title: Inhibitory effect of oridonin on proliferation of RPMI8226 cells and the possible underlying mechanism.
abstract: OBJECTIVE
  To observe the effects of oridonin on proliferation and apoptosis of myeloma RPMI8226 cells and to investigate the potential underlying mechanisms.
  
  
  METHODS
  RPMI8226 cells were treated with various concentrations of oridonin. Cell proliferation was analyzed using the thiazolyl blue tetrazolium bromide method. Ultramicrostructure was observed by transmission electron microscopy. Annexin-V/PI staining and flow cytometry was performed to determine cell apoptosis. Expression of apoptosis-related proteins was evaluated by western blot analysis.
  
  
  RESULTS
  Oridonin suppressed the proliferation of RPMI8226 cells and induced apoptosis in a time-and dose-dependent manner. Transmission electron microscopy confirmed apoptotic morphology upon treatment with 20 μmol/L oridonin and western blot revealed decreased expressions of the apoptosis suppressors survivin, Bcl-2 and pro-caspase-3 proteins, and the increased expression of the apoptosis inducer Bax.
  
  
  CONCLUSIONS
  Our results show that oridonin exhibits an inhibitory effect on the proliferation of RPMI8226 cells and induces apoptosis. This is associated with altering the balance between Bcl-2 and Bax protein expressions and decreased survivin and pro-caspase-3 expressions.
authors.forename: Yaning
authors.initials: Y
authors.lastname: Hao
authors.forename: Fei
authors.initials: F
authors.lastname: Zhao
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Luo
authors.forename: Mei
authors.initials: M
authors.lastname: Zhang
authors.forename: Shasha
authors.initials: S
authors.lastname: Li
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D045786:Diterpenes, Kaurane / Q000494:pharmacology*; D006131:Growth Inhibitors / Q000494:pharmacology*; D006801:Humans; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D045786:Diterpenes, Kaurane; D006131:Growth Inhibitors; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C011959:oridonin; D053148:Caspase 3