Figure 6.

G47ΔUs11fluc infects and replicates in hypoxic GBM cells in vivo. (A): Brain coronal sections of GBM4 xenografts stained with hematoxylin and eosin (left) and 5-bromo-4-chloro-3-indolyl-β-d-galactopyranoside (blue; right), showing the nodular tumor (left) and viral spread in the tumor (right). (B): Immunofluorescent staining of contralateral non-tumor-bearing brain hemisphere (left panel) and GBM4 xenografts treated with PBS (middle panel) or G47ΔUs11fluc (right panel). Hypoxic areas (Hypoxyprobe, red; upper row), luciferase immunopositivity (green; middle row), and cellular nuclei (DAPI, blue; lower row) (magnification, ×10). (C): Percentages of hypoxic cells within tumors treated with PBS (white bar) and G47ΔUs11fluc (black bar). The percentages represent the number of Hypoxyprobe+ cells among total number of nucleated (DAPI-positive) cells. (D): Double immunofluorescence (merged images) using anti-Hypoxyprobe (red) and anti-luciferase (green) antibodies, with double positive cells (yellow, white arrows) (magnification, ×10 in the left panel and ×20 in the right panel). Scale = 100 μm (B, D). (E): Percentages of luciferase+ cells in normoxic (white bar) and hypoxic (black bar) tumor regions. Results from individual mice are shown in the left panel, and the averages of the three mice are shown in the right panel. The error bars represent standard deviations. Abbreviations: CTRL, contralateral; DAPI, 4′,6-diamidino-2-phenylindole; GBM, glioblastoma; n.s., not significant; PBS, phosphate-buffered saline.