Glycosylation status of vitamin D binding protein in cancer patients.

Abstract

On the basis of the results of activity studies, previous reports have suggested that vitamin D binding protein (DBP) is significantly or even completely deglycosylated in cancer patients, eliminating the molecular precursor of the immunologically important Gc macrophage activating factor (GcMAF), a glycosidase-derived product of DBP. The purpose of this investigation was to directly determine the relative degree of O-linked trisaccharide glycosylation of serum-derived DBP in human breast, colorectal, pancreatic, and prostate cancer patients. Results obtained by electrospray ionization-based mass spectrometric immunoassay showed that there was no significant depletion of DBP trisaccharide glycosylation in the 56 cancer patients examined relative to healthy controls. These results suggest that alternative hypotheses regarding the molecular and/or structural origins of GcMAF must be considered to explain the relative inability of cancer patient serum to activate macrophages.

• Authors: Douglas S Rehder, Randall W Nelson, Chad R Borges
• Journal: Protein science : a publication of the Protein Society (Protein Sci) Vol. 18 Issue 10 Pg. 2036-42 (Oct 2009) ISSN: 1469-896X [Electronic] United States
• PMID: 19642159 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Macrophage-Activating Factors
• Trisaccharides
• Vitamin D-Binding Protein

Topics

• Female
• Glycosylation
• Humans
• Immunoassay
• Macrophage-Activating Factors (blood, metabolism)
• Male
• Neoplasms (blood, metabolism)
• Spectrometry, Mass, Electrospray Ionization
• Trisaccharides (chemistry, metabolism)
• Vitamin D-Binding Protein (blood, chemistry, metabolism)