title: Tyrosine 23 Phosphorylation of Annexin A2 Promotes Proliferation, Invasion, and Stat3 Phosphorylation in the Nucleus of Human Breast Cancer SK-BR-3 Cells.
abstract: OBJECTIVE
  To investigate the role of tyrosine 23 (Tyr23) phosphorylation of Annexin A2 (Anxa2) in regulating the proliferation and invasion of human breast cancer SK-BR-3 cells.
  
  
  METHODS
  A panel of lentivirus plasmids expressing Anxa2-wide type (Ana2-WT), Anxa2-Y23A, and Anxa2-Y23D was generated and infected with SK-BR-3 cells. The monoclonal strains were screened. The expression of Anxa2-WT, Anxa2-Y23A, and Anxa2-Y23D was determined by Western blot analysis. The ability of the cells to proliferate was detected through an MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] test. Boyden chamber assays were employed to examine migration and invasion abilities. The interaction between Anxa2 and Stat3 was analyzed by immunoprecipitation analyses. Nucleoprotein and cytosolic protein were extracted from SK-BR-3, Anxa2-WT, Anxa2-Y23A, and Anxa2-Y23D cells to analyze the expression and localization of Stat3 phosphorylation.
  
  
  RESULTS
  The monoclonal strains constitutively expressing Anxa2-WT, Anxa2-Y23A, and Anxa2-Y23D were screened. Both Anxa2-WT and Anxa2-Y23D enhanced the proliferation, migration and invasion abilities of SK-BR-3 cells (P<0.05). Immunoprecipitation analysis revealed that Anxa2 and Stat3 interacted with each other, and the expression of Stat3 phosphorylation in the nucleus was enhanced by Anxa2-Y23D.
  
  
  CONCLUSIONS
  Tyr23 phosphorylation of Anxa2 promotes the proliferation and invasion of human breast cancer SK-BR-3 cells and the phosphorylation of Stat3 in the nucleus.
authors.affiliation: Tianjin Medical University Cancer Institute and Hospital; Key Laboratory of Cancer Prevention and Therapy, Tianjin; Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, Tianjin 300060, China.
authors.forename: Yu-Qing
authors.initials: YQ
authors.lastname: Wang
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.forename: Ran
authors.initials: R
authors.lastname: Tian
authors.forename: Wei
authors.initials: W
authors.lastname: Ji
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Xiu-Mei
authors.initials: XM
authors.lastname: Sun
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhi-Yong
authors.initials: ZY
authors.lastname: Wang
authors.forename: Rui-Fang
authors.initials: RF
authors.lastname: Niu
keywords: Annexin A2; Stat3 transcription factor; mutation; phosphorylation; tyrosine