Recognition of a High Molecular Weight Glycoprotein (HMW-GP) Associated with Rat Colon Cancer Cells by Rat Monoclonal Antibodies

Abstract
In this report we describe an auto-immunogenic tumor associated high molecular weight glycoprotein (HMW-GP) present on most rat colon carcinomas as detected by syngeneic monoclonal IgM antibodies. The HMW-GP has an apparent molecular weight of more than 106 D and carries several epitopes for various lectins, carbohydrate specific mouse monoclonal antibodies and four rat syngeneic monoclonal antibodies. The epitope defined by the 10B12 rat monoclonal antibody is present in colon carcinoma tissue, but only in very low amounts in normal gastro-intestinal-tissue. The epitope is present at multiple sites on the large molecule and is shown to be sterically related, but not identical to determinants for Dolichos biflorus lectin and a mouse mAB binding to blood group A. The 10B12 mAB binding is insensitive to boiling, reduction with mercaptoethanol and treatment with trypsin, but abolished by pretreatment of the antigen with sodium periodate or neuraminidase. The epitopes defined by 1G6 and 1F6 rat monoclonal antibodies are present both in tumor tissue and in normal colon mucosa and the antibody binding is increased after treatment with both neuraminidase and sodium periodate.

This publication has 21 references indexed in Scilit: