Docetaxel-induced growth inhibition and apoptosis in androgen independent prostate cancer cells are enhanced by 1alpha,25-dihydroxyvitamin D3

Cancer Lett. 2007 Mar 8;247(1):122-9. doi: 10.1016/j.canlet.2006.03.025. Epub 2006 Apr 27.


Pre-treatment with high-dose 1alpha,25-dihydroxyvitamin D(3) (1,25-VD) enhanced the antitumor activity of docetaxel in the androgen-independent prostate cancer cell line, PC-3. The effect manifested as an increasing population of apoptotic cells and amount of pro-apoptotic protein, Bax, under combined treatment compared with single treatment of either 1,25-VD or docetaxel alone. We further demonstrated that pre-treatment with 1,25-VD reduced the expression of multidrug resistance-associated protein-1 at both the mRNA and protein levels. This suggests pre-treatment with 1,25-VD can potentiate cytotoxicity of docetaxel in PC-3 due to 1,25-VD reducing multidrug resistance-associated protein-1 expression.

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / metabolism
  • Androgens / pharmacology
  • Apoptosis / drug effects
  • Calcitriol / pharmacology*
  • Cell Proliferation / drug effects
  • Docetaxel
  • Drug Synergism
  • Humans
  • Male
  • Prostatic Neoplasms / drug therapy*
  • Taxoids / pharmacology*
  • Tumor Cells, Cultured
  • bcl-2-Associated X Protein / metabolism


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Androgens
  • BAX protein, human
  • Taxoids
  • bcl-2-Associated X Protein
  • Docetaxel
  • Calcitriol