N-linked sugar chains of mouse B16 melanoma cells and their low-metastasizing variant selected by wheat germ agglutinin.
The N-linked sugar chains of metastasizing mouse B16 melanoma cells (F1) and their wheat germ agglutinin-resistant variant (Wa4-b1) showing a dramatic decrease in metastasizing and tumorigenic potentials were liberated from their membrane glycoproteins by hydrazinolysis, and their structures were comparatively analysed. The results indicated that both cell lines contain high-mannose-type and bi-, tri- and tetraantennary complex-type oligosaccharides, and their ratios are similar. However, outer chain moieties of tri- and tetraantennary oligosaccharides of the variant are extensively fucosylated, resulting in the formation of X-antigenic determinants, Gal beta 1----4(Fuc alpha 1----3)GlcNAc. Oligosaccharides containing X-antigenic determinants amounted to 71% of the total complex-type oligosaccharides. Fucosylation occurs on every N-acetyllactosamine unit and the number of the determinants ranges from one to three in triantennary oligosaccharides and one to four in tetraantennary oligosaccharides. The determinants occur predominantly in non-sialylated forms, although some are in sialylated forms. Oligosaccharides containing non-sialylated X-antigenic determinants and those containing sialylated X-antigenic determinants are approximately in the ratio 6:1. Since no significant difference was found in the extent of branching of complex-type oligosaccharides of the two cell lines, it is suggested that non-fucosylated outer chains are important for the expression of metastasizing potential by the tumour cells.
Kawano
T
T
Department of Biochemistry, University of Tokyo, Japan.
Takasaki
S
S
Tao
T W
TW
Kobata
A
A
D000818:Animals; D002240:Carbohydrate Sequence; D000939:Epitopes / Q000737:chemistry; D014644:Genetic Variation; D008545:Melanoma / Q000737:chemistry*; D008562:Membrane Glycoproteins / Q000737:chemistry*; D051379:Mice; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D012794:Sialic Acids; D014407:Tumor Cells, Cultured; D014909:Wheat Germ Agglutinins
D000939:Epitopes; D008562:Membrane Glycoproteins; D009844:Oligosaccharides; D012794:Sialic Acids; D014909:Wheat Germ Agglutinins; D019158:N-Acetylneuraminic Acid