Bone-bound bisphosphonate inhibits growth of adjacent non-bone cells.

The conventional view of the mode of action of bisphosphonates is that they are taken up by bone surfaces and then ingested by bone-resorbing osteoclasts, the activity of which they inhibit through their actions on the enzyme, farnesyl pyrophosphate (FPP) synthase. This model suggests that these compounds should only have effects on osteoclasts, and does not provide an explanation for their other actions, such as the epithelial abnormalities seen in osteonecrosis of the jaw, and their possible prolongation of disease-free survival in some malignancies. The present studies set out to determine whether cells other than osteoclasts are affected by bone-bound bisphosphonates.