Methods of cancer diagnosis and therapy targeted against a cancer stem line

Patent Number: 7,427,400

This patent covers the use of antibodies to Tie-1 and glypican-3 for the treatment of cancer, presumably by selective killing of cancer stem cells.  Tie-1 is one of the receptors for angiopoietin, which is activates endothelial cells and is critical in formation of new blood vessels (angiogenesis).  Glypican-3 is a heparan sulfate proteoglycan that is anchored to the cell membrane of numerous cancer cells, and some normal cells, it acts as a co-factor in growth factor binding and activation of receptors.

We have no idea how selective these targets are for cancer stem cells but at face value they do not appear to be very selective.  The assignee of the patent also has another target that we believe may be more selective to cancer stem cells: frizzled, a member of the wnt pathway.

In any case, the industry is very hungry for new antibodies these days, so it should be interesting to see how this area will evolve.  One point we want to make in regards to these antibody based cancer therapeutics is that many antibodies mediate effects by inducing complement dependent lysis of the cancer cells...cancer stem cells have upregulated expression of complement inhibitors.  Actually cancer cells in general have been reported to have several complement evasion mechanisms...perhaps addressing this issue may increase efficacy of the antibodies that are already on the market for treatment of cancer.

View this patent on the USPTO website.