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

Figure 3

Fluorescence microscopy at 1 week after grafting mCherry+ U87MG cells onto the brain of cyclosporine immunosuppressed rats. (a) Collateral branching (upper panel, arrows) of microvessels contributing to the tumor (red). Dilated vessels surrounded by tumor cells (lower panel, arrowheads) that spread along perivascular spaces. Scale bars, 100 μm. (b) Vessels with αSMA expression do not sprout. Scale bar, 25 μm. (c) Progressive increase of microvessel diameter and density from control brain (left) to peritumor (center) and tumor (right) regions. Scale bar, 70 μm. (d) Quantification of microvessel diameter, branching, and density.

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