Figure 6.

Effect of anti–FGF-2 antibody on VEGF expression by NIH 3T3 cells transfected with LMW FGF-2 or HMW FGF-2 cDNA. Western blotting analysis of medium conditioned by LMW FGF-2 or HMW FGF-2 trans-fectants (clones 1 and 3 shown in Fig. 4) in the absence or in the presence of the indicated concentrations of anti-FGF-2 antibody (αFGF-2) or n.i. (n.i.) IgG (50 μg/ml). (A) LMW FGF-2 transfectants (clone 3). (B) HMW FGF-2 transfectants (clone 1). FGF-2 expression by these clones is shown in Fig. 4 A. The cells were preincubated for 3 h in serum-free medium with or without the indicated concentrations of anti– FGF-2 antibody or n.i. IgG; the medium was replaced with fresh, serum-free medium with or without anti–FGF-2 antibody or n.i. IgG and the incubation was continued for 9 h. The conditioned medium was analyzed by Western blotting under reducing conditions with anti-VEGF antibody as described in Materials and Methods. Recombinant VEGF₁₆₅ (10 ng) was run as a control in the leftmost lane of the gels shown in A and B. This experiment was repeated three times with similar results.