title: 1Alpha,25-dihydroxyvitamin D3-mediated stimulation of steroid sulphatase activity in myeloid leukaemic cell lines requires VDRnuc-mediated activation of the RAS/RAF/ERK-MAP kinase signalling pathway.
abstract: 1Alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)(2)D(3)) stimulates the activity of steroid sulphatase (STS) in myeloid cells [Hughes et al., 2001, 2005]. This was attenuated by inhibitors of phospholipase D (PLD) (n-butanol, 2,3-diphosphoglyceric acid, C(2)-ceramide) and phosphatidate phosphohydrolase (PAP) (propranolol and chlorpromazine), but was unaffected by inhibitors of phospholipase C. The 1alpha,25(OH)(2)D(3)-induced STS activity was also attenuated by inhibitors of protein kinase Calpha and protein kinase Cdelta (Go 6976, HBDDE and rottlerin), but not by an inhibitor of protein kinase Cbeta (LY379196). Additionally, 1alpha,25(OH)(2)D(3)-induced STS activity was attenuated by inhibitors of RAS (manumycin A), RAF (GW5074), MEK (PD098059 and U1026) and JNK (SP600125), but not p38 (PD169316). 1alpha,25(OH)(2)D(3) produced a rapid and long lasting stimulation of the ERK-MAP kinase signalling cascade in HL60 myeloid leukaemic cells. This 'non-genomic' effect of 1alpha,25(OH)(2)D(3) blocked by pharmacological antagonists of nuclear vitamin D receptors (VDR(nuc)) and does not appear to require hetero-dimerisation with the retinoid-X receptor (RXR). Inhibitors of the Src tyrosine kinase (PP1), RAS (manumycin A), RAS-RAF interactions (sulindac sulphide and RAS inhibitory peptide), RAF (GW5074 or chloroquine), and protein kinase Calpha (HBDDE) abrogated the 1alpha,25(OH)(2)D(3)-stimulated increase in ERK-MAP kinase activity. Taken together, these results show that 1alpha,25(OH)(2)D(3)/VDR(nuc) activation of the RAS/RAF/ERK-MAP kinase signalling pathway plays an important role in augmenting STS activity in human myeloid leukaemic cell lines.
authors.affiliation: Division of Immunity and Infection, The Medical School, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom. P.J.Hughes@bham.ac.uk
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Hughes
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Brown
mesh_terms: D020013:Calcium Signaling; D045744:Cell Line, Tumor; D004789:Enzyme Activation / Q000187:drug effects; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D006801:Humans; D007951:Leukemia, Myeloid / Q000201:enzymology / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects*; D010739:Phospholipase D / Q000378:metabolism; D051571:Protein Kinase C-alpha / Q000037:antagonists & inhibitors; D051745:Protein Kinase C-delta / Q000037:antagonists & inhibitors; D018167:Receptors, Calcitriol / Q000378:metabolism*; D015398:Signal Transduction; D043266:Steryl-Sulfatase / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D010738:Type C Phospholipases / Q000378:metabolism; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000494:pharmacology; D048490:raf Kinases / Q000378:metabolism*; D018631:ras Proteins / Q000378:metabolism*; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D018167:Receptors, Calcitriol; C118756:dihydroxy-vitamin D3; D014807:Vitamin D; D019061:src-Family Kinases; D048490:raf Kinases; D051571:Protein Kinase C-alpha; D051745:Protein Kinase C-delta; D048049:Extracellular Signal-Regulated MAP Kinases; D010738:Type C Phospholipases; D010739:Phospholipase D; D043266:Steryl-Sulfatase; D018631:ras Proteins