Particle-mediated gene transfer of murine interleukin-12 cDNA suppresses the growth of Lewis lung carcinoma.

We evaluated the effectiveness of the Helios gene gun system, a recently developed, commercially available gene gun device. Following skin transfection with beta-galactosidase or interleukin-12 cDNA using the gene gun, beta-galactosidase expression was detected exclusively in the epidermal cell layer, and transgene expression of IL-12 cDNA was maximal 2 days post-transfection and remained detectable for at least 5 additional days. Furthermore, particle-mediated delivery of IL-12 cDNA into epidermal cells overlying an intradermal tumor resulted in a significant suppression of tumor growth of Lewis lung carcinoma. Appreciable levels of IFN-gamma production were readily detected at the skin transfection site, and were induced from splenocytes and lymph node cells in the IL-12 treated mice. These results show that in vivo delivery of IL-12 cDNA into skin by the Helios gene gun device can have a useful routine application for cancer therapy research.