Immunotherapy of xenografted human bladder cancer in nude mice using monoclonal antibody.

A murine monoclonal antibody with IgG3 isotype and k-light chains has been produced against a human bladder cancer cell line, TSGH-8301. Radioimmunoassay and immunofluorescent staining revealed that the highly reactive tumor-associated antigen was located on the cell surface of TSGH-8301 transitional cell carcinoma cells. The monoclonal antibody possessed direct and complement-mediated cytotoxicity to TSGH-8301 cancer cells as shown by in vitro microcytotoxicity test. Further trials on the immunotherapy of xenografted tumors in nude mice using the monoclonal antibody demonstrated that the therapeutic efficacy was dose-dependent and closely related to tumor burden.