Potential usefulness of biotinylated neoglycoproteins as tumor markers.

We used several biotinylated neoglycoproteins as tumor markers to detect and localize endogenous carbohydrate-binding proteins in cultured hepatoblastoma, melanoma, and bladder carcinoma tumor cells. The neoglycoproteins used consisted of cellobiose, fucose, N-acetyl-galactosamine, N-acetyl-glucosamine, lactose, maltose, mannose, melibiose, and xylose. In addition, naturally occurring asialofetuin that was chemically disialylated was also used. Binding to the cultured tumor cells was made visible with the avidin-peroxidase technique. Depending on the type of neoglycoprotein used, markedly different expression of cytoplasmic and nuclear receptors for sugars (endogenous lectins) was obtained from rat hepatoblastoma, human melanoma, and bladder carcinoma tumor cells. The most pronounced staining differences were documented for asialofetuin and the neoglycoproteins containing fucose, N-acetyl-galactosamine, and lactose.