Ectopic expression of Snail1 in DLD-1 cells induces morphological changes, downregulation of E-cadherin expression, and cell dissociation. (A) Immunoblot determination of Snail1 protein levels in Snail+ and control DsRed+ cells using either anti-HA or anti-Snail. Anti-vinculin was used as a loading control. (B) Phase contrast micrographs showing morphological (epithelial to fibroblastic) changes in response to Snail1 expression. Immunofluorescence staining with anti-HA and DAPI was carried out to determine the nuclear localization of Snail-HA. Bar, 25 µm. (C) Immunostaining with either anti-E-cadherin or anti-occludin of Snail+ and DsRed+ control cells. Bar, 50 µm. (D) DsRed+ cells detach from the dish as cell sheets while Snail+ cells become either single cells or form small aggregates. Bar, 100 µm.