Expression of glycoconjugates in pancreatic, gastric, and colonic tissue by Bauhinia purpurea, Vicia villosa, and peanut lectins.

Abstract

We have earlier prepared a pancreatic cancer-associated mucin, whose altered carbohydrate structure was recognized by Vicia villosa (VVA), Bauhinia purpurea (BPA), and peanut (PNA) lectins and which was found preferentially in the sera of patients with pancreatic or gastric cancer. Cancer-associated structures of the sugar chain on serum antigen may reflect those occurring in malignant tissues. Accordingly, we investigated the tissue distribution of carbohydrate structures reactive to these lectins by using lectin histochemistry in pancreatic cancer, gastric cancer, and colonic cancer tissue specimens and in their normal counterparts. VVA showed a higher affinity for pancreatic cancer (77.5%), gastric cancer (89%), and colonic cancer (87%) cells than for the cells of their normal counterparts, whose affinity was 0%, 41.7%, and 36.4%, respectively. PNA showed a higher affinity for pancreatic (70%) and colonic cancer cells (86.5%). BPA failed to show significant binding differences between neoplastic and normal cells in any of the pancreatic, gastric, or colonic tissue specimens. It did, however, bind to intraductal contents in most of the pancreatic cancer tissues but bound to intraductal contents in only a few chronic pancreatitis and normal pancreatic tissues. VVA and PNA did not bind to intraductal contents in any of the normal, chronic pancreatitis, or pancreatic cancer tissues. These results imply that, among the lectins used so far, VVA has the highest affinity for neoplastic cells, and it may provide a supplement for use in the pathologic diagnosis of malignant diseases.(ABSTRACT TRUNCATED AT 250 WORDS)