Detection of a ganglioside antigen associated with small cell lung carcinomas using monoclonal antibodies directed against fucosyl-GM1.

Monoclonal antibodies with an apparent specificity for fucosyl-GM1 (Fuc-GM1) were produced by the immunization of mice with Fuc-GM1 adsorbed to Salmonella minnesota bacteria and fusion of the spleen cells with the myeloma cell line Sp 2/0. The antibodies detected Fuc-GM1 with a unique ceramide composition containing 2-hydroxy fatty acids in 11 of 12 cases of small cell carcinoma of the lung. Trace amounts of Fuc-GM1 were detected in 1 of 11 squamous epithelial cell lung carcinomas. Fuc-GM1 was also detected in 1 of 7 pancreas carcinomas but was not detected in any of the other cancers analyzed. Small amounts of Fuc-GM1 without 2-hydroxy fatty acids were detected in normal adult pancreas, spleen, and brain but could not be detected in normal lung tissue. Fuc-GM1 with 2-hydroxy fatty acids is suggested to be a specific ganglioside associated with small cell lung carcinomas. The monoclonal antibodies directed against Fuc-GM1 may be useful for specific immunodiagnosis of small cell lung carcinomas and might also be useful for specific immunotherapy of these malignant tumors.