Figure 2From: Contribution of gap junctional communication between tumor cells and astroglia to the invasion of the brain parenchyma by human glioblastomasEffects of inhibition of heterocellular coupling between GL15 cells and astrocytes. A, Photomicrographs in co-cultures (preloading method) showing heterocellular coupling without (upper panel) or with addition of the inhibitor CBX. GL15 donor cells pre-labeled with a non-diffusing membrane-bound dye (DiI, red) and loaded with a fluorescent gap junction-permeable dye (calcein, green) were seeded on a monolayer of unlabeled astrocytes. Functional heterocellular GJC is visualized as the transfer of calcein from DiI-labeled donor cells (small arrows) to surrounding recipients cells. Donors cells appear yellow because of the merge of red and green labeling. CBX reduced the number of calcein-containing (green) recipient astrocytes, (×200). B, Histograms representing mean values of a minimum of three independent runs as in A (range 4 – 6; n = 160 to 225 donor cells per group ± SEM). (***, p < 0.001). C and D, histograms of the migration indices of GL15 in brain slices without or with CBX, illustrating decreased migration in the treated group (mean values ± SEM. **, p < 0.01). E, Cumulative migration indices plotted against time in co-cultures where GL15 cell spheroids were plated upon an astrocyte monolayer, without or with CBX; (S - S0) / S0 values were measured every 12 h, for 48 h. Integrated areas under the two curves in arbitrary units were compared, p < 0.0001.Back to article page