title: [Benzo(a)pyrene induced changes of cyclin D1, CDK4 and E2F-1/4 expression in human embryo lung fibroblasts].
abstract: OBJECTIVE
  To establish Benzo (a) pyrene-treated human embryo lung fibroblasts (HELF), which were provided with some characteristics of transformed cells (T-HELF), and observe the changes of cyclin D, CDK4 and E2F-1/4 expression in T-HELF cells.
  
  
  METHODS
  Using 200, 100, 50, 25, 5 and 1 micromol/L B(a)P treated HELF cells for 24 h. Using MTT detected the cytotoxicity of B(a)P. 100,200 micromol/L B(a)P was chosen for the treatment of HELF cells. HELF cells was treated with B(a)P three times. The identification of T-HELF was investigated. Changes of cell cycle and the expression of cyclin D1,CDK4 and E2F-1/4 were checked using the flow cytometer and Western blot analysis.
  
  
  RESULTS
  The survival rate of HELF cells treated with 25-200 micromol/L B(a)P was 78%-80%. 4 w after B(a)P treatment, cells were all dead in 200/mol/L groups. 6 w after 100 micromol/L B(a) P treatment, the morphological changes could be observed. 12 w after treatment, there were colonies of T-HELF cells in soft agar. In T-HELF cells, cyclin D1 expression was higher than normal HELF, and cell cycle progressed through G, to S without serum. There were not significant changes of CDK4 and E2F-1/4 expression in T-HELF cells compared with normal HELF.
  
  
  CONCLUSIONS
  The T-HELF was established. This model provided a potential tool for investigating the molecular mechanism of carcinogenesis of B(a)P. The higher expression of cyclin D1 may contribute to the cell cycle changes of T-HELF cells.
authors.affiliation: National Institute of Occupation Health and Poison Control, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors.forename: Meng
authors.initials: M
authors.lastname: Ye
authors.forename: Bing-ci
authors.initials: BC
authors.lastname: Liu
authors.forename: Hong-ju
authors.initials: HJ
authors.lastname: Du
authors.forename: Bao-rong
authors.initials: BR
authors.lastname: You
mesh_terms: D001564:Benzo(a)pyrene / Q000633:toxicity*; D002273:Carcinogens / Q000633:toxicity; D002453:Cell Cycle / Q000187:drug effects; D019938:Cyclin D1 / Q000378:metabolism*; D051358:Cyclin-Dependent Kinase 4 / Q000378:metabolism*; D050687:E2F1 Transcription Factor / Q000378:metabolism*; D050704:E2F4 Transcription Factor / Q000378:metabolism*; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D008168:Lung / Q000166:cytology* / Q000196:embryology / Q000378:metabolism
chemical_list: C530104:CCND1 protein, human; D002273:Carcinogens; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D050704:E2F4 Transcription Factor; C493762:E2F4 protein, human; D019938:Cyclin D1; D001564:Benzo(a)pyrene; C495900:CDK4 protein, human; D051358:Cyclin-Dependent Kinase 4