[Antitumor effect on melanoma by in vivo direct injection of packaging cells transfected recombinant IL-2 gene].

Our previous studies showed that ex vivo transfer of human IL-2 gene into murine B16 melanoma cells resulted in the expression of IL-2 activity and had inhibitory effect on tumor growth in vivo. In this study, B16 melanoma bearing mice were injected directly with IL-2 recombinant PA317 cells. The in vivo gene transfer revealed significant reduction of tumor size and prolongation of survival of tumor bearing mice. Using slot blot analysis, the expression of IL-2 mRNA in tumor mass was detected and the IFN gamma activity was also enhanced in gene transferred mice. These results indicated that in vivo direct transfer of IL-2 recombinant retrovirual vector producing cells would induce transfer gene into tumor cells and exert its antitumor effect.