-ERK levels in Esh+EIY were not significantly reduced from the levels in the parental Esh line. (B) Phase images of indicated cell lines at 0 hrs (top row), and 6 hrs migration (middle row). The bottom row shows an overlay of “6 hrs” images onto “0 hrs” images. Scale bars: 100 μm. The graph in (B) shows quantification of average change of area/image after 6 hrs migration. Error bars: S.E.M. for five (Esh+EIY) to six experiments (Esh+EY, Esh+EEY) as shown in the phase images. Esh+EY and Esh+EEY migrate significantly slower than parental Esh cell sheets. The migration of Esh+EIY is not significantly different from Esh cell sheets. Stars correspond to p values derived from unpaired Student’s t test: * p = 0.0175 for Esh+EY and **p = 0.0063 Esh+EEY compared to Esh.