Dilation of Brain Veins and Perivascular Infiltration by Glioblastoma Cells in an In Vivo Assay of Early Tumor Angiogenesis

Figure 4

Fluorescence and immunofluorescence microscopy at 1, 2, and 3 weeks after grafting mCherry+ U87MG cells (red) onto the brain of cyclosporine immunosuppressed rats. (a) Microphotograph showing a tumor at 1 week after grafting (left panel). Dilation of vessels surrounded by tumor cells (right panel). Scale bars, 150 μm (left panel) and 40 μm (right panel). (b) The tumor at 2 weeks after grafting (upper panel, left). At the brain-tumor interface, dilated venules surrounded by cuffs of multilayered tumor cells (upper panel, right). Dilation of microvessels surrounded by tumor cells (arrowheads). The vessels within the tumor partly lose lectin staining (lower panel, left). Scale bars, 150 μm (upper panel, left), 70 μm (upper panel, right), and 70 μm (lower panel, left). Graph showing the diameter of microvessels in controls and in peritumor regions (lower panel, right). (c) The tumor at 3 weeks after grafting (left panel). Extreme dilation and loss of lectin staining of microvessels within the tumor (right panel). Scale bars, 150 μm (left panel) and 70 μm (right panel).

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