Distribution of junctional proteins in TC-EC monolayers.
BCECF-labeled A375 cells were added to confluent ECs grown onto cross-linked gelatin and were allowed to spread for 16 hours. The mosaic TC-EC monolayer was fixed and stained in red fluorescence for (A) EC junctional proteins—(i) VE-cadherin, (ii) β-catenin, (iii) PECAM-1, and (iv) ZO-1—or for (B) some members of the tetraspanin family (i) CD9, (ii) CD81, (iii) CD151, or (iv) the associated α3 integrin. The locations of melanoma cells are indicated (*) (originally labeled in green fluorescence). Bars, 15 μm. Histograms show the fluorescence intensity quantification along the white line traced on the immunofluorescence images; a and b correspond to start and end points, respectively. TC-EC heterotypic junctions are indicated by arrows, and EC-EC and TC-TC homotypic junctions are indicated by arrowheads in the fluorescence histograms.
