title: [Synergistic inhibitory effect of STI571 in combination with arsenic trioxide on a multidrug-resistant leukemia cell line expressing bcr-abl].
abstract: OBJECTIVE
  To study the synergistic effect of STI571, an inhibitor of tyrosine kinase in combination with arsenic trioxide (As(2)O(3)) on a multidrug-resistant leukemia cell line expressing bcr-abl.
  
  
  METHODS
  The cytotoxic effect of STI571 alone or in combination with different concentrations of As(2)O(3) on both bcr-abl and mdr1 positive leukemia cell line K562-n/VCR was detected by MTT method.
  
  
  RESULTS
  The cytotoxic effect of STI571 (1 micromol/L) combined with As(2)O(3) at concentrations 10(-5), 10(-6), 10(-7), 10(-8) mol/L (IC(50) 0.155 micromol/L) on K562-n/VCR cells was significantly higher than that of As(2)O(3) alone (IC(50) 1.879 micromol/L). The synergistic interaction on K562-n/VCR cells increased the cytotoxic effect by 12.1-fold.
  
  
  CONCLUSIONS
  Combination of STI571 with As(2)O(3) has a synergistic inhibiting effect on leukemia cells expressing bcr-abl and mdr1.
authors.affiliation: Department of Hematology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China. yuhe0628@yahoo.com.cn
authors.forename: Li
authors.initials: L
authors.lastname: Chen
authors.forename: Jian-min
authors.initials: JM
authors.lastname: Wang
authors.forename: Xiao-ping
authors.initials: XP
authors.lastname: Xu
authors.forename: Lei
authors.initials: L
authors.lastname: Gao
authors.forename: Xin-hong
authors.initials: XH
authors.lastname: Fei
authors.forename: Jing-wei
authors.initials: JW
authors.lastname: Lou
authors.forename: Zheng-xia
authors.initials: ZX
authors.lastname: Huang
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D000077237:Arsenic Trioxide; D001152:Arsenicals / Q000494:pharmacology*; D001549:Benzamides; D002470:Cell Survival / Q000187:drug effects*; D018432:Drug Resistance, Multiple; D019008:Drug Resistance, Neoplasm; D004357:Drug Synergism; D019450:Genes, MDR; D016313:Genes, abl; D006801:Humans; D000068877:Imatinib Mesylate; D020128:Inhibitory Concentration 50; D020014:K562 Cells; D010087:Oxides / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors; D011743:Pyrimidines / Q000494:pharmacology*; D014750:Vincristine / Q000494:pharmacology
chemical_list: D000970:Antineoplastic Agents; D001152:Arsenicals; D001549:Benzamides; D010087:Oxides; D010879:Piperazines; D011743:Pyrimidines; D014750:Vincristine; D000068877:Imatinib Mesylate; D011505:Protein-Tyrosine Kinases; D000077237:Arsenic Trioxide