title: Long-term increase in mVEGF164 in mouse hindlimb muscle mediated by phage phiC31 integrase after nonviral DNA delivery.
abstract: Peripheral vascular disease (PVD), characterized by insufficient blood supply to extremities, can be a devastating illness. Although many gene therapy strategies for PVD using vascular endothelial growth factor (VEGF) have resulted in increased blood vessel formation, the vessels are often impermanent and regress after therapy, probably because of the short-lived VEGF expression mediated by gene therapy vectors (14 days or less). phiC31 integrase is a recombinase originally isolated from a bacteriophage of Streptomyces. This integrase performs efficient chromosomal integration of plasmid DNA into mammalian genomes that results in long-term transgene expression. In this study, gene transfer was achieved by intramuscular injection of VEGF and integrase plasmid DNAs into the tibialis anterior muscle in the mouse hindlimb, followed by electroporation of the muscle with needle electrodes. We observed VEGF levels significantly above background 40 days after injection in animals that received phiC31 integrase and the VEGF plasmid. Site-specific integration of plasmid DNA in the chromosomes of muscle tissue was verified by polymerase chain reaction at a common integration site. These results suggest the possible utility of the phiC31 integrase system to treat ischemic disease.
authors.affiliation: Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA.
authors.forename: Joylette L
authors.initials: JL
authors.lastname: Portlock
authors.forename: Annahita
authors.initials: A
authors.lastname: Keravala
authors.forename: Carmen
authors.initials: C
authors.lastname: Bertoni
authors.forename: Solomon
authors.initials: S
authors.lastname: Lee
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Rando
authors.forename: Michele P
authors.initials: MP
authors.lastname: Calos
mesh_terms: D000818:Animals; D001435:Bacteriophages / Q000201:enzymology / Q000235:genetics; D018274:Electroporation / Q000379:methods; D005260:Female; D015316:Genetic Therapy / Q000379:methods; D006614:Hindlimb / Q000098:blood supply*; D019426:Integrases / Q000235:genetics; D007511:Ischemia / Q000235:genetics / Q000628:therapy*; D051379:Mice; D010957:Plasmids; D011995:Recombination, Genetic / Q000235:genetics; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics
chemical_list: D042461:Vascular Endothelial Growth Factor A; D014764:Viral Proteins; C467480:vascular endothelial growth factor A, mouse; D019426:Integrases