Tissue antigens in ovarian carcinoma.

Five tissue antigens have been identified which appear in carcinoma arising in the ovary. Antisera to a variety of human tissues were absorbed with a saline extract of normal ovary as well as plasma; five distinct antigens (A1-A4, TA) were detected in ovarian tumor extracts as well as in normal tissues. A1, A2, and A3 were widely distributed in normal tissues while A4 was found principally in buffy coat blood cells and spleen, and Ta was mainly associated with normal cervix but was variably detected in liver and lung. Heating the tumor extract to 56 degrees resulted in inactivation of A1, A2, and A3. A4 was inactivated at 80 degrees, whereas TA was stable at 100 degrees. Pronase treatment readily abolished A3 activity, more slowly inactivated A1, A2, and A4, and only very slowly destroyed TA. Partial separation of the antigens was obtained by Sephadex G-200 chromatography. TA from individual benign and malignant tumors as well as normal cervix appears to be the same molecule by criteria of immunodiffusion, immunoelectrophoresis, and gel filtration. The potential use of these antigens as tracers of ovarian carcinoma is indicated.