Detection of membrane-associated human chorionic gonadotropin and its subunits on human cultured cancer cells of the nervous system.

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