Figure 5

Cx43 immunoreactivity in brain slice culture injected with GL15 glioma cells. A, 3D projection of 15 consecutive confocal sections (0.5 μm) (×630), showing cooperation between migrating GL15 glioma cells (vimentin imunostaining, blue) with host astrocytes of the brain slice (GFAP immunostaining, red). Cx43 protein (green), is overexpressed by both tumor cells and astrocytes at the tumor margin where their processes are entwined. B, a single confocal section and two orthogonal projections (right and lower margins) corresponding to the overlayed perdendicular line. Enlarged view, of area boxed in B shows punctuate Cx43 immunoreactivity corresponding to gap junction plaques, at the interface of glioma cells and astrocytes strongly suggesting formation of heterocellular gap junctions. Note astrocyte morphologic changes which extend bipolar processes parallel to the long axes of the tumor cells