Glycosylation status of vitamin D binding protein in cancer patients

[Overstressed]

Hi,

I've found this on PubMed:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2786967/

And the 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.


Can anyone explain the findings ?

Best regards,
OS.

 

[globalpilot]

My understanding is that 2 of the sugars must be removed from DBP to create GCMAF. The logic circulating now in HIV and cancer is that all 3 of them are removed from DBP thus GCMAF is not created.

The above report seems to be saying that none of the 3 sugars are removed ... is that correct ?

 

[Overstressed]

Hi Globalpilot,

that's indeed what I understood too. In other words, this study is not able to replicate the findings of Yamamoto et al. Which options does it leave then ? That Gc-Maf might work through another path, or not at all ? I'm still waiting for the first paper to appear to confirm Yamamoto et al.'s findings.(e.g. eradication of HIV).

Best regards,
OS.

 

[Daffodil]

wonder if anyone can send this paper to ruggiero and see what he says ...?