Comparative studies on the structural features of O-glycans between leukemia and epithelial cell lines.

Recently, we developed an automated apparatus for rapid releasing of O-glycans from mucin-type glycoproteins and proteoglycans (Anal. Biochem. 2007, 362, 245−251; 2007, 371, 52−61). In the present paper, we released O-glycans from some leukemia and epithelial cells using the apparatus, and compared the profiles of O-glycans among these cells after fluorescent labeling of the released glycans with 2-aminobenzoic acid. The fluorescent labeled glycans were analyzed using a combination of HPLC and off-line MALDI-(QIT)TOF mass spectrometry We found that leukemia cells generally showed simple glycan profiles and commonly contained sialyl-T (NeuAcα2-3Galβ1-3GalNAc) and disialyl-T (NeuAcα2-3Galβ1-3(NeuAcα2-6)GalNAc) antigens as major O-glycans. In contrast, epithelial cancer cell lines usually showed extremely complex profiles. We found that polylactosamine-type O-glycans were abundantly present in MKN45 cells. Especially, we found characteristic glycans, of which Galβ1-3 residue of core1 structure is modified wi...