title: [Effect of Evn-50 on cell growth and apoptosis in tamoxifen-resistance human breast cancer cell line MCF-7/TAM-R].
abstract: To investigate the effect of Evn-50 extracted from Vitex negundo on human breast cancer cell line MCF-7 and MCF-7/TAM-R cells in vitro.
  
  
  
  MCF-7 and tamoxifen-resistant MCF-7/TAM-R cells were treated with Evn-50,tamoxifen or combination of Evn-50 and tamoxifen. Cell proliferation inhibition rates were determined by MTT assay. The apoptosis rate and the change of cell cycle were detected by PI staining flow cytometry. Protein expression of phospho-MAPK 44/42 (Thr202/Tyr204),MAPK P44/42, phospho-AKT (Ser473) and AKT were detected with Western blotting.
  
  
  
  The viability of MCF-7 cells was decreased in combination group [(28.65 ±11.43)%] and Evn-50 group [(53.02 ±15.14)%] compared with TAM group (P<0.01). The cell viability of MCF-7/TAM-R in combination group [(42.11 ±14.30)%] was significantly lower than that in TAM group [(92.18 ±13.16)%] (P<0.01). The cell apoptosis rate was dependent on the time of treatment in all groups,the effects on apoptosis and G2/M phase cells were most prominent at 72 h (P<0.01). Western blotting revealed that protein levels of phosphorylated AKT and p-MAPK44/42 decreased,while the expression of total AKT and MAPK44/42 was stable. In MCF-7/TAM-R cells,the expression of phosphorylation of AKT and MAPK44/42 protein was not changed in Evn-50 or TAM alone group,but significantly inhibited in the combination group at 72 h.
  
  
  
  Evn-50 can inhibit cell growth and induce apoptosis in MCF-7 and MCF-7/TAM-R cells,it can reverse tamoxifen-resistance of MCF-7/TAM-R cells.The mechanisms may be related to the down-regulation of phosphorylated ERK1/2 in MAPK signal pathway and phosphorylated AKT in AKT signal pathway.
authors.affiliation: Department of Breast Surgery, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Hui-yong
authors.initials: HY
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Zhou
authors.forename: Fang
authors.initials: F
authors.lastname: Wan
authors.forename: Li-feng
authors.initials: LF
authors.lastname: Dong
authors.forename: Feng
authors.initials: F
authors.lastname: Zhang
authors.forename: Yi-ke
authors.initials: YK
authors.lastname: Wang
authors.forename: Fang-fang
authors.initials: FF
authors.lastname: Chen
authors.forename: Yi-ding
authors.initials: YD
authors.lastname: Chen
mesh_terms: D017209:Apoptosis / Q000187:drug effects*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology*; D002453:Cell Cycle / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology*; D005260:Female; D006801:Humans; D061986:MCF-7 Cells; D010766:Phosphorylation; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013629:Tamoxifen / Q000627:therapeutic use; D020950:Vitex / Q000737:chemistry
chemical_list: D004365:Drugs, Chinese Herbal; D013629:Tamoxifen; D051057:Proto-Oncogene Proteins c-akt