Angiogenic properties of PC-3 cells overexpressing AKR1C3 on Matrigel. (A) PC-3 cell-mediated HMEC-1 tube formation was performed in a co-culture system on Matrigel basement membrane matrix. Formation of HMEC-1 tubes was imaged at 24 hours after HMEC-1 co-culture with either PC3-mock or PC3-AKR1C3 transfectants. (B) Quantification of HMEC-1 tube formation. The number of EC tubes were counted; and results were compared between PC3-mock and PC3-AKR1C3 transfectants and presented as mean ± SEM from 12 experiments for the 4 independent clones. The number of HMEC-1 tubes formed were also determined by pre-treating PC-3 transfectants with 20 µM AG1042 or 10 µM LY294002; and results were presented as mean ± SEM from at least 3 independent assays. * indicates P < 0.05 between PC3-mock and PC3-AKR1C3 transfectants.