Figure 5
Epithelial cell transforming growth factor-beta signaling disrupted tight junction protein localization while enhancing migratory expression. All immunofluorescent images were taken of in ovo tumors (asterisks, tumor-stromal regions; arrows, single cells with protein mislocalization). Cytokeratin 8/18 was used as a marker for carcinoma cell identification. (A) ZO-1 was mislocalized in stromal areas of transforming growth factor-beta receptor II control (TβRIIfl/fl) tumors but maintained in transforming growth factor-beta receptor II knockout (TβRII KO) tumors. (B), (C), (D) Increased expression of α-smooth muscle actin (α-SMA) and vimentin was seen in TβRIIfl/fl tumor cells located in tumor-stromal areas. Vimentin was expressed by fibroblasts immediately surrounding TβRII KO epithelial clusters. DAPI, 4',6-diamidino-2-phenylindole; fib, fibroblasts.