Epithelial-to-mesenchymal transition in pancreatic ductal adenocarcinoma: Characterization in a 3D-cell culture model

Figure 2 HPAF-II ultrastructure. A: Electron microscopy of HPAF-II culture grown in a 2D-monolayer showing two cells partially overlapping and exhibiting microvilli (Mv). Scale bar = 1 μm; B-D: Ultrastructural features of HPAF-II cells grown in 3D-spheroids. Adjacent cells located at the periphery of the spheroid show microvilli (Mv) in the apical domain and junctional complexes (jc). In B, some cells exhibit a pale and markedly irregular nucleus (N). Some adjacent cells delimit a lumen-like structure (L). Scale bar = 1.5 μm. C, D: Adjoined cells are connected by junctional complexes (jc) in their apical-lateral domains and by numerous adherens junctions (arrows) in their lateral domains. In D, microvilli are densely packed; at their core, actin microfilaments can be seen extending into the apical cytoplasm. C, D: scale bar = 1.5 μm.