Figure 2

Tumor promoters induce rapid disassembly of epithelial tight junctions and adherens junctions. Confluent HPAF-II cell monolayers were treated for 5 h with either vehicle, OI-V, or TPA (each, 1 μM). Localization of AJ proteins (E-cadherin, β-catenin) and TJ proteins (occludin, ZO-1) was determined by fluorescence labeling and confocal microscopy. Both tumor promoters induce translocation of AJ and TJ proteins from the areas of cell-cell contact into cytosol (arrows). Bar, 20 μm.