Figure 8.

VEGFR inhibitors suppress tumour vascularization but promote tumour cell invasion. (A) Tumour vascularization was significantly suppressed by VEGFR inhibitors KRN633 or Sunitinib at both concentrations (Wilcoxon test, p < 0.01). The results were scored at 1dpi as the percentage of Tg(fli:GFP) embryos showing no (white), minor (grey) and extensive (black) neovasculature formation towards the FGF-T-MAE tumour cell mass. Representative images of each class are shown. Data are representative of > three independent experiments (each n > 30). (B) Expansion of the localized tumour mass was inhibited by 0.1 µm VEGFR inhibitor KRN633 or Sunitinib. Images are representative of > five independent experiments (each n > 30). (C) Tumour cell invasion at the posterior end of the CHT was significantly enhanced by VEGFR inhibitor KRN633 (Wilcoxon test, p < 0.01 for 0.5 µm). The results were scored at 1dpi, as the percentage of embryos showing phenotypes of no invasion (white), 1 cell invasion (grey) and > 1 cell invasion (black). Representative images of each class are shown. Data are representative of ≥ 10 independent experiments (each n > 30). (D) Microangiography using tetramethylrhodamine dextran. No leakage was detected at 24 h after administration of 0.1 µm VEGFR inhibitor KRN633 or Sunitinib. Data are representive of three independent experiments (each n > 3). (E) Immunohistochemistry against the tight junction protein ZO-1. Normal junctions were detected between endothelial cells at the posterior end of the CHT at 24 h after administration of 0.1 µm VEGFR inhibitor KRN633 or Sunitinib. Data are representative of three independent experiments (each n > 5). Scale bars = 25 µm. Images were acquired using a Leica TCS SPE confocal microscope with a × 20 dry objective (A–D) or a × 63 water objective (E)