HSV-tk/ganciclovir-based non-viral gene therapy in human oral cancer cells


Nejat Düzgüneş: 0000-0001-6159-1391


Biomedical Sciences

Document Type

Conference Presentation

Conference Title

31st Annual Meeting of the American Association for Dental Research


San Diego, CA

Conference Dates

March 6-9, 2002

Date of Presentation


Journal Title

Journal of Dental Research

Journal ISSN


Journal Volume Number


First Page



Oral squamous cell carcinoma (OSCC) is a well-diagnosed epithelial malady with a high rate of morbidity. A number of gene therapy strategies for the treatment of OSCC are being explored. The purpose of this study was to deliver the Herpes Simplex Virus thymidine kinase (HSV-tk) "suicide gene" to OSCC cells using cationic lipid-DNA complexes, which may have fewer safety concerns than viral vectors. Transfection of human oral cancer cell lines, HSC-3, H357, H413 and H376 was optimized using b-galactosidase (b-gal)-expressing plasmids and four transfection reagents: Fugene, Escort, Lipofectamine 2000, and GenePORTER. Fugene and Escort+Transferrin(Tf) provided the highest efficiency of transfection. About 40% and 10% of HSC-3 cells were positive for b-gal staining after transfection with Fugene and Escort+Tf, respectively. The delivery of the HSV-tk gene to HSC-3 cells by Fugene or Escort+Tf followed by ganciclovir treatment for 8 days, resulted in >80% cytotoxicity, determined by the Alamar Blue assay. In contrast, only less than 5% of H357, H413 and H376 cells were positive for b-gal staining. Nevertheless, in H357 cells about 80% and 50% cytotoxicity was observed with Fugene and Escort+Tf, respectively. In H413 cells, the viability was 40% with Fugene and 20% with Escort+Tf, while in H376 cells, it was reduced to 60% only with Fugene. Thus, cytotoxicity in the presence of ganciclovir was observed despite the very low efficiency of transfection. We conclude that (i) lipid-DNA complexes may be used for suicide gene therapy of OSCC and (ii) a high percentage of cell killing can be achieved despite the low efficiency of transfection, possible due to diffusion of phosphorylated ganciclovir into neighboring cells via gap junctions.

This document is currently not available here.