title: The vitamin D receptor agonist elocalcitol inhibits IL-8-dependent benign prostatic hyperplasia stromal cell proliferation and inflammatory response by targeting the RhoA/Rho kinase and NF-kappaB pathways.
abstract: BACKGROUND
  Benign prostatic hyperplasia (BPH) is characterized by an important inflammatory component. Stimulation of human prostate stromal cells from BPH tissues with proinflammatory cytokines leads to secretion of IL-8, a chemokine involved in BPH pathogenesis. The vitamin D receptor (VDR) agonist elocalcitol can arrest prostate growth in BPH patients, but its mechanism of action in this pathology is still incompletely understood.
  
  
  METHODS
  IL-8 levels were measured by real-time RT-PCR and ELISA. NF-kappaB translocation and COX-2 expression were evaluated by confocal microscopy. RhoA and Rho-kinase (ROCK) gene expression and functional activity were studied by real-time RT-PCR, immuno-kinase assays, Western blot analysis, confocal microscopy, and cell invasion.
  
  
  RESULTS
  Stimulation of BPH cells with IL-8 activates the calcium-sensitizing RhoA/ROCK pathway, as demonstrated by the increased membrane translocation of RhoA and by phosphorylation of the ROCK substrate myosin phosphatase target subunit 1 (MYPT-1). In agreement with these data, C3 exoenzyme, a selective RhoA inhibitor, inhibits IL-8-induced invasion of BPH cells. The VDR agonist elocalcitol significantly inhibits IL-8 production by BPH cells stimulated with inflammatory cytokines, and IL-8-induced proliferation of BPH cells. In addition, elocalcitol inhibits IL-8-induced membrane translocation of RhoA and MYPT-1 phosphorylation in BPH cells, and inhibits dose-dependently their IL-8-dependent invasion. The inhibition induced by elocalcitol of IL-8 production by BPH cells is accompanied by decreased COX-2 expression and PGE(2) production and by arrest of NF-kappaB p65 nuclear translocation, associated with inhibition of the RhoA/ROCK pathway.
  
  
  CONCLUSIONS
  These data provide a mechanistic explanation for the anti-proliferative and anti-inflammatory properties of elocalcitol in BPH cells.
authors.affiliation: BioXell, Milan, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Penna
authors.forename: Benedetta
authors.initials: B
authors.lastname: Fibbi
authors.forename: Susana
authors.initials: S
authors.lastname: Amuchastegui
authors.forename: Elisa
authors.initials: E
authors.lastname: Corsiero
authors.forename: Gilles
authors.initials: G
authors.lastname: Laverny
authors.forename: Enrico
authors.initials: E
authors.lastname: Silvestrini
authors.forename: Aravinda
authors.initials: A
authors.lastname: Chavalmane
authors.forename: Annamaria
authors.initials: A
authors.lastname: Morelli
authors.forename: Erica
authors.initials: E
authors.lastname: Sarchielli
authors.forename: Gabriella Barbara
authors.initials: GB
authors.lastname: Vannelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Gacci
authors.forename: Enrico
authors.initials: E
authors.lastname: Colli
authors.forename: Mario
authors.initials: M
authors.lastname: Maggi
authors.forename: Luciano
authors.initials: L
authors.lastname: Adorini
mesh_terms: D002117:Calcitriol / Q000031:analogs & derivatives* / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D051546:Cyclooxygenase 2 / Q000378:metabolism; D015232:Dinoprostone / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000473:pathology; D007371:Interferon-gamma / Q000494:pharmacology; D020381:Interleukin-17 / Q000494:pharmacology; D016209:Interleukin-8 / Q000378:metabolism*; D008297:Male; D016328:NF-kappa B / Q000378:metabolism*; D011470:Prostatic Hyperplasia / Q000378:metabolism / Q000473:pathology*; D018167:Receptors, Calcitriol / Q000819:agonists; D015398:Signal Transduction / Q000187:drug effects; D017154:Stromal Cells / Q000378:metabolism / Q000473:pathology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000378:metabolism*; D020742:rhoA GTP-Binding Protein / Q000378:metabolism*
chemical_list: C487049:BXL628; D020381:Interleukin-17; D016209:Interleukin-8; D016328:NF-kappa B; D018167:Receptors, Calcitriol; D014409:Tumor Necrosis Factor-alpha; D007371:Interferon-gamma; D051546:Cyclooxygenase 2; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D002117:Calcitriol; D015232:Dinoprostone