Inhibition of tumor cell invasion, dissemination and metastasis by VEGFR2 morpholinos. (A and D) VEGFR2 specific morpholinos and control morpholinos were injected into the blastoma of 1 h post-fertilization at 1–4-cell stages. DiI-labeled T241-VEGF tumor cells were implanted in the perivitelline space of 48 h post-fertilization embryos and tumor cell invasion, dissemination and metastasis were detected at days 0 and 6 post-injection. White arrowheads indicate disseminated tumor foci. (Scale bar, 500 μm.) (B and E) High-resolution micrographs of A and D, respectively to visualize single metastatic tumor cells in the trunk regions. (Scale bar, 100 μm.) (C and F) Representative 3-D micrographs of confocal images of tumors (red) and tumor vasculatures (green). (Scale bar, 10 μm.) (G) Quantification of tumor volume (n = 12/group). (H) Quantification of numbers of disseminated tumor foci (n = 12/group). (I) Averages of maximal distances of metastatic foci (n = 12/group). (J) Quantification of tumor vessel density relative to tumor size (n = 7/group). Data are represented as mean ± SEM.