title: [The effects of carotenoids on the proliferation of human breast cancer cell and gene expression of bcl-2].
abstract: OBJECTIVE
  To investigate the effects of various carotenoids on the proliferation, cell cycle, apoptosis and expression of bcl-2 gene in breast cancer cell MCF-7.
  
  
  METHODS
  Time and dose effects of individual carotenoids were detected using the MTT assay. The effects of individual carotenoids on cell cycle and the apoptosis were observed by flow cytometry. The expression of bcl-2 mRNA gene was detected using the RT-PCR method.
  
  
  RESULTS
  All 4 carotenoids tested inhibited the proliferation of MCF-7 cell line, but with different potencies. beta-carotene and lycopene were the most active inhibitors (inhibition rate 88.2% and 87.8%, respectively) followed by zeaxanthin and astaxanthin. All 4 carotenoids did not induce cell apoptosis. Cell cycle progression was blocked at G(2)/M phase with 60 micromol/L lycopene and at G(0)/G(1) phase with 60 micromol/L zeaxanthin dipalmitate. Carotenoids down regulated bcl-2 gene expression.
  
  
  CONCLUSIONS
  Carotenoids could inhibit the proliferation of human beast cancer MCF-7 cell line in vitro and the action of carotenoids may be worked through different pathways.
authors.affiliation: Public Health College of Nanjing Medical University, Nanjing 210029, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Li
authors.forename: Yingming
authors.initials: Y
authors.lastname: Wang
authors.forename: Baoqing
authors.initials: B
authors.lastname: Mo
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D016644:Canthaxanthin / Q000494:pharmacology; D002338:Carotenoids / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects*; D002455:Cell Division / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D000077276:Lycopene; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics*; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D024341:Xanthophylls; D065146:Zeaxanthins; D019207:beta Carotene; D002338:Carotenoids; D016644:Canthaxanthin; C005948:astaxanthine; D000077276:Lycopene