title: [Proteomics research of bufalin-induced apoptosis in osteosarcoma cell lines].
abstract: OBJECTIVE
  To study the apoptosis inducing effects of bufalin on various human osteosarcoma cells and the concerning molecular mechanisms.
  
  
  METHODS
  MTT assay was used to detect the growth inhibition rates of osteosarcoma cells U-20S, U-20S/MTX300, SaOS-2, IOR/OS9 treated with bufalin in different concentrations and times. The apoptosis of cells was observed flow cytometry 48 h following bufalin treatment. The proteomic techniques were used to separate and compare the treated and control groups 48 h after bufalin-incubation. Then, the proteomic results were validated by western blot.
  
  
  RESULTS
  Bufalin inhibited the growth of human osteosarcoma cells U20S, U20S/MTX300 (methotrexate resistant cells), SAOS2, IOR/OS9 in a dose- and time-dependent manner. The 72 h IC50 were (37.43 +/- 4.1), (32.24 +/- 5.3) nmol x L(-1) in U20S,U20S/MTX300 cells,respectivly. Flow cytometry showed that the apoptosis cells were increased following bufalin treatment. The protein expression profile showed 24 differentiated expression proteins. Among these proteins, the level of an anti-apoptotic protein, heat shock protein 27 (Hsp27) decreased significantly and the result was then validated by western blot. Ectopic expression of Hsp27 could reduce the bufalin-induced apoptosis remarkably in U20S and U20S/MTX300 cells.
  
  
  CONCLUSIONS
  Bufalin could inhibit the cell growth and induce apoptosis on human osteosarcoma cells. The effect of bufalin may be related to the joint intervention with multiple protein targets. Among them, downregulation of Hsp27 plays a critical role in the bufalin-induced apoptosis in human osteosarcoma cells.
authors.forename: Xian-Biao
authors.initials: XB
authors.lastname: Xie
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Wen
authors.forename: Jun-Qiang
authors.initials: JQ
authors.lastname: Yin
authors.forename: Hong-Yi
authors.initials: HY
authors.lastname: Liao
authors.forename: Chang-Ye
authors.initials: CY
authors.lastname: Zou
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Huang
authors.forename: Jing-Nan
authors.initials: JN
authors.lastname: Shen
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002018:Bufanolides / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D012516:Osteosarcoma / Q000473:pathology*; D040901:Proteomics
chemical_list: D000970:Antineoplastic Agents; D002018:Bufanolides; C022777:bufalin