Identification of a tumor-associated antigen in cervical carcinoma by two dimensional (crossed) immunoelectrophoresis

Two-dimensional immunoelectrophoresis was used to evaluate 8 cervical cancer speciments, 11 other gynecologic tumors, and 5 specimens of normal cervix. Antigens were water-soluble tissue extracts and antisera prepared in rabbits. When tested against antisera to cervical cancer, cancer antigens showed 14-17 precipitin lines whereas normal cervix showed 10-16. A single heavy heterogeneous precipitin line with an electrophoretic mobility of 0.58 relative to bovine albumin was observed in all cervical cancer specimens but not in normal cervical or other tumor specimens. Further evidence for the uniqueness of this antigen was sought by enhancement (addition of another antigen to the first phase of electrophoresis which increased the size of common peaks) and suppression (addition of another antiserum to the second phase, whereby the peak size of components to which both sera have antibody was decreased). The specific precipitin line was neither suppressed by the addition of antisera to normal tissue nor enhanced when normal tissue antigen was added to the tumor antigen preparation. More conclusively, adsorption of the tumor antiserum with normal tissue had no effect on the unique tumor-associated precipitin line, whereas all other precipitin lines were removed. This antigen was common to other cervical tumors because enhancement was demonstrated with three other cervical tumor specimens. The identification of a distinct and separate antigen associated with cervical carcinoma will permit further characterization and possible development of immunodiagnostic methods.