Complex cancer gene therapy in mice melanoma

Objective. We investigated the effects of continuous cancer gene therapy, including APC engineering and local stimulation of the immune system in a mice melanoma model.

Materials and methods. B16 melanoma cells were injected into C57/Bl6 mice intradermally. The overlying dermis or the tumor were shot with different plasmids using a gene gun every 4th day starting 8 days after tumor implantation. Control groups were mice without any therapy or gene therapy as described above with the empty plasmid. Therapy was: group I, IL-12 and IL-2; group II, IFN-γ/B7.1; group III, IFN-γ/B7.1, IL-12, and IL-2.

Results. The median survival time of all therapy groups was significantly enhanced. The longest median survival was in the IL-12/IL-2 group. Tumor growth was reduced in all therapy groups. Control groups suffered a higher rate of metastasis and had fewer inflammatory cells at the tumor site.

Conclusions. Continuous therapy with the gene gun is easy to handle and shows good results. Therapy with genes for IL-12 and IL-2 was superior to that with additional IFN-γ/B7.1 or IFN-γ/B7.1 alone. APC engineering is clearly less sufficient in the case of the B16 melanoma.