195. Therapeutic Angiogenesis in Mouse Ischemic Heart after Intramyocardial Injection of a Novel Two Gene Plasmid Vector Co-Expressing High Levels of Human VEGF and bFGF Genes

Abstract

Therapeutic angiogenesis has been shown a great promise to treat ischemic cardiovascular diseases. Many growth factor cytokines with angiogenic activity have been investigated for such purpose. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) are the two best studied angiogenic cytokines in treating ischemic cardiovascular diseases both in animal models and clinical trials. And synergistic effect in therapeutic angiogenesis from using VEGF and bFGF either as recombinant proteins or genes has been reported by several groups. In the context of cardiovascular gene therapy, development of gene therapy vehicles capable of delivering multiple genes is desired. In this study, two angiogenic cytokine genes, human VEGF165 and bFGF, were incorporated into a multiple-gene expression plasmid vector, p2-MCS. Instead of using the viral-derived IRES, we employed independent transcriptional units to drive these two genes, respectively. In vitro transient transfections, our data showed that p2-VEGF-FGF vector was capable of co-expressing high levels of both hVEGF and bFGF genes simultaneously. The expression levels of both genes from the p2-hVEGF-FGF vector were comparable to that achieved by using vectors carrying either VEGF or bFGF gene alone. Using mouse ischemic heart model, the efficacy of therapeutic angiogenesis after intramyocardial injection with p2-VEGF-FGF vector is investigated and compared to that achieved from injection with vectors carrying either of the two genes alone.