Comparative Study of Monoclonal Antibodies TURP-27 and HNK-1: Their Relationship to Neural Cell Adhesion Molecules and Prostate Tumor-associated Antigens1

The murine monoclonal antibodies TURP-27 and HNK-1 have been shown to detect antigens which are heavily expressed by benign prostatic hyperplasia and carcinoma of the prostate. Western blot analysis of prostate extracts showed that monoclonal antibodies TURP-27 and HNK-1 bound glycoproteins with molecular weights of 180,000,140,000, 120,000,100,000,90,000, and 69,000. Studies have shown that the HNK1 carbohydrate epitope may be involved in cell adhesion and that it is a component of several characterized adhesion proteins. TURP-27 was found to bind at least three of these adhesion proteins: neural cell adhesion molecules; myelin-associated glycoprotein; and a second myelin glycoprotein, PO.Western blot analysis of prostate extracts showed that an antineural cell adhesion molecule serum bound the U, 180,000 and 140,000 proteins. Based on reciprocal blocking and chemical tests, it was deter mined that the TURP-27 and HNK-1 epitopes are not identical. These data imply that the TURP-27 epitope may be a variant of the HNK-1 epitope or that the two epitopes are closely linked and that the TURP27 and HNK-1 epitopes on prostate cells are positioned on neural cell adhesion molecule-like proteins.