THE IDENTIFICATION OF GLIOBLASTOMA-ASSOCIATED, FUCOSE-CONTAINING GLYCOPROTEINS INDUCED BY RETINOIC ACID

We have used a tumorigenic glioblastoma cell line, SNB-19, as a model system to identify fucose-containing glycoprotein candidates for tumor suppressor function. Glycoproteins were analyzed after treatment with a variety of chemical differentiating agents by two-dimensional SDS-P AGE, followed by electroblotting and visualization using the fucose-sp ecific lectin, Ulex europeaus I. Approximately 25 fucose-containing gl ycoproteins (FUCGLAPs) were routinely visualized in control extracts u sing 60-70 mug of protein per gel and staining with Vectastain ABC kit s. Retinoic acid induced the most marked change in FUCGLAP expression, causing a fivefold increase in one FUCGLAP (M(r) = 125 kDa, pI = 6.6) . Neither butyric acid, dibutyryl cAMP, nor combinations of these comp ounds gave a similar result. Using this model system and analytical ap proach, it should be possible to identify, isolate, and evaluate glyco protein oligosaccharides for their tumor modulating capability.