Blood group ABO-related glycosylation of urothelial cell lines: immunocytological, enzymatic, and genetic characterization
Meldgaard, P.; Holmes, E.H.; Bennett, E.P.; Clausen, H.; Zeuthen, J.; Wolf, H.; Orntoft, T.F.
Cancer Research 54(9): 2440-2447
1994
ISSN/ISBN: 0008-5472 PMID: 8162594 Document Number: 431289
Three immortalized, human urothelial cell lines were characterized with respect to their ABO-related carbohydrate phenotypes using a panel of monoclonal antibodies directed to a series of carbohydrate epitopes (Lac, sialylated Lac, Le-a, sialylated Le-a, Le-x, sialylated Le-x, H types I and II, Le-y, Le-b, A monofucosylated types I and II, ALe-y, ALe-b, and A type III). The glycosyltransferases forming some of these epitopes (beta-1-3/4 galactosyltransferase, alpha-1-2 fucosyltransferase, alpha-1-3 galactosyltransferase, and alpha-1-3-N-acetyl-galactosaminyltransferase) were determined by enzyme assays. The ABO gene complex was analyzed by Southern blotting, Northern blotting, and polymerase chain reaction across the O deletion and across base differences between the A and B alleles. The immunocytochemical stainings showed marked differences between the three cell lines; the high grade (tumorigenic, metastatic) cell line showed difucosylated types I and II structures, and the low grade (nontumorigenic, nonmetastatic) cell lines showed monofucosylated types I and II structures. Polymerase-chain reaction genotyping of the cell lines indicated that one was OO, one was AA, and one was A plus a mutated allele. Northern blotting showed RNA encoding the A transferase. However, even though both of the A cell lines seemed to have an intact gene, which could produce A transferase and transcribed RNA, none of them showed any activity of the A gene encoded enzyme or any A-structures at the cell surface. In contrast, the three other examined glycosyltransferases were active. The three urothelial cell lines reflect in vivo findings in humans. They represent a competent system for in vitro studies of the different carbohydrate transferase genes responsible for the carbohydrate structures expressed on the cell surface in bladder tumors.