CELL-SURFACE ANTIGENS OF HUMAN LUNG-TUMORS DETECTED BY MOUSE MONOCLONAL-ANTIBODIES - DEFINITION OF BLOOD-GROUP-RELATED AND NON-BLOOD-GROUP-RELATED ANTIGENIC SYSTEMS

The pattern of antigen expression in human non‐small‐cell cancers of various histiological subtypes has been studied. Mouse monoclonal antibodies (MAbs) were generated following immunizations with cell lines of squamous, adeno‐ and anaplastic large‐cell carcinomas of the lung. Seven nonblood‐group‐related antigens were defined in addition to 5 antigens related to blood‐group determinants. Detailed specificity was established with a large panel of cultured cell lines and normal and neoplastic tissues. MAb F‐18 reacted in direct tests with the immunizing squamous lung carcinoma cell line, with 5 out of 5 choriocarcinoma cell lines, but with no other cell lines. No expression of F‐18 antigen was observed in any normal or malignant tissue examined. The other 6 nonblood‐group‐reactive MAbs (F‐7, F‐8, F‐11, F‐15, F‐16 and F‐17) could be distinguished by their reactivity on a panel of cultured cells and tissues. One MAb in this group (F‐17) reacted strongly with 19/35 lung tumor cell lines, 32/76 other tumor‐derived cell lines, cultured normal kidney cells and fetal lung fibroblasts. This antibody did not react with any normal adult tissues examined, but did react with several cancer tissues including 1/17 lung tumors, 2/4 ovarian cancers and 1/5 colon tumors. Immunoprecipitation tests revealed that 5 of the antigens were glycoproteins: F‐18 (Mr > 200,000), F‐15 (Mr 44,000), F‐16 (Mr 90,000), F‐17 (Mr 95,000) and F‐8 (Mr 95,000). Four MAbs detected Y blood‐group antigen (Ley), only 2 of which were able to agglutinate O erythrocytes. Another antibody detected X blood‐group antigen (Lex). Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company