Preclinical studies for gene therapy of head and neck cancers using the HSV-tk/GCV strategy

The present study has used the suicide gene Herpes Simplex Virus-thymidine kinase (HSV-tk) and ganciclovir (GCV) strategy. A 2 kb sequence of HSV-tk was subcloned into the retroviral vector resulting in a recombinant vector, LTKSN, which was transfected into a packaging cell-line, PA317 and selected on G418. The highest expressing clone, PTK-16 was used for in vitro experiments. Intra-tumoural injections of PTK-16 followed by GCV treatment, in a HNSCC xenograft model in nude mice, showed a significant reduction in the viable tumour volume (p=0.009). These results will form the basis for future clinical trials in HNSCC.