title: [Temporary acid exposure promotes normal human esophageal epithelial cell proliferation and ERK expression in vitro].
abstract: OBJECTIVE
  To observe the effects of temporary acid exposure on cell proliferation and extracellular signal-regulated protein kinase (ERK) activity in normal human esophageal epithelial cells in vitro.
  
  
  METHODS
  Normal human esophageal epithelial cells cultured in vitro were exposed to acidic media (pH 4.0-6.5) for 3 to 60 min, and the control cells were cultured at pH 7.3. MTT assay and flow cytometry were employed for cell proliferation assessment. The expression of phosphorylated ERK1/2 protein was determined by immunoblotting.
  
  
  RESULTS
  Esophageal epithelial cells with acid exposure for 3 min exhibited a significant increase in cell proliferation, increased number of cells in S phase and enhanced expression of phosphorylated ERK1/2 protein. Acid exposure of the esophageal epithelial cells exceeding 6 min resulted in depressed proliferation and decreased S-phase cells, and cell proliferation induced by acid exposure was abolished by pretreatment with U0126.
  
  
  CONCLUSIONS
  Temporary acid stimulus increases cell proliferation of normal human esophageal epithelial cells in vitro by activating the ERK pathway.
authors.affiliation: Department of Gastroenterology, Second Affiliated Hospital of Xi'an Jiaotong University, Xi'an 710004, China. jiangzhr@21cn.com
authors.forename: Zhi-ru
authors.initials: ZR
authors.lastname: Jiang
authors.forename: Jun
authors.initials: J
authors.lastname: Gong
authors.forename: Zhe
authors.initials: Z
authors.lastname: Qiao
authors.forename: Zhen-ni
authors.initials: ZN
authors.lastname: Zhang
mesh_terms: D000143:Acids / Q000494:pharmacology*; D015153:Blotting, Western; D002070:Butadienes / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D004947:Esophagus / Q000166:cytology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D053547:Keratin-14 / Q000032:analysis; D009570:Nitriles / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects; D013997:Time Factors
chemical_list: D000143:Acids; D002070:Butadienes; D003470:Culture Media; D004791:Enzyme Inhibitors; D053547:Keratin-14; D009570:Nitriles; C113580:U 0126; D048049:Extracellular Signal-Regulated MAP Kinases