Abstract
We have assessed the ability of bispecific fusion proteins to improve adenovirus-mediated transfer of therapeutic and marker transgenes. We constructed an expression vector that can be easily modified to synthesize a variety of fusion proteins for retargeting adenoviral gene therapy vectors to cell surface markers, which are differentially expressed between normal and cancer cells. Adenoviral transduction can be improved in a number of tumour cell lines which overexpress EGFR (epidermal growth factor receptor) or uPAR (urokinase-type plasminogen activator receptor), but which have only low levels of endogenous hCAR (human coxsackie B and adenovirus receptor) expression. Up to 40-fold improvement in Β-galactosidase transgene expression was seen using an EGFR retargeting protein, and up to 16-fold using a second fusion protein targeting uPAR. In vitro, our uPAR retargeting fusion protein improved the sensitivity to adenoviral herpes simplex virus thymidine kinase/ganciclovir by an order of magnitude, whereas in vivo, our EGFR retargeting protein is able to significantly delay tumour growth in rodent animal models in a dose-dependent manner. The cassette design of our fusion protein constructs offers a flexible method for the straightforward synthesis of multiple adenoviral retargeting proteins, directed against a variety of tumour-associated antigens, for use in clinical trials.
Original language | English (US) |
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Pages (from-to) | 1000-1010 |
Number of pages | 11 |
Journal | Gene Therapy |
Volume | 17 |
Issue number | 8 |
DOIs | |
State | Published - Aug 2010 |
Keywords
- EGFR
- adenovirus
- bladder cancer
- hCAR
- retargeting
- uPAR
ASJC Scopus subject areas
- Molecular Medicine
- Molecular Biology
- Genetics