Biochemical characterization and tissue distribution of the Cora antigen, a cell surface glycoprotein differentially expressed on malignant and benign gastrointestinal epithelia.

摘要: A monoclonal antibody designated Cora was isolated which discriminates between malignant and benign colon epithelium. It identifies a novel, variably glycosylated membrane glycoprotein. Expression of the antigen shown to be characteristic for gastrointestinal carcinomas (100% tested colorectal carcinomas, 70% gastric carcinomas) but could not detected on normal tissues using histochemical methods frozen tissue sections. An extensive survey revealed that has very restricted distribution pattern, being only alveoli lung, granulocytes, bone marrow. Polyacrylamide gel electrophoresis immunoprecipitates prepared from [35S]methionine, 125I, or [3H]glucosamine labeled carcinoma cell lines showed consists group glycoproteins ranging in apparent molecular weight 75,000 95,000. Following treatment with neuraminidase, weights were reduced (65,000 85,000) size heterogeneity remained. Culturing cells presence tunicamycin, inhibits N -linked glycosylation, removed this under these conditions precipitated major band an 33,000. Because can distinguish epithelia, expression may associated process transformation tissue.