Zoledronate(Zometa(R))inhibits the formation of osteoblast in rat osteoblastic cell line UMR-106

Zoledronate이 UMR-106 세포의 증식과 조골세포 형성에 미치는 영향

Purpose : The purpose of this study is to identify the effect of zoledronate(Zometa(R)), which is most common nitrogen containing bisphosphonate, on survival, proliferation, and differentiation of osteoblast. Material & Methods: Twenty four cell culture plates containing essential medium were seeded with UMR-106 cell lines, at density of 5 x $10^4 cells per plates. Each plates were incubated with 5% $CO^2 incubator at $37^{\circ}C$. Starting from 2 days after incubation, cell culture medias were replaced, and added with osteogenesis induction media and 0, 0.01, 0.1, 0.5, 1, $3\muM$ of zoledronate(Zometa(R)), every 2 days, for 12 days. Control group was plates not added with zoledronate($0\muM$), and experiment group were plates added with different concentration of zoledronates(0, 0.01, 0.1, 0.5, 1, $3\muM$). Mature osteoblasts were identified with Alizarine Red staining, and protein samples were collected. Optical density was determined at wavelength of 405nm with ELISA reader. For viability analysis, cells were harvested and incubated with propidium iodide, and analysed with flow cytometry. Western blot technique was used to analyse Runx2 protein of osteoblast. Results : Secretion of bone matrix decreased as zoledronate concentration increased, and zoledronate did not effect survival rate of UMR-106 cells when measured with flow cytometer. Expression of Runx2 protein was inhibited as zoledronate concentration increased. Conclusion : From the results, we were able to identify that increase of zoledronate concentration inhibited differentiation of UMR-106 cell to osteoblast, without effecting quantity or survival rate.