[Combined interleukin-2 and herpes simplex virus thymidine kinase gene therapy for head and neck squamous cell...

To assess the efficacy of combined interleukin-2 (IL-2) and herpes simplex virus thymidine kinase (HSV-TK) gene therapy for murine head and neck squamous cell carcinoma (HNSCC).

Ad IL-2 or/and Ad HSV-TK were injected into the tumor tissues directly after the murine HNSCC model was established. DL312 or PBS was used as control and ganciclovir (GCV) was used at 25 mg/kg for 7 days in Ad HSV-TK gene treatment groups. Tumor size was measured before and after treatment to evaluate the response to treatment. Cytotoxic T-lymphocyte (CTL) and natural killer (NK) assays were performed and IL-2 expressions were also measured after IL-2 gene transfection.

HNSCC tumor growth was significantly inhibited following combined IL-2 and HSV-TK gene therapy as compared to other groups (P < 0.05). Increased levels of IL-2 protein expression was found in combined and single IL-2 treated groups. The combination and IL-2 treated groups produced greater activities of CTL and NK than that of the controls.

IL-2 gene therapy can efficiently induce antitumor immunity of the host and enhance antitumor effects of HSV-TK. Combined IL-2 and HSV-TK gene therapy could significantly inhibit HNSCC tumor growth in the murine model.