title: [Synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells and its related mechanism].
abstract: OBJECTIVE
  To investigate the synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells and the down-regulating effect of curcumin on the Keapl-Nrf2 pathway, a well recognized anti-drug pathway in almost drugged tumor cells.
  
  
  METHODS
  T24 cells were cultured and treated with increasing concentrations of curcumin(5 ,10 and 20 µmol/mL) combined with cisplatin(30 µg/mL) for 24 hours. The inhibitory effects on T24 cells were tested with MTI colorimetric assay. Nuclear Nrf2 and Keapl , cytoplasmic Keapl and two typical phase II enzymes (GSTP1 and NQOl) were checked with Western blotting.
  
  
  RESULTS
  The proliferation of T24 cells was significantly inhibited by different concentrations of curcumin combined with cisplatin. After the treatment with different concentrations of curcumin, Nuclear Nrf2 was decreased but Keapl was increased, and GSTP1 and NQO1 were decreased.
  
  
  CONCLUSIONS
  Synergism inhibition of curcumin combined with cisplatin on T24 bladder carcinoma cells is observed in this research. The Keapl-Nrf2 pathway in T24 cells is down-regulated by curcumin. The expression of typical phase I enzymes (GSTP1 and NQO1) mediated by Nrf2 are decreased by curcumin. The sensitivity of tumor cells to chemotherapeutic drugs is then enhanced. These may be the mechanism of synergism effect of curcumin combined with cisplatin.
authors.forename: Shao-nan
authors.initials: SN
authors.lastname: Zhang
authors.forename: Qun
authors.initials: Q
authors.lastname: Yong
authors.forename: Xin-li
authors.initials: XL
authors.lastname: Wu
authors.forename: Xiao-ping
authors.initials: XP
authors.lastname: Liu
mesh_terms: D045744:Cell Line, Tumor / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D003474:Curcumin / Q000494:pharmacology*; D004357:Drug Synergism; D051549:Glutathione S-Transferase pi / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D000072019:Kelch-Like ECH-Associated Protein 1; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D001749:Urinary Bladder Neoplasms / Q000378:metabolism*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C431364:KEAP1 protein, human; D000072019:Kelch-Like ECH-Associated Protein 1; D051267:NF-E2-Related Factor 2; C495635:NFE2L2 protein, human; D016660:NAD(P)H Dehydrogenase (Quinone); C447479:NQO1 protein, human; C496556:GSTP1 protein, human; D051549:Glutathione S-Transferase pi; D003474:Curcumin; D002945:Cisplatin