DETECTION OF MEMBRANE-ASSOCIATED HUMAN CHORIONIC-GONADOTROPIN AND ITSSUBUNITS ON HUMAN CULTURED CANCER-CELLS OF THE NERVOUS-SYSTEM

Cultured human cancer cells from the nervous system, which included br ain cancers, neuroblastomas, medulloblastomas, and retinoblastomas, we re analyzed by analytical flow cytometry for the presence of membrane- associated human chorionic gonadotropin (hCG), its subunits, and fragm ents. Live cells and a panel of monoclonal antibodies directed to epit opes located in three different sites of the hCG molecule were used in the analysis. For in vivo studies, the cultured human glioma cells we re grown in athymic (nude) mice, and their tumors were excised and fix ed in Bouin's fixative, and embedded in paraffin for subsequent immuno cytochemical analysis of tissue sections. Cells from a benign uterine leiomyoma were used as a negative control. Membrane-associated and cyt oplasmic hCG, its subunits, and its fragments were present in cells fr om all the cancers studied. These results correlate with our in vitro and in vivo studies which showed the presence of translatable levels o f hCG beta mRNA in all cancers, including the cancers of the nervous s ystem, proving that these malignant neoplasms are no different from ca rcinomas, sarcomas, malignant lymphomas, or leukemias in that they all have the same biochemical denominator. Our findings give the scientif ic basis for the use of active and/or passive immunization against hCG for prevention or as a primary or adjuvant therapy for these types of cancers.