IMMUNOTHERAPY OF BLADDER-CANCER WITH CYTOKINE GENE-MODIFIED TUMOR VACCINES

This study explored the use of cytokine gene-modified tumor cells as c ellular vaccines for the treatment of bladder cancer. The mouse MBT-2 tumor is an excellent model for human bladder cancer. This carcinogen- induced tumor of bladder origin resembles human bladder cancer in its etiology and histology and responds to treatment in a manner similar t o that of its human counterpart. In a previous study we have shown tha t interleukin 2 (IL-2)-secreting, irradiated, MBT-2 cell preparations were capable of curing animals from orthotopically established tumors and engendered protective immunological memory in the cured animals. I n this study we have compared the effectiveness of several cytokines a nd found that while IL-1 alpha, IL-1 beta, and gamma-interferon were o nly weakly effective in the therapeutic vaccination protocol, granuloc yte-macrophage colony-stimulating factor was almost as effective as bu t not superior to IL-2, as reported previously for another tumor model system. Induction of cytotoxic T-lymphocyte correlated only poorly wi th the therapeutic benefit of the cytokine gene-modified tumor cell pr eparations, questioning its prognostic value for the development of im proved genetically modified tumor vaccines.