[Monoclonal antibody against human lung carcinoma]

Spleen cells of BALB/c mice immunized with human pulmonary adenocarcinoma cell LTEP-a2 were fused with murine myeloma cell SP 2/0, from which 4 hybridomas (2 A7, 2 E9, 4 F2 and 5 F11) were obtained. Indirect immunofluorescence test showed that these 4 monoclonal antibodies reacted with human lung cancer cells, but not with 2 BS or the lymphocytes and red blood cells in 4 different ABO groups of 10 persons. Using ABC immunoperoxidase stain technique, these 4 antibodies showed negative reaction with 9 tissue types from the normal subject and fetus but could react with 52-83% of the 29 human lung carcinomas and 64-92% of the 24 non-small cell lung cancers (non-SCLC). When 5 F11 was combined with 2 A7 or 2 E9, the percentage of positive stain was 100% in 24 non-SCLC. The results of indirect immunofluorescence stain showed that strong membrane stain by 5 F11 and membrane stain by 4 F2 were obtained, indicating that these antibodies could recognize antigens on cancer cell membrane. It is suggested that a mixture of 5 F11 and other antibodies be useful in the diagnosis and treatment of lung cancer. Molecular weight of the antigens recognized by the 4 antibodies was determined by SDS-PAGE and immunoblot technique to be 47 KD (2 A7), 67 KD (2E9), 40 KD (4F2) and 56 KD (5 F11).