Expression of VEGF/VPF isoforms by PEL cell lines. (A) Schematic representation of the VEGF/VPF mRNA splice variants together with the expected length of the respective RT-PCR amplification products. aa, amino acids. (B) Expression of VEGF/VPF isoforms in PEL (BC-1, BCP-1, and BCBL-1), skin fibroblast (Hs68), and prostate carcinoma (DU145) cells. Total RNA was translated into cDNA and amplified by PCR. The 3 splice variants coding for the secreted forms of VEGF/VPF were amplified from all 3 PEL cell lines. Signals for all 5 isoforms were amplified from DU145 cells and none from Hs68 cells.