Isolation and Identification of Human Lung Tumor-associated Antigens1

Other authors reported the extraction of lung TM's soluble in 50% ammonium sulfate,but also demonstrated these antigens not to be cross-reactive with CEA (36, 37). Two antigens extractable with 0.85% NaCI solution were isolated by Mclntire and Sizaret (26). These antigens did not cross react with CEA, AFP, a-2 H-globulin, or f3-fetoprotein. Wat son et a!. (42, 43) utilized an immunoadsorption column to which normal lung-soluble proteins were coupled to isolate antibodies to lung TM from rabbit antisera. One of their lung TM's was cross-reactive with embryonic extracts while the other was not. Both of these latter lung TM's were found in extracts of several histopathological types of lung tumors. Recently, Hollinshead et a!. (15, 16) successfully isolated and purified a lung TM and demonstrated its im munological specificity by means of skin testing. These data, along with the detection of a circulating lung TM by cross-over immunoelectrophoresis by Viza et al. (41), sup port the existence of human lung TM. However, no attempt has been made to adequately characterize, identify, and/or correlate the above findings. We report the isolation, characterization, and identifica tion of 3 human lung TM's found in significant concentra tions in several histopathological types of lung tumors.