title: [Relationship between BH3 mimetic S1 and expression of BCL-2 family members in acute myeloid leukemia].
abstract: OBJECTIVE
  This study was to investigate the molecular biomarkers of apoptosis induced by BH3 mimetic S1 in human primary AML cells.
  
  
  METHODS
  Mononuclear cells were isolated from 27 newly diagnosed AML samples. Apoptosis was analyzed by flow cytometry. IC(50) value of S1 on these samples was determined by XTT assay. The expression level of BCL-2 family members and phosphorylated BCL-2 were assessed by Western blot with subsequent semi-quantitatively densitometric analysis. XTT assay was performed to determine the cell viability of the combined use of S1 and MEK/ERK inhibitor PD98059. The interactions between BCL-2 and pro-apoptosis proteins were tested by co-immunoprecipitation.
  
  
  RESULTS
  The flow-cytometry detection showed that S1 induced the apoptosis of primary AML cells. Based on the responses, 27 primary samples could be classified into three groups: (1) a sensitive group (12 of 27 cases) with IC(50)<14 µmol/L, (2) an intermediate group (8 of 27 cases) with IC(50) of 14-30 µmol/L and (3) a resistant group (7 of 27 cases) with IC(50)>30 µmol/L. The ratio of pBCL-2/(BCL-2+MCL-1) showed a good linear correlation with the IC(50) values. (R(2) = 0.71, P < 0.0001). PD98059 suppressed BCL-2 phosphorylation. When PD98059 suppressed BCL-2 phosphorylation, the apoptotic rate of drug-resistant cells induced by S1 increased from 9.8% to 64.5% (combination index, CI = 0.4), accompanied by more dissociation of BCL-2 heterodimers.
  
  
  CONCLUSIONS
  The combination of S1 with PD98059 decrease pBCL-2 level of AML patients and inhibits of the anti-apoptotic function of BCL-2 through enhancing the dissociation of BCL-2 heterodimers.
authors: Department of Hematology, The Second Affiliated Hospital of Dalian Medical University, Dalian 116023, Liaoning Province, China.
authors: Xiao-Bo
authors: XB
authors: Wang
authors: Complex Laboratory of Clinical Examination, Laboratory Medical College, Dalian Medical University, Dalian 116044, Liaoning Province, China.
authors: Ming
authors: M
authors: Shi
authors: Department of Hematology, The Second Affiliated Hospital of Dalian Medical University, Dalian 116023, Liaoning Province, China.
authors: Li-Jun
authors: LJ
authors: Mu
authors: Department of Hematology, The Second Affiliated Hospital of Dalian Medical University, Dalian 116023, Liaoning Province, China.
authors: Jian
authors: J
authors: Sun
authors: Department of Hematology, The Second Affiliated Hospital of Dalian Medical University, Dalian 116023, Liaoning Province, China.
authors: Wei-Ping
authors: WP
authors: Li
authors: Department of Hematology, The Second Affiliated Hospital of Dalian Medical University, Dalian 116023, Liaoning Province, China. E-mail:beijing2008willwin@163.com.
authors: Zu-Guang
authors: ZG
authors: Xue
mesh_terms: D000964:Antimetabolites, Antineoplastic; D017209:Apoptosis; D045744:Cell Line, Tumor; D004338:Drug Combinations; D006801:Humans; D015470:Leukemia, Myeloid, Acute; D018716:Molecular Mimicry; D010094:Oxonic Acid; D010766:Phosphorylation; D019253:Proto-Oncogene Proteins c-bcl-2; D005641:Tegafur
chemical_list: D000964:Antimetabolites, Antineoplastic; D004338:Drug Combinations; D019253:Proto-Oncogene Proteins c-bcl-2; C079198:S 1 (combination); D005641:Tegafur; D010094:Oxonic Acid