title: Specific systemic nonviral gene delivery to human hepatocellular carcinoma xenografts in SCID mice.
abstract: Systemic tumor-targeted gene delivery is attracting increasing attention as a promising alternative to conventional therapeutical strategies. To be considered as a viable option, however, the respective transgene has to be administered with high tumor specificity. Here, we describe novel polyethylenimine (PEI)-based DNA complexes, shielded by covalent attachment of polyethylene glycol (PEG), that make use of epidermal growth factor (EGF) as a ligand for targeting gene delivery to EGF receptor-expressing human hepatocellular carcinoma (HCC) cells. In vitro transfection of luciferase reporter DNA resulted in high levels of gene expression in the human HCC cell lines Huh-7 and HepG2. An excess of free EGF during transfection clearly reduced expression levels, indicating a specific EGF receptor-mediated uptake of the DNA particles. Following intravenous injection into human HCC xenograft-bearing SCID mice, luciferase expression was predominantly found in the tumor, with levels up to 2 logs higher than in the liver, which was the highest expressing major organ. Histologic investigation showed reporter gene expression (beta-galactosidase) localized to tumor cells. Assessing DNA distribution within the tumor by immunofluorescence microscopy, rhodamine-labelled transgene DNA was found to be mainly associated with HCC cells. In the liver, DNA was taken up almost exclusively by Kupffer cells and, as indicated by the low expression, subsequently degraded. In conclusion, we have shown that intravenous injection of PEGylated EGF-containing DNA/PEI complexes allows for highly specific expression of a transgene in human HCC tumors.
authors.affiliation: Department of Clinical Pharmacology, Section of Experimental Oncology, University of Vienna, Germany. markus.wolschek@akh-wien.ac.at
authors.forename: Markus F
authors.initials: MF
authors.lastname: Wolschek
authors.forename: Christiane
authors.initials: C
authors.lastname: Thallinger
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Kursa
authors.forename: Vanessa
authors.initials: V
authors.lastname: Rössler
authors.forename: Matthew
authors.initials: M
authors.lastname: Allen
authors.forename: Cornelia
authors.initials: C
authors.lastname: Lichtenberger
authors.forename: Ralf
authors.initials: R
authors.lastname: Kircheis
authors.forename: Trevor
authors.initials: T
authors.lastname: Lucas
authors.forename: Martin
authors.initials: M
authors.lastname: Willheim
authors.forename: Walter
authors.initials: W
authors.lastname: Reinisch
authors.forename: Alfred
authors.initials: A
authors.lastname: Gangl
authors.forename: Ernst
authors.initials: E
authors.lastname: Wagner
authors.forename: Burkhard
authors.initials: B
authors.lastname: Jansen
mesh_terms: D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000628:therapy*; D004563:Electrochemistry; D004815:Epidermal Growth Factor / Q000235:genetics*; D015870:Gene Expression; D017930:Genes, Reporter; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D066298:In Vitro Techniques; D007275:Injections, Intravenous; D008113:Liver Neoplasms / Q000628:therapy*; D008156:Luciferases / Q000235:genetics; D051379:Mice; D016513:Mice, SCID; D009368:Neoplasm Transplantation; D010316:Particle Size; D011092:Polyethylene Glycols / Q000494:pharmacology; D011094:Polyethyleneimine / Q000494:pharmacology; D014162:Transfection; D019076:Transgenes / Q000235:genetics; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured
chemical_list: D011092:Polyethylene Glycols; D004815:Epidermal Growth Factor; D011094:Polyethyleneimine; D008156:Luciferases