title: [Effects of irradiation on proliferation and differentiation of MC3T3-E1 osteoblastic cells in vitro].
abstract: OBJECTIVE
  The aim of this study is to investigate the effects of irradiation on the proliferation and differentiation of MC3T3-E1 osteoblastic cells.
  
  
  METHODS
  MC3T3-E1 cells were irradiated 24 h after initial seeding. Gamma-radiation was administered at 0, 4, and 8 Gy as single doses by using a 60Co source. Cell proliferation was assessed at days 1, 3, 5, and 7 post-irradiation by using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenylte-trazolium bromide assay. The collagen secretion of the cells was measured through sirius red staining at day 12 post-irradiation. The expressions of osteogenesis-related genes were assessed through real time fluorescence quantitative polymerase chain reaction at day 16 post-irradiation. The matrix mineralization caused by cells was evaluated through alizarin red staining at day 28 post-irradiation.
  
  
  RESULTS
  The cells exposed to 4 Gy or 8 Gy demonstrated significantly lower proliferation rates compared with the non-irradiated group. Doses of 4 Gy or more significantly inhibited the expressions of osteogenesis-related genes (Osterix and osteocalcin). Collagen secretion and cell mineralization were significantly reduced by the 8 Gy dose.
  
  
  CONCLUSIONS
  60Co gamma-rays dose-dependently suppress the proliferation, collagen secretion, and mineralization of MC3T3-E1 cells. Furthermore, radiation seems to dose-dependently inhibit the expressions of osteogenesis-related genes of the cells.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Li
authors.forename: Yimin
authors.initials: Y
authors.lastname: Zhao
authors.forename: Nianbao
authors.initials: N
authors.lastname: Zha
authors.forename: Zhen
authors.initials: Z
authors.lastname: Shu
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
mesh_terms: D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D006801:Humans; D066298:In Vitro Techniques; D010006:Osteoblasts; D015675:Osteocalcin; D010012:Osteogenesis
chemical_list: D015675:Osteocalcin