Biotech Values

[Robert C Jonson]

I'm not really sure how this provides a means for the cell to "escape" apoptosis. PS is flipped to the outer leaflet during apoptosis, at which point it is recognized by phagocytes directly (see ref). So if a cancer cell is exposing PS on the outer leaflet, it is doing the exact opposite of disguising itself... it is in fact putting out a very specific signal for phagocytes to come and engulf it. So the disguise angle makes little sense. If anything, the antibody binding the phosphatidylserine would help disguise the cell from the phagocytes.


PGS, it looks like only apoptotic cells activate the phagocytes according to Dr. Thorpe. In the non-apoptotic cancer cells, the exposed PS serves only to disguise them from an immune reaction:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3071078/

The expression of PS at the cell surface inhibits immune responsiveness and, in the case of apoptotic cells, also serves as a recognition ligand and binding site for phagocytes [4,5].