HER2-targeted gene transfer.
Selective transfer of genes to specific cells remains a barrier to successful utilization of somatic gene therapy. We hypothesized that the human epidermal growth factor receptor-2 (HER2, also called ErbB2), a membrane tyrosine kinase highly expressed in many epithelial tumors, could be an immunological target for gene transfer. To test this hypothesis in vitro, we non-covalently linked a luciferase expression vector (pRSVLuc) to a humanized HER2 antibody (rhuMAbHER2) covalently modified with poly-L-lysine bridges (PL). This complex (PL-rhuMAbHER2) was tested for its ability to direct gene transfer to HER2 expressing cells in vitro using NIH3T3 (HER2 nonexpressing) and NIH3T3.HER2 (HER2 expressing) cell lines as a model system. Twenty-four hours after exposing NIH3T3.HER2 cells to the PL-rhuMAbHER2-pRSVLuc complexes and 100 microM chloroquine, luciferase expression was 180-fold higher than that obtained from a conjugate made with an isotype-matched antibody against an irrelevant target. Exposing the HER2-expressing adenocarcinoma cell lines BT474 and SKBR3 to the HER2-targeted complexes also resulted in successful gene transfer and expression. Gene transfer was specific for the HER2 receptor, because preincubation of HER2-expressing cells with unconjugated rhuMAbHER2 decreased complex-mediated luciferase expression by 95%. These studies suggest that HER2 may be an appropriate target for selective gene transfer and that PL-rhuMAbHER2-DNA complexes may be a useful vehicle for directing gene transfer to cells that express HER2.
Foster
B J
BJ
University of Iowa College of Medicine, Department of Internal Medicine, Iowa City 52242, USA.
Kern
J A
JA
D016475:3T3 Cells; D000596:Amino Acids / Q000737:chemistry; D000818:Animals; D000911:Antibodies, Monoclonal; D005786:Gene Expression Regulation; D018014:Gene Transfer Techniques; D006801:Humans; D008156:Luciferases / Q000235:genetics; D046911:Macromolecular Substances; D051379:Mice; D011107:Polylysine; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured
D000596:Amino Acids; D000911:Antibodies, Monoclonal; D008156:Luciferases; D046911:Macromolecular Substances; D011107:Polylysine; D018719:Erb-b2 Receptor Tyrosine Kinases