title: [Influence of arsenic trioxide and daunorubicin on the expression of annexin II and fibrinolytic activity in NB4 cells].
abstract: OBJECTIVE
  To study the expression of annexin II (AnnII) and the fibrinolytic activity in NB4 cells and their alterations in the presence of arsenic trioxide (ATO) and daunorubicin (DNR).
  
  
  METHODS
  Leukemia cell line NB4 was treated with ATO or DNR for 24 ∼ 72 h. Cell surface expression of AnnII and its mRNA were analysed by flow cytometry and real time PCR, respectively, the fibrinolytic activity by chromogenic assay.
  
  
  RESULTS
  Compared with other acute leukemia cell lines, the expression of AnnII on untreated NB4 cells was relatively higher. The AnnII positive cell rates on NB4, HL-60, K562, and A3 cells were (94.5 ± 1.6)%, (40.1 ± 2.1)%, (36.3 ± 1.5)% and (11.8 ± 2.5)%, respectively. The fibrinolytic activity of NB4 cells was the greatest with a A value of 0.68 ± 0.02. The fibrinolytic activity of NB4 cells was obviously decreased by ATO, DNR or monoclonal antibody against AnnII, being decreased by 60.4%, 35.8% and 26.0% of the pretreatment level, respectively. The expressions of AnnII and its mRNA in NB4 cells were decreased dramatically after ATO and DNR treated for 48 h. Annexin II positive cells rate were (55.46 ± 4.72)% and (27.00 ± 6.18)%, respectively.
  
  
  CONCLUSIONS
  NB4 cells have strong ability to enhance the catalytic efficiency of the t-PA-dependent plasminogen activation and AnnII on the cell membrane contributes to this activity. Its high fibrinolytic activity can be corrected by ATO and DNR through down-regulating AnnII.
authors.affiliation: Jiangsu Institute of Hematology, Key Laboratory of Thrombosis and Hemostasis, Ministry of Health, The First Affiliated Hospital of Soochow University, Suzhou 215006, China.
authors.forename: Yan-Hui
authors.initials: YH
authors.lastname: Liu
authors.forename: Zhao-Yue
authors.initials: ZY
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Dai
authors.forename: Wen-Hong
authors.initials: WH
authors.lastname: Shen
authors.forename: Jian-Nong
authors.initials: JN
authors.lastname: Cen
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Chang-Geng
authors.initials: CG
authors.lastname: Ruan
mesh_terms: D017306:Annexin A2; D017209:Apoptosis; D003630:Daunorubicin; D018922:HL-60 Cells; D006801:Humans; D007938:Leukemia / Q000378:metabolism
chemical_list: D017306:Annexin A2; D003630:Daunorubicin