Ectopic expression of VEGF-C in PC-3 cells and orthotopic tumors. PC-3 cells were stably transfected with a vector containing human VEGF-C (PC-3/VEGF-C) or empty vector (mock). One cell clone expressing VEGF-C at a high level, and one control clone (PC-3/mock) were selected for further studies. ELISA analysis of VEGF-C protein concentration in cell lysates (A) and in conditioned media (B) revealed increased expression in PC-3/VEGF-C cells compared with PC-3/mock cells. Data are expressed as means ± SD ng/mL, corresponding 106 cells. (C) Western blot analysis revealed that PC-3 cell clones expressed mainly 29/31 kD form of VEGF-C. Detectable levels of 21 kD form were not seen. β-actin control was from cell lysates corresponding to the collected conditioned medium.