title: [Tetrandrine reversed the resistance of tamoxifen in human breast cancer MCF-7/TAM cells: an experimental research].
abstract: OBJECTIVE
  To study the reverse effect and its mechanism of tetrandrine (Tet) on human breast cancer cells resistant to tamoxifen (MCF-7/TAM).
  
  
  METHODS
  The drug toxicity and the reverse effect of Tet on MCF-7/TAM cells were detected by MTT assay. The effects of multidrug resistance protein 1 (MRP1) gene of Tet on MCF-7iTAM cells were detected by real-time fluorescence quantitative PCR. The changes of MRP1 protein on MCF-7JTAM cells were detected by Western blot.
  
  
  RESULTS
  Tet had a significant reversal of drug resistance on MCF-7/TAM cells. The non-cytotoxic dose (0. 625 microg/mL) reversed the resistance by 2.0 folds. MRP1 was reduced at gene (P <0.05) and protein levels when Tet effected on MCF-7ITAM cells.
  
  
  CONCLUSIONS
  Tet could reverse the drug resistance of MCF-7/TAM cells, and the reverse mechanism may be related to down-regulating MRP1 expression.
authors.affiliation: Department of hematologic Neoplasms, Dongzhimen Hospital, Beijing University of Chinese Medicine, Beijing 100700, China
authors.forename: Hai-yan
authors.initials: HY
authors.lastname: Chen
authors.forename: Xin-yi
authors.initials: XY
authors.lastname: Chen
mesh_terms: D044182:Benzylisoquinolines / Q000494:pharmacology*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects* / Q000235:genetics; D005260:Female; D006801:Humans; D061986:MCF-7 Cells / Q000187:drug effects; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism; D013629:Tamoxifen / Q000494:pharmacology
chemical_list: D044182:Benzylisoquinolines; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D013629:Tamoxifen; C009438:tetrandrine; C421109:multidrug resistance-associated protein 1