title: [Modulating effect of vitamin D3 in vitro on EGFR mRNA expression of human breast cancer cell lines].
abstract: OBJECTIVE
  To assess the modulating effects of vitamin D3, combined with or without tamoxifen, on cell proliferation and EGFR mRNA level of human breast cancer.
  
  
  METHODS
  Two breast cancer cell lines (MCF-7 and ZR-75-1) were treated with various concentrations of vitamin D3, alone or in combination with tamoxifen, for 6 days. Cell proliferation was assessed by MIT uptake and EGFR mRNA level by Northern blot.
  
  
  RESULTS
  10(-10)-10(-7) mol/L vitamin D3 strongly inhibited proliferation of the 2 breast cancer lines, while 10(-9)-10(-7) mol/L tamoxifen stimulated proliferation of MCF-7 cell. The growth inhibitory effect on the 2 cell lines could be augmented and accompanied by a decrease in EGFR mRNA level after combined treatment with IC50 dose of tamoxifen and 10(-10)-10(-9) mol/L vitamin D3.
  
  
  CONCLUSIONS
  Vitamin D3 can be considered as a useful anti-tumor drug in the treatment of breast cancer.
authors.affiliation: Department of Pathology, Shanghai Sixth People's Hospital, Shanghai 200233, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: X
authors.initials: X
authors.lastname: Zhai
authors.forename: Z
authors.initials: Z
authors.lastname: He
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D001943:Breast Neoplasms / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002762:Cholecalciferol / Q000494:pharmacology*; D004347:Drug Interactions; D066246:ErbB Receptors / Q000096:biosynthesis* / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis / Q000187:drug effects; D013629:Tamoxifen / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D018931:Antineoplastic Agents, Hormonal; D012333:RNA, Messenger; D013629:Tamoxifen; D002762:Cholecalciferol; D066246:ErbB Receptors