RESUMEN
The Thomsen-Friedenreich (TF) antigen is a cryptic disaccharide structure on human erythrocytes which can be exposed by neuraminidase treatment and which is supposed to be expressed in an unmasked form on some carcinoma cells. For its detection in addition to auto-, allo- and heteroantisera, PNA (peanut lectin) is being applied. In the present studies the mouse monoclonal antibody (MoAb) raised to asialoglycophorin from human erythrocytes was used. The MoAb 22.19 is of mouse IgM isotype and is specifically binding to beta-D Gal-1-3 alpha-D GalNAc. The human urothelial cell lines maintained and characterized earlier were analyzed using indirect immunofluorescence assays. Among the spectrum of cell lines tested, five out of six cell lines belonging to the transformation grade III category (invasive in vitro and tumorigenic in nude mice) expressed TF antigen. The relationship between expression of TF antigen and other earlier defined biological traits related to malignant phenotype is discussed.