Targeted gene transfer into head and neck squamous cell carcinoma by nanosecond pulsed laser-induced stress waves.

The search for new strategies to improve patient outcome and organ preservation is of great clinical interest in head and neck squamous cell carcinoma (HNSCC) treatment, and gene therapy is expected to play a promising role. In this study, we demonstrated the value of laser-induced stress waves (LISWs) as a novel method for nonviral gene transfer for gene therapy in HNSCC. The in vitro and in vivo transfection efficiency as well as in vitro cytotoxicity for HNSCC was investigated. Green fluorescent protein (GFP) expression and cell viability were analyzed in vitro after administration of a GFP-expressing plasmid or cationically modified GFP-expressing plasmid with LISW application. Luciferase expression in xenograft tumors was also quantitatively analyzed in vivo. The GFP gene was successfully transfected into HNSCC cells in vitro by LISW application. The cationically modified plasmid demonstrated enhanced transfection efficiency. LISWs are not associated with adverse effects after application to cells in vitro. The reporter genes were also successfully transfected into HNSCC tumors in vivo by LISW application. This technique is site specific, safe, and easily applicable for practical purposes. LISW gene therapy with therapeutic factors that inhibit tumor growth therefore has the potential as a future treatment for HNSCC.