EMMPRIN induces capillary-like structure formation by endothelial cells via VEGF and VEGFR-2. HMEC-1 transfected with VEGF, VEGFR-2 siRNA, or scrambled siRNA were seeded on top of a fibrin gel and treated with Emp for 24 hours in serum-free medium. (A) Capillary-like structure formation by HMEC-1 cells transfected with siRNA-targeting common sequence of VEGF isoforms. A mix of VEGF and bFGF and serum-free medium was used as positive and negative controls, respectively. VEGF₁₂₁, VEGF₁₆₅,VEGF₁₈₉, VEGFR-1, and VEGFR-2 transcript quantification by qRT-PCR. (B) Capillary-like structure formation by HMEC-1 cells transfected with VEGFR-2 siRNA. VEGFR-2 transcript quantification by qRT-PCR. Results are presented as the mean of 3 independent experiments and expressed as a percentage of the cumulative tube length obtained for the positive control set at 100%. Columns indicate means of relative expression to TBP housekeeping gene of 3 independent experiments; and bars, SD. *P < .05.