title: New signalling pathway involved in the anti-proliferative action of vitamin D₃ and its analogues in human neuroblastoma cells. A role for ceramide kinase.
abstract: 1α,25-Dihydroxyvitamin D3 (1,25(OH)₂D₃), a crucial regulator of calcium/phosphorus homeostasis, has important physiological effects on growth and differentiation in a variety of malignant and non-malignant cells. Synthetic structural hormone analogues, with lower hypercalcemic side effects, are currently under clinical investigation. Sphingolipids appear to be crucial bioactive factors in the control of the cell fate: the phosphorylated forms, sphingosine-1-phosphate (S1P) and ceramide-1-phosphate (C1P), are mitogenic factors, whereas sphingosine and ceramide (Cer) usually act as pro-apoptotic agents. Although many studies correlate S1P function to impaired cell growth, the relevance of C1P/Cer system and its involvement in neuroblastoma cells remain to be clarified. Here, we demonstrated the anti-proliferative effect of 1,25(OH)₂D₃ as well as of its structural analogues, ZK156979 and ZK191784, in human SH-SY5Y cells, as judged by [³H]thymidine incorporation, cell growth and evaluation of active ERK1/2 levels. The inhibition of ceramide kinase (CerK), the enzyme responsible for C1P synthesis, by specific gene silencing or pharmacological inhibition, drastically reduced cell proliferation. 1,25(OH)₂D₃ and ZK191784 treatment induced a significant decrease in CerK expression and C1P content, and an increase of Cer. Notably, the treatment of SH-SY5Y cells with ZK159222, antagonist of 1,25(OH)₂D₃ receptor, trichostatin A, inhibitor of histone deacetylases, and COUP-TFI-siRNA prevented the decrease of CerK expression elicited by 1,25(OH)₂D₃ supporting the involvement of VDR/COUP-TFI/histone deacetylase complex in CerK regulation. Altogether, these findings provide the first evidence that CerK/C1P axis acts as molecular effector of the anti-proliferative action of 1,25(OH)₂D₃ and its analogues, thereby representing a new possible target for anti-cancer therapy of human neuroblastoma.
authors.affiliation: Department of Biochemical Sciences, University of Florence, Viale GB Morgagni 50, 50134 Firenze, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Bini
authors.forename: Alessia
authors.initials: A
authors.lastname: Frati
authors.forename: Mercedes
authors.initials: M
authors.lastname: Garcia-Gil
authors.forename: Chiara
authors.initials: C
authors.lastname: Battistini
authors.forename: Maria
authors.initials: M
authors.lastname: Granado
authors.forename: Maria
authors.initials: M
authors.lastname: Martinesi
authors.forename: Marco
authors.initials: M
authors.lastname: Mainardi
authors.forename: Eleonora
authors.initials: E
authors.lastname: Vannini
authors.forename: Federico
authors.initials: F
authors.lastname: Luzzati
authors.forename: Matteo
authors.initials: M
authors.lastname: Caleo
authors.forename: Paolo
authors.initials: P
authors.lastname: Peretto
authors.forename: Antonio
authors.initials: A
authors.lastname: Gomez-Muñoz
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Meacci
mesh_terms: D000970:Antineoplastic Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002117:Calcitriol / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000378:metabolism* / Q000494:pharmacology; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002518:Ceramides / Q000378:metabolism; D015507:Drugs, Investigational / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020868:Gene Silencing; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology; D006801:Humans; D058990:Molecular Targeted Therapy; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009447:Neuroblastoma / Q000188:drug therapy / Q000201:enzymology / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering; D018167:Receptors, Calcitriol / Q000037:antagonists & inhibitors; D015398:Signal Transduction / Q000187:drug effects; D014807:Vitamin D / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: C503158:22-ene-25-oxavitamin D; D000970:Antineoplastic Agents; D002518:Ceramides; D015507:Drugs, Investigational; D004791:Enzyme Inhibitors; D056572:Histone Deacetylase Inhibitors; D009363:Neoplasm Proteins; D034741:RNA, Small Interfering; D018167:Receptors, Calcitriol; C470666:ZK 191784; C410228:ZK159222; C065576:ceramide 1-phosphate; D014807:Vitamin D; D017853:Phosphotransferases (Alcohol Group Acceptor); C066324:ceramide kinase; D002117:Calcitriol