HIGH-EFFICIENCY IN-VIVO GENE-TRANSFER USING INTRAARTERIAL PLASMID DNAINJECTION FOLLOWING IN-VIVO ELECTROPORATION

A novel method for high-efficiency and region-controlled in vivo gene transfer was developed by combining in vivo electroporation and intraa rterial plasmid DNA injection. A mammalian expression plasmid for the Escherichia coli lacZ gene (driven with a SV40 early promoter) was inj ected into the internal carotid artery of rats whose brain tumors (fro m prior inoculation) had been electroporated between two electrodes. T he lacZ gene was efficiently transferred and expressed in the tumor ce lls 3 days after plasmid injection. However, neither any gene transfer s nor any elevated lacZ activity was detected in tissues outside the e lectrodes. The plasmid was not transferred without electroporation. Hu man monocyte chemoattractant protein-1 cDNA was also transferred by th is method, and its long-lasting (3 weeks) expression was confirmed by using the Epstein-Barr virus episomal replicon system. The expressed m onocyte chemoattractant protein-1 protein was functional, as evident b y the presence of a large number of monocytes in the tumor tissue. Thi s method, ''electrogene therapy,'' which does not require viral genes or particles, allows genes to be transferred and expressed in desired organs or tissues, and it may lead to the development of a new type of highly effective gene therapy.