T (THOMSEN-FRIEDENREICH) AND TN EPITOPE LOCATION AND THEIR SPATIAL RELATIONS TO ADHESION PLAQUES ON HUMAN BREAST-CARCINOMA CELLS - IMMUNOGOLD-SILVER STAINING STUDIES AT SCANNING ELECTRON-MICROSCOPIC LEVEL

T and Tn are pancarcinoma epitopes (EPs) which can be immunodetected i n about 90% of adenocarcinomas (CAs). To study the location of T and T n EPs and their relations to adhesion plaques on CA cells, immunogold- silver staining method was employed at scanning electron microscope (S EM) level. Human breast CA cells grown on coverslips were fixed in par aformaldehyde and glutaraldehyde, reacted with cocktails of monoclonal antibodies against T or Tn EPs, followed by incubation with 10 nm gol d conjugated goat anti-mouse immuno-globulins. The positive gold parti cle labelling was amplified with silver enhancement solution, and the specimens were then routinely critical point dried, sputter-coated wit h palladium and observed under SEM. The studies show that T and Tn EPs are not randomly distributed on CA cell surface; they are aggregated at the adhesion plaque area. These results confirm that T and Tn EPs p lay roles in CA cell adhesion, and suggest that they may represent the initial points of contact by immunoeffectors and therefore can be uti lized in immunointervention and anti-adhesion therapy against CA.