Unique alpha 2, 8-polysialylated glycoproteins in breast cancer and leukemia cells.

Abstract

The N-linked oligosaccharides of neural cell adhesion molecule and the rat brain voltage-dependent sodium channel alpha subunit are specifically modified by alpha 2, 8-polysialic acid chains. Until now, this carbohydrate modification has been observed only on these two proteins in mammalian cells. We have identified 180-260 kDa proteins in RBL rat basophilic leukemia cells and MCF7 human breast cancer cells that are modified by alpha 2, 8-polysialylated oligosaccharides. Immunofluorescence microscopy and Northern analysis confirmed that these proteins are neither the neural cell adhesion molecule nor the sodium channel alpha subunit. The presence of authentic alpha 2, 8-polysialic acid on the basophilic leukemia and breast cancer proteins was confirmed by the elimination of anti-polysialic acid antibody staining after treatment with the alpha 2, 8-polysialic acid-specific endo-N-acetylneuraminidase. The failure of peptide N-glycosidase F to completely remove alpha 2, 8-polysialic acid bearing oligosaccharides from the RBL protein, and the sensitivity of these oligosaccharides to beta-elimination, suggests that alpha 2, 8-polysialic acid may be found on O-linked oligosaccharides. This identification of new alpha 2, 8-polysialylated proteins in RBL basophilic leukemia and MCF7 breast cancer cells suggests that alpha 2, 8-polysialylation of glycoproteins may be more widespread than originally believed, especially in cancer cells.

• Authors: C M Martersteck, N L Kedersha, D A Drapp, T G Tsui, K J Colley
• Journal: Glycobiology (Glycobiology) Vol. 6 Issue 3 Pg. 289-301 (Apr 1996) ISSN: 0959-6658 [Print] England
• PMID: 8724137 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Neural Cell Adhesion Molecules
• RNA, Messenger
• Sialic Acids
• Sialoglycoproteins
• polysialic acid
• Amidohydrolases
• Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase

Topics

• Amidohydrolases
• Animals
• Breast Neoplasms (chemistry, genetics)
• Carbohydrate Conformation
• Cell Membrane (metabolism)
• Female
• Humans
• Leukemia, Basophilic, Acute (genetics, metabolism)
• Leukemia, Experimental (genetics, metabolism)
• Molecular Structure
• Neural Cell Adhesion Molecules (chemistry, genetics)
• Peptide-N4-(N-acetyl-beta-glucosaminyl) Asparagine Amidase
• RNA, Messenger (genetics, metabolism)
• Rats
• Sialic Acids (analysis)
• Sialoglycoproteins (chemistry)
• Transfection
• Tumor Cells, Cultured