2 Elucidation of communication-of-information mechanism between osteoblasts and osteoclasts : N-bisphosphonates regulate proliferation and mRNA expression on human osteoblast-like cells

Abstract

Bisphosphonates (BPs), synthetic analogs of pyrophosphate, are potent inhibitors of bone resorption and are being successfully used with increasing frequency in the treatment of osteoporosis. We investigated whether BPs (etidronate, alendronate and risedronate) affect the proliferation and mRNA expression of type l collagen, osteocalcin and alkalinephosphatase on human osteoblast-like Saos 2 cells. When alendronate and risedronate were co-cultured with Saos-2 cells, proliferation decreased compared both with the controls and with Saos-2 cells cultured with etidoronate. The mRNA expression was analyzed using a reverse trancriptase-polymerase chain reaction. The expression of mRNA, type l collagen, osteocalcin and alkalinephosphatase were decreased by treatment with alendronate and rise-dronate, but not by treatment with etidronate. These results indicate that N-BPs may influence the activity of osteoblasts, not but non-N-BPs.