The tumor association of a trisaccharide epitope: specificity of antiserum developed to galactose beta1->3 N-acetyl glucosamine beta1-->3 galactose.

Abstract

A pentasaccharide carbohydrate epitope described by Nozawa et at (1) is expressed by 35% of the neoplastic tissue samples from patients with endometrial cancer but not by normal endometrium. This epitope was detected using a human monoclonal antibody (HMST-1) produced by fusion of lymphocytes from an endometrial cancer patient. We chemically linked a synthetically produced nonreducing terminal trisaccharide portion of this pentasaccharide to bovine serum albumin to create an effective immunogen, Galbeta1->3GlcNAcbeta1->3Gal-BSA. A rabbit polyclonal antibody was produced and tested against panels of tumor and normal tissues. In contrast to the results obtained with HMST-1, 100% of the endometrial adenocarcinomas we studied stained with this polyclonal antiserum while normal endometrium was non-reactive. The reactivity with other tyes of adenocarcinomas was approximately 80%, whereas most normal tissues were not reactive with the antiserum. Immunological specificity analysis was performed with structurally related carbohydrates and this shows the fine specificity reaction of the antiserum. This antigen may be clinically useful for immunolocalization and for immunotargeting.