Change in glycosylation of membrane glycoproteins after transfection of NIH 3T3 with human tumor DNA.

Altered glycosylation of membrane glycoproteins was demonstrated in NIH 3T3 cells transformed by transfection with DNA from human neuroblastoma and bladder carcinoma cell lines. The oncogenes of these two cell lines have been identified as N-ras and c-H-ras-1, respectively. The fucose-labeled membrane glycopeptides of transfection-induced transformants had decreased binding to concanavalin A-Sepharose when compared in dual-isotope experiments to those from NIH 3T3 cells, whereas binding to lentil lectin-Sepharose and leukoagglutinating phytohemagglutinin-agarose was increased. Binding affinities to these immobilized lectins lead to the interpretation of the results as a decrease in biantennary glycopeptides with a simultaneous increase in tri- or tetraantennary glycopeptides. Sephadex G-50 profiles also indicated a size increase of the glycopeptides of the transformants. None of these changes was growth related. This altered glycosylation, representing a heretofore unreported effect of the onc genes, may be necessary for the transformed phenotype.