title: Photochemically enhanced transduction of polymer-complexed adenovirus targeted to the epidermal growth factor receptor.
abstract: BACKGROUND
  The development of methods for specific delivery of genes into target tissues is an important issue for the further progress of gene therapy. Biological and physical targeting techniques may be combined to redirect gene therapy vectors to specific cells and enhance gene transfer.
  
  
  METHODS
  The polymer poly(2-(dimethylamino)ethyl methacrylate) (pDMAEMA) was conjugated with avidin or poly(ethylene glycol) (PEG) and complexed with adenovirus serotype 5 (Ad5). Targeting of polymer-coated Ad5 to the epidermal growth factor receptor (EGFR) was accomplished by the binding of biotin-EGF to pDMAEMA-avidin. A photochemical treatment procedure using photosensitizer and light was applied to increase transduction with EGFR-targeted viral complexes.
  
  
  RESULTS
  pDMAEMA-avidin efficiently enhanced transduction through unspecific viral uptake into cells, while pDMAEMA-PEG provided charge shielding of the complexes and increased the specificity to EGFR when biotin-EGF ligands were used. Transduction of PEG-containing, EGFR-targeted viral complexes was inhibited by 66% in coxsackie and adenovirus receptor (CAR)-deficient RD cells and by 47% in CAR-expressing DU 145 cells in receptor antibody experiments. The photochemical treatment had a substantial effect on transduction, enhancing the percentage of reporter gene positive cells from 20% to 75% of the total viable RD cell population and from 10% to 70% in DU 145 cells.
  
  
  CONCLUSIONS
  Photochemical treatment of cells infected with targeted viral vectors exhibiting a neutral surface charge is a potent method for enhancing transgene expression.
authors.affiliation: Department of Radiation Biology, Institute for Cancer Research, Rikshospitalet-Radiumhospitalet HF, Montebello, N-0310 Oslo, Norway. anettbo@ulrik.uio.no
authors.forename: Anette
authors.initials: A
authors.lastname: Bonsted
authors.forename: Birgit Øvstebø
authors.initials: BØ
authors.lastname: Engesaeter
authors.forename: Anders
authors.initials: A
authors.lastname: Høgset
authors.forename: Gunhild M
authors.initials: GM
authors.lastname: Maelandsmo
authors.forename: Lina
authors.initials: L
authors.lastname: Prasmickaite
authors.forename: Christine
authors.initials: C
authors.lastname: D'Oliveira
authors.forename: Wim E
authors.initials: WE
authors.lastname: Hennink
authors.forename: Jan Hein
authors.initials: JH
authors.lastname: van Steenis
authors.forename: Kristian
authors.initials: K
authors.lastname: Berg
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D001360:Avidin; D004337:Drug Carriers; D066246:ErbB Receptors / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D018014:Gene Transfer Techniques; D015316:Genetic Therapy / Q000379:methods*; D006801:Humans; D008297:Male; D008689:Methacrylates; D009757:Nylons; D010777:Photochemistry; D011092:Polyethylene Glycols; D011471:Prostatic Neoplasms / Q000473:pathology; D018233:Rhabdomyosarcoma, Embryonal / Q000473:pathology; D012509:Sarcoma / Q000473:pathology; D014161:Transduction, Genetic; D014407:Tumor Cells, Cultured; D014594:Uterine Neoplasms / Q000473:pathology
chemical_list: D004337:Drug Carriers; D008689:Methacrylates; D009757:Nylons; C407037:poly(2-(dimethylamino)ethyl methacrylate); D001360:Avidin; D011092:Polyethylene Glycols; D066246:ErbB Receptors