Co-existence of MSC cells and head and neck cancer cells promoted EMT. (A) Immunofluorescence staining for ß-catenin in SCC-25, MSC, sorted-SCC and fused MSC/SCC cells demonstrated both plasma membrane and cytoplasmic localization. (B) Western blot analysis of EMT associated genes were evaluated for the expression of E-cadherin and vimentin. (C) Flow cytometry revealed epithelial EpCAM and mesenchymal CD90 expression. (D) Transwell migration assay showed differential mobility of naïve SCC, sorted-SCC and fused MSC/SCC cells. (E) Cell migration capacities of the 4 cell types seeded in collagen had differential rates of escape from the plugs was quantitated by light microscopy (*P < 0.05). EMT, epithelial to mesenchymal transition; MSC, Mesenchymal stem cells; SCC, squamous cell carcinoma.