Abstract
Nucleoside kinases from several species are investigated as suicide genes for treatment of malignant tumors by combined gene/chemotherapy. In the present study, we have investigated a novel strategy where nucleoside kinase proteins are directly delivered to cells without delivery of genetic material. We used a mix of a trifluoroacetylated lipopolyamine and dioleoyl phosphatidylethanolamine (BioPorter) to form protein–lipid complexes containing either recombinant herpes simplex virus type-1 thymidine kinase or Drosophila melanogaster multisubstrate deoxyribonucleoside kinase. We showed that the nucleoside kinase containing protein–lipid complexes was imported into human osteosarcoma and Chinese hamster ovary cell lines by endocytosis and that the enzymes were delivered to the cytosol and nucleus. The nucleoside kinases imported into the cell lines retained enzymatic activity, and the cells treated with the enzyme–lipid complexes showed increased sensitivity to nucleoside analogues, such as ganciclovir, (E)-5-(2-bromovinyl)-2′-deoxyuridine, and 1-β-d-arabinofuranosylthymine. Our results show that direct delivery of suicide gene proteins to cells may be an alternative approach to conventional suicide gene therapy strategies.
Footnotes
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The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked advertisement in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵1 Supported by the Swedish Medical Research Council and the Swedish Cancer Society (project 4729-B02–01XAB).
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↵2 To whom requests for reprints should be addressed, at the Division of Clinical Virology F68, Karolinska Institute, Huddinge University Hospital, S-14186 Stockholm, Sweden. Phone: 46-8-58581306; Fax: 46-8-58587933; E-mail: magnus.johansson{at}mbb.ki.se
- Received February 18, 2003.
- Revision received July 4, 2003.
- Accepted July 21, 2003.
- ©2003 American Association for Cancer Research.
Volume 63, Issue 20
