title: [Effect of long-term power frequency electromagnetic field exposure on proliferation and apoptosis of SRA01/04 cells].
abstract: OBJECTIVE
  To investigate the effect of long-term power frequency electromagnetic field (50 Hz) exposure on the proliferation and apoptosis of human lens epithelial cells (SRA01/04 cells).
  
  
  METHODS
  SRA01/04 cells in the exponential growth phase were exposed or sham-exposed to power frequency electromagnetic field (50 Hz, 2.3 mT) for 2 hours per day, 5 days every week. After 11 weeks of exposure, the cells were collected; the cell morphology was observed under a microscope, the cell viability was measured by MTT assay, the cell cycle and apoptosis were examined by flow cytometry, and the protein expression levels of cyclin D and proliferating cell nuclear antigen (PCNA) were determined by western blot.
  
  
  RESULTS
  Compared with the sham-exposed SRA01/04 cells, most exposed cells became rounded and more stereoscopic, and heterochromatin gathered near the nuclear membrane in some exposed cells. The MTT assay showed that the viability of exposed cells was significantly increased compared with that of the sham-exposed cells (P < 0.05). Long-term power frequency electromagnetic field exposure led to significantly increased number of cells in S phase (P < 0.05), and the proliferation index was significantly higher in the exposed cells than in the sham-exposed cells (P < 0.05). There was no significant difference in apoptotic rate between the exposed cells and sham-exposed cells (P > 0.05). The exposed cells had significantly higher protein expression levels of cyclin D and PCNA than the sham-exposed cells (P < 0.05).
  
  
  CONCLUSIONS
  Long-term power frequency electromagnetic field exposure can promote cellular proliferation and change cell cycle in SRA01/04 cells, but it has no marked effect on the apoptosis of SRA01/04 cells.
authors.affiliation: Department of Radiation Medicine, College of Preventive Medicine, Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Guang-zhou
authors.initials: GZ
authors.lastname: An
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Qing-xia
authors.initials: QX
authors.lastname: Hou
authors.forename: Yu-rong
authors.initials: YR
authors.lastname: Li
authors.forename: Da-peng
authors.initials: DP
authors.lastname: Jiang
authors.forename: Guo-zhen
authors.initials: GZ
authors.lastname: Guo
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.forename: Gui-rong
authors.initials: GR
authors.lastname: Ding
mesh_terms: D017209:Apoptosis; D002460:Cell Line; D049109:Cell Proliferation; D019938:Cyclin D1 / Q000378:metabolism; D004574:Electromagnetic Fields / Q000009:adverse effects*; D004781:Environmental Exposure / Q000009:adverse effects; D004847:Epithelial Cells / Q000166:cytology*; D006801:Humans; D007908:Lens, Crystalline / Q000166:cytology; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism
chemical_list: C530104:CCND1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D019938:Cyclin D1