RESUMEN
To improve current angiogenic gene therapy with a vascular endothelial growth factor (VEGF)-encoding plasmid (Baumgartner et al. Circulation 1998; 97: 1114-23 [1]; Kusumanto et al. Fifth Annual Meeting of the American Society of Gene Therapy, Boston, 2002, Abstr. 621 [2]), we have generated a combination plasmid, encoding the VEGF gene and the thymidine phosphorylase (TP, also known as platelet-derived endothelial growth factor (PD-ECGF) or gliostatin (GLS)) gene: phVEGF165-TP.MB. Upon transfection in COS-7 cells both gene products were expressed and functional as shown by Western blots, ELISAs and bioassays. Culture supernatants of COS-7 cells transfected with this plasmid were able to induce endothelial proliferation. In an in vitro angiogenesis assay with recombinant proteins, TP was able to increase VEGF-induced tube formation. The phVEGF165-TP.MB plasmid is therefore a promising candidate for in vivo angiogenesis studies.