Figure 3From: Combination of interferon-alpha and 5-fluorouracil inhibits endothelial cell growth directly and by regulation of angiogenic factors released by tumor cells BrdUrd labeling index and tube formation in vitro. (A) In vitro angiogenesis assay showed that HUVEC formed vessel-like structures (tubes) when plated on Matrigel-coated wells. 5-FU treatment did not inhibit tube and network formation. In contrast, IFN-α caused thinner or only weakly-stained tube-like structures. IFN/5-FU also inhibited tube formation compared to the control and caused only weak staining of the tube-like structures, similar to IFN-α alone. (B) 5-FU alone and IFN/5-FU caused significant decreases in BrdUrd labeling index compared with the control and IFN-α alone (p < 0.01). There was no difference in the index between 5-FU alone and IFN/5-FU combination (A, B). There was a significant difference in the number of capillary connections, defined as cross-points consisting of three tubes, among the control, 5-FU alone and IFN-α, IFN/5-FU (p < 0.01).Back to article page