title: Vitamin D effect on growth and vitamin D metabolizing enzymes in triple-negative breast cancer.
abstract: BACKGROUND
  Triple-negative breast cancer (TNBC) is an aggressive form of breast cancer that disproportionately affects women with darker skin. Epidemiological studies indicate that higher vitamin D levels prevent incidence of TNBC and translate to higher survival rates in those that have TNBC.
  
  
  METHODS
  The growth inhibition effects of two forms of vitamin D were assessed in MCF-7 and three TNBC lines using CellTiter-Glo. Expression of vitamin D-metabolizing enzymes was measured after vitamin D treatment by quantitative reverse transcription polymerase chain reaction (RT-qPCR).
  
  
  RESULTS
  MCF-7 was growth inhibited by vitamin D at high concentrations but the TNBC lines were not. All cell lines demonstrated large increases in CYP24A1 mRNA levels under vitamin D treatment but there was little change in CYP27B1 or VDR mRNA levels.
  
  
  CONCLUSIONS
  These TNBC cell lines are resistant to growth inhibition by vitamin D. This could be due to large inactivation of vitamin D by CYP24A1 or by another mechanism.
authors: University of Michigan-Flint, Department of Chemistry and Biochemistry, Flint, MI, U.S.A.
authors: Sarah E
authors: SE
authors: Richards
authors: University of Michigan-Flint, Department of Chemistry and Biochemistry, Flint, MI, U.S.A.
authors: Kaytie A
authors: KA
authors: Weierstahl
authors: University of Michigan-Flint, Department of Chemistry and Biochemistry, Flint, MI, U.S.A. jkelts@umflint.edu.
authors: Jessica L
authors: JL
authors: Kelts
mesh_terms: D002455:Cell Division / Q000187:drug effects*; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics; D018167:Receptors, Calcitriol / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D064726:Triple Negative Breast Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000473:pathology*; D014807:Vitamin D / Q000378:metabolism / Q000494:pharmacology*; D065668:Vitamin D3 24-Hydroxylase / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D018167:Receptors, Calcitriol; D014807:Vitamin D; C585549:CYP24A1 protein, human; D065668:Vitamin D3 24-Hydroxylase
keywords: 25-hydroxyvitamin D; Breast cancer; CYP24A1; CYP27B1; triple-negative breast cancer; vitamin D; vitamin D receptor