When we tried to treat endothelial cells with Sodium polyoxotungstate (POM-1) which is a NTDPase inhibitor, to our surprise, all treated cells were dead after o/n treatment. In the end we were able to conclude that this was because of the antibiotics used in Lonza´s EBM-2 endothelial cell culture medium (with bulletkit). Most likely the adverse effects were caused by Amphotericin B together with POM-1, since with different or with no antibiotics this problem was resolved.
This is more just a comment to warn others of trying this, than a question but it would be nice to put together similar stories if you would have some similar unexpected difficulties in your experiments.