EXPRESSION OF GLYCOCONJUGATES IN PANCREATIC, GASTRIC, AND COLONIC TISSUE BY BAUHINIA-PURPUREA, VICIA-VILLOSA, AND PEANUT LECTINS

We have earlier prepared a pancreatic cancer-associated mucin, whose a ltered carbohydrate structure was recognized by Vicia villosa (VVA), B auhinia purpurea (BPA), and peanut (PNA) lectins and which was found p referentially in the sera of patients with pancreatic or gastric cance r. Cancer-associated structures of the sugar chain on serum antigen ma y reflect those occurring in malignant tissues. Accordingly, we invest igated the tissue distribution of carbohydrate structures reactive to these lectins by using lectin histochemistry in pancreatic cancer, gas tric cancer, and colonic cancer tissue specimens and in their normal c ounterparts. VVA showed a higher affinity for pancreatic cancer (77.5% ), gastric cancer (89%), and colonic cancer (87%) cells than for the c ells of their normal counterparts, whose affinity was 0%, 41.7%, and 3 6.4%, respectively. PNA showed a higher affinity for pancreatic (70%) and colonic cancer cells (86.5%). BPA failed to show significant bindi ng differences between neoplastic and normal cells in any of the pancr eatic, gastric, or colonic tissue specimens. It did, however, bind to intraductal contents in most of the pancreatic cancer tissues but boun d to intraductal contents in only a few chronic pancreatitis and norma l pancreatic tissues. VVA and PNA did not bind to intraductal contents in any of the normal, chronic pancreatitis, or pancreatic cancer tiss ues. These results imply that, among the lectins used so far, VVA has the highest affinity for neoplastic cells, and it may provide a supple ment for use in the pathologic diagnosis of malignant diseases. Lectin -binding glycoproteins presenting in cancer tissues may be released in to the bloodstream, as confirmed by the identification of BPA- and VVA -reactive antigens in the sera of cancer patients, including those wit h pancreatic cancer, in our previous study.