INTERLEUKIN-2 GENE-TRANSFER IN A MURINE R ENAL-CARCINOMA MODEL (RENCA)

In this study we investigated the anti-tumor effects of Interleukin-2 gene-transfected murine renal carcinoma cells (RENCA) in the in vivo R ENCA model, Using electroporation technology, several RENCA clones wit h a stable delivery of Interleukin-2 were generated and characterized by PCR-southern blotting, Transgene expression was measured by IL-2 sp ecific ELISA showing a maximum delivery of 240 pg IL-2/10(6) cells. Th e intraperitoneal application of x-ray-inactivated RENCA transfectants was performed for 2 different tumor stages: 7 days after the orthotop ic implantation of the parental RENCA cells as a model for a localized tumor stage and 21 days after orthotopic RENCA implantation as a mode l for an advanced renal carcinoma. A significant anti-tumor-potential for the IL-2 gene therapy related to tumor growth and survival was see n in the localized stage model while the antitumor activity of IL-2 tr ansfectants in advanced carcinoma stages was clearly lower. Thus, a di rect correlation between the anti-tumor-activity of IL-2 transgene exp ression and the relation of induced effector cells to tumor volume is probable.