EFFECTS OF GELONIN IMMUNOCONJUGATE OF MONOCLONAL-ANTIBODY MSN-1 TO ENDOMETRIAL ADENOCARCINOMA ON ANTIGEN-PRODUCING TUMOR-CELLS IN-VITRO

Missile therapy, which destroys cancer cells specifically, has been co nsidered to be an effective modality for treatment of carcinoma. We ha ve developed a monoclonal antibody MSN-1 (immunoglobulin class: IgM), of which the immunogen is the endometrial adenocarcinoma cell line SNG -II, which strongly reacts with endometrial adenocarcinomas. We descri be an immunoconjugate consisting of the MSN-1 and a plant hemitoxin na med gelonin which has revealed to assume selective cytotoxicity agains t the SNG-II in a colony formation assay in vitro. The results of our study suggest that the 'inhibitory concentration' or IC50, of the MSN- 1-gelonin immunoconjugate against the SNG-II was 188 fold that of gelo nin alone. These results indicated that the MSN-1-gelonin immunoconjug ate exhibited highly selective cytotoxicity to endometrial adenocarcin oma, which expressed an epitope against the MSN-1, and it is suggested that the MSN-1-gelonin immunoconjugate has possibility of clinical ap plication to treatment of endometrial adenocarcinomas.