Immunofluorescence studies were performed as described previously (Ma et al, 2010 (link)), with an anti-E-cadherin primary antibody (#3195, 1 : 200 dilution; Cell Signaling Technology, Danvers, MA, USA) and an Alexa Fluor-647-conjugated anti-rabbit secondary antibody (#4414, 1 : 1000 dilution; Cell Signaling Technology). For staining of nuclei, DAPI was used.