title: [Down-regulation of AnnexinⅡExpression in NB4 Cells Induced by all-trans Retinoic Acid and Its Mechanisms].
abstract: OBJECTIVE
  To explore effect of all-trans retinoic acid(ATRA) on annexin Ⅱ expression in NB4 cells and to analyze the luciferase activity of annexinⅡ promoter in condition of ATRA-induced treatment.
  
  
  METHODS
  NB4 cells were cultured in vitro, the transcriptional or translational expression levels of Annexin Ⅱ in NB4 cells treated with 1 µmol/L ATRA at different time points were detected by RT-PCR or Western blot respectively. Annexin Ⅱ-promoter was constructed, the recombinant plasmids pGL4.15 -Annexin Ⅱ -promoter were transfected into NB4 cells with electroporation, and after being treated with 1 µmol/L ATRA for 24 hours the luciferase acttivity of Annexin Ⅱ promoter was determined by luciferase activity assay.
  
  
  RESULTS
  The transcriptional expression of Annexin Ⅱ was down-regulated after 48 h. The translation expression of Annexin Ⅱ was slowly weakened after 24 h, and it was seriously reduced after 48 h. Further, Luciferase activity of AnnexinⅡ promoter in NB4 cells treated with 1 µmol/L ATRA was down-regulated, and showed a decreased tendency at indicated time points.
  
  
  CONCLUSIONS
  All-trans retinoic acid can induce the down-regulation of AnnexinⅡ expression on the membrane of NB4 cells, and the activity of Annexin Ⅱpromoter is down-regulated too. This study provide a basis for further study of molecular mechanism.
authors.affiliation: Emergency Intensive Care Unite, The Second Hospital of Lanzhou University, Lanzhou 730030, Gansu Province, China; Hematology Laboratory and Department of Hematology, The Second Hospital Affiliated to Dalian Medical University, Dalian 116027, Liaoning Province, China. E-mail:xrcherry@163.com.
authors.forename: Xiao-Rong
authors.initials: XR
authors.lastname: Dong
authors.affiliation: Hematology Laboratory and Department of Hematology, The Second Hospital Affiliated to Dalian Medical University, Dalian 116027, Liaoning Province, China.
authors.forename: Jin-Song
authors.initials: JS
authors.lastname: Yan
authors.affiliation: Hematology Laboratory and Department of Hematology, The Second Hospital Affiliated to Dalian Medical University, Dalian 116027, Liaoning Province, China.
authors.forename: Fan-Zhi
authors.initials: FZ
authors.lastname: Yan
authors.affiliation: Hematology Laboratory and Department of Hematology, The Second Hospital Affiliated to Dalian Medical University, Dalian 116027, Liaoning Province, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Zhao
mesh_terms: D017306:Annexin A2; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D015536:Down-Regulation; D006801:Humans; D014212:Tretinoin
chemical_list: C472822:ANXA2 protein, human; D017306:Annexin A2; D014212:Tretinoin