MONOCLONAL ANTIBODIES IN ONCOLOGY ':" MARIA I. COLNAGHI, SILVANA CANEVARI, RENATO MARIANI-COSTANTINI, SYLVIE M~iNARD, SILV1A MIOTTI, ELDA TAGLIABUE Divisione di Oucologia Sperimentale E, Istituto Naziortale per lo Studio e la Cura dei Tumori, Milauo The application of classical hybridoma technology to the study of human tumors resulted in the generation of a variety of monoclonal antibodies (MoAbs) that identify several tumor-associated antigens. Monoclonal reagents with selected speciflcities are therefore available in increasing number and their potential for applications in clinical oncology is under investigation. Even MoAbs not specific for cancer cells may prove useful in complement ing conventional diagnostic procedures in clinical oncology, provided they are able to discriminate between tumor cells and normal ceils in specific sites. We have recently reported ~: the generation and characterization of routine MoAbs obtained by immunization against the human breast carcinoma line MCF-7 or human ovarian carcinoma cells from a surgical specimen. The po- tential applications of these reagents in clinical oncology are summarized in tab. 1. The described objective implies an exact determination of the antibody specificity, which can be achieved by properly planning the characterization of the MoAbs. The screening methodologies and the material tested to this aim are reported in tab. 2. We identified two MoAbs, both of IgM class, which appear promising and their reactivities, in respect to the material reported in tab. 2, are described in tab. 3. The MoAb MBrl has been shown to identify a determinant on the sugar moiety of a glycolipidic complex; the MoAb MOv2 has been shown to identify a determinant on a high molecular weight glycoprotein. The reactivity of MBrl Key-words: Iraraunohistocheraical d~agno, is." Mo~u~clonal ay~tibodies: Tumor diagnosis. ~:This work was supported in part by a grant fi'om the Cotzsiglio Nazionale delle Ricerche (CNR), Roma, Italy, 'Progetto Finalizzato Cotttrollo della Crescita Ne@lastica' (contract no. 80.02371.96) and by the Associaz.io~ze Italiana per le Ricerche sial Cancro. La Ricerca Clin. Lab. li, 997, 1984. 297