title: 1α, 25-Dihydroxyvitamin D regulates hypoxia-inducible factor-1α in untransformed and Harvey-ras transfected breast epithelial cells.
abstract: The purpose of this study was to determine the mechanism by which 1α, 25-dihydroxyvitamin D (1,25(OH)(2)D) alters hypoxia-inducible factor-1α (HIF-1α) protein in untransformed and Harvey-ras (H-ras) oncogene transfected MCF10A breast epithelial cells. Treatment with 1,25(OH)(2)D (10nM) increased both mRNA (2.55±0.6-fold vs. vehicle, p=0.03) and protein levels (2.37±0.3-fold vs. vehicle, p<0.0001) of HIF-1α in MCF10A cells in 12h, which remained elevated at 24h. However, in H-ras transfected MCF10A cells, 1,25(OH)(2)D treatment increased HIF-1α protein level (2.08±0.38-fold vs. vehicle, p=0.05) at 12h, with no change in mRNA level and HIF-1α protein level returned to baseline after 24h. A transcription inhibitor prevented the 1,25(OH)(2)D induction of HIF-1α protein and mRNA levels in MCF10A cells, but failed to alter the induction of HIF-1α protein level in H-ras transfected MCF10A cells. On the other hand, inhibition of proteasomal degradation prevented the 1,25(OH)(2)D-induced HIF-1α protein level in H-ras transfected MCF10A but not in MCF10A cells. These results support that 1,25(OH)(2)D regulates HIF-1α protein level via transcriptional regulation in MCF10A cells in contrast to through proteosomal degradation with the presence of H-ras oncogene in MCF10A cells.
authors.affiliation: Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47906, USA. Jiang19@purdue.edu
authors.forename: Yan
authors.initials: Y
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Zheng
authors.forename: Dorothy
authors.initials: D
authors.lastname: Teegarden
mesh_terms: D015153:Blotting, Western; D002117:Calcitriol / Q000494:pharmacology*; D002460:Cell Line; D002461:Cell Line, Transformed; D002472:Cell Transformation, Viral / Q000235:genetics*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000235:genetics* / Q000378:metabolism; D007976:Leupeptins / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D018167:Receptors, Calcitriol / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection; D014815:Vitamins / Q000494:pharmacology
chemical_list: D015853:Cysteine Proteinase Inhibitors; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007976:Leupeptins; D011500:Protein Synthesis Inhibitors; D018167:Receptors, Calcitriol; D014815:Vitamins; D003609:Dactinomycin; D002117:Calcitriol; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde