title: Effects of cyclopamine on the biological characteristics of human breast cancer MCF-7 cell line and its mechanism.
abstract: OBJECTIVE
  To observe the effects of cyclopamine on the biological characteristics of human breast cancer MCF-7 cell line and explore its mechanism.
  
  
  METHODS
  After human breast cancer MCF-7 cells were treated with different-concentration cyclopamine for different periods, MTT assay was used to detect the inhibitory effect of cyclopamine on MCF-7 cell proliferation, flow cytometry was used to determine the distribution of MCF-7 cell cycle and the effect of cyclopamine on MCF-7 apoptosis, and Western blot was used to measure the protein levels of cyclins D1 and p21 in MCF-7 cells.
  
  
  RESULTS
  In certain range, MCF-7 cell proliferation was inhibited by cyclopamine in a dose- and time-dependent manner, and the optimal inhibiting concentration was ten µmol/L and the optimal action time at 48 hours. With the time prolongation of cyclopamine action, the cells in G0/G1 phase were significantly increased, but the cells in S phase were significantly decreased (compared with blank control group, allp < 0.05). With the time prolongation of cyclopamine action, apoptosis rate of MCF-7 cells was also significantly increased (compared with blank control group, allp < 0.05). The level of cyclin D1 of MCF-7 cells was decreased, but cyclin p21 was increased (compared with blank control group, all p < 0.05).
  
  
  CONCLUSIONS
  Cyclopamine inhibits MCF-7 cell proliferation via arresting MCF-7 cell transformation from G1 phase to S phase. This may be associated with the expressions of Hedgehog (Hh) signaling pathway-related cyclins.
authors.forename: D M
authors.initials: DM
authors.lastname: Zhu
authors.forename: W L
authors.initials: WL
authors.lastname: Xue
authors.forename: W
authors.initials: W
authors.lastname: Tao
authors.forename: J C
authors.initials: JC
authors.lastname: Li
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D019938:Cyclin D1 / Q000032:analysis; D004305:Dose-Response Relationship, Drug; D005260:Female; D005434:Flow Cytometry; D053823:Hedgehog Proteins / Q000037:antagonists & inhibitors / Q000502:physiology; D006801:Humans; D061986:MCF-7 Cells; D014704:Veratrum Alkaloids / Q000494:pharmacology*
chemical_list: C530104:CCND1 protein, human; D053823:Hedgehog Proteins; D014704:Veratrum Alkaloids; D019938:Cyclin D1; C000541:cyclopamine