Common Glycoproteins Expressing Polylactosamine-Type Glycans on Matched Patient Primary and Metastatic Melanoma Cells Show Different Glycan Profiles

Recently, we reported comparative
analysis of glycoproteins which
express cancer-specific N-glycans on various cancer
cells and identified 24 glycoproteins having polylactosamine (polyLacNAc)-type N-glycans that are abundantly present in malignant cells
[Mitsui et al., J. Pharm. Biomed. Anal. 2012, 70, 718−726]. In the present study, we applied the technique
to comparative studies on common glycoproteins present in the matched
patient primary and metastatic melanoma cell lines. Metastatic melanoma
cells (WM266-4) contained a large amount of polyLacNAc-type N-glycans in comparison with primary melanoma cells (WM115).
To identify the glycoproteins expressing these N-glycans,
glycopeptides having polyLacNAc-type N-glycans were
captured by a Datura stramonium agglutinin
(DSA)-immobilized agarose column. The captured glycopeptides were
analyzed by LC/MS after removing N-glycans, and some
glycoproteins such as basigin, lysosome-associated membrane protein-1
(LAMP-1), and chondroitin sulfate proteoglycan 4 (CSPG4) were identified
in both WM115 and WM266-4 cells. The expression level of polyLacNAc
of CSPG4 in WM266-4 cells was significantly higher than that in WM115
cells. In addition, sulfation patterns of chondroitin sulfate (CS)
chains in CSPG4 showed dramatic changes between these cell lines.
These data show that characteristic glycans attached to common proteins
observed in different stages of cancer cells will be useful markers
for determining degree of malignancies of tumor cells.