Figure 3

The effect of VHL gene knockdown on angiogenic ability of HUVEC cells in matrigel-based capillary formation assay and spheroid sprouting assay. (A) HUVEC cells from VHL knockdown groups exhibited a marked increase of capillary formation compared with control groups. At 1 hour, all cells did not form tube-structure. At 3 hours, VHL-silenced HUVEC exhibited the type of tube-structure while control cells did not. At 5 hours, all cells exhibited the type of tube-like structure with different morphologies, especially for typical features in VHL-silenced HUVEC cells (bar = 200 μm). The quantification data of tube formation assay was shown in (B). (C) Representative images of spout outgrowth after 12 hours in control and VHL-silenced HUVEC spheroids (bar = 100 μm). The length of the sprouts was measured and analyzed in (D), * represent P < 0.05.