天花粉毒蛋白免疫毒素对黑色素瘤细胞的体外抑制

In vitro inhibition of trichosanthin-monoclonal antibody conjugate on human melanoma cells

用单链致核糖体失活蛋白天花粉蛋白(TCS)和抗人黑色素瘤单抗(Ng76)构建了免疫毒素(Ng76—TCS),它对体外培养的人黑色素瘤细胞M21具有强烈的抑制活性,IC_(50)为5.6×10^(-10)mol/L,其毒性比游离的TCS 和Ng76的混合物高2000倍,比TCS 与正常小鼠免疫球蛋白的复合物(NIgG—TCS)高160倍,而它对非靶细胞HeLa 的IC_(50)为7.0×10^(-?)mol/L,毒性较靶细胞低125倍。结果表明,免疫毒素TCS—Ng76对体外培养的黑色素瘤细胞有很强的选择性杀伤作用.

We have constructed an immunotoxin(Ng76-TCS),which was composed of a monoclonalantibody directed against human melanoma and trichosanthin(TCS)——a single chain ribosomeinactivating protein.The cultured human melanoma cells(M21)were inhibited effectively byNg 76-TCS.The cytotoxicity of Ng76-TCS to M21 cells was 2,000-fold higher than that of free TCS and Ng76 mixture.A conjugate,which was prepared with normal mice immunoglobulinand TCS(NIgG-TCS),was 160-fold less cytotoxic to M21 cells.Meanwhile Ng76-TCS was125-fold less cytotoxic to nontarget cells Hela.These results showed that the immunotoxinNg76-TCS was a potent and specific anti-human melanoma agent.