title: [Inhibitory effects of exogenous zinc on enzymatic activity of tumor suppressor protein PTEN and possible mechanisms in human airway epithelial cells].
abstract: OBJECTIVE
  To examine the effect of exogenous zinc on enzymatic activity of tumor suppressor PTEN and underlying mechanisms.
  
  
  METHODS
  Human airway epithelial cells (BEAS-2B) were employed as the in vitro model. Enzymatic activity of PTEN was measured using malachite green colorimetric assay and immunoblotting. Moreover, the activity of casein kinase-2 (CK-2), the upstream kinase of PTEN, was determined.
  
  
  RESULTS
  Exposure of BEAS-2B cells to Zn2+ inhibited phosphatase activity of PTEN, as well as PTEN phosphorylation, indicative of PTEN activity (P < 0.05). Under the same experimental condition, Zn2+ stimulation resulted in significant reduction of CK-2 activity (P < 0.05). In addition, CK-2 was shown to induce PTEN phosphorylation (P < 0.05).
  
  
  CONCLUSIONS
  These results suggested that Zn2+ exposure might inhibit PTEN phosphatase activity through inhibition of CK-2 activity in human airway epithelial cells.
authors.affiliation: College of Public Health, Zhengzhou University, Zhengzhou 450001, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Li
authors.forename: Yang
authors.initials: Y
authors.lastname: Lu
authors.forename: Weichao
authors.initials: W
authors.lastname: Yang
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yan
authors.forename: Weidong
authors.initials: W
authors.lastname: Wu
mesh_terms: D001980:Bronchi / Q000166:cytology*; D047390:Casein Kinase II / Q000378:metabolism; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology* / Q000201:enzymology*; D006801:Humans; D051059:PTEN Phosphohydrolase / Q000378:metabolism*; D015032:Zinc / Q000494:pharmacology*
chemical_list: D047390:Casein Kinase II; D051059:PTEN Phosphohydrolase; C494929:PTEN protein, human; D015032:Zinc