[Specific targeting of mitomycin C to tumors with the use of anti-gastric cancer monoclonal antibody].

In the present study, an anti-gastric cancer monoclonal antibody, MGb2, was chosen to prepare antibody-mitomycin C (MMC) conjugate with dextran T-40 as intermediary. 20 molecules of MMC were introduced into each molecule of antibody, while the antigen-binding capacity of the antibody was kept well. The conjugate showed highly selective cytotoxicity upon human gastric cancer cell line SGC-7901. Radioimmunoimaging and biodistribution studies indicated that after conjugation with MMC via dextran T-40 as intermediary, the tumor localization capacity of the antibody was well retained. When tested in nude mice, by inoculation with human gastric carcinoma SGC-7901 in bilateral subrenal capsules, intraperitoneal injection of the conjugate daily for 6 days at the dose of 1 mg/kg of drug gave a tumor inhibitory rate of 68.67%, the result being far better than that of free MMC or irrelevant conjugate. No synergic effect was found in regard to the mixture of MGb2 with MMC.