title: Activation of the BRCA1/Chk1/p53/p21(Cip1/Waf1) pathway by nitric oxide and cell cycle arrest in human neuroblastoma NB69 cells.
abstract: Nitric oxide (NO) works as a bi-modal effector of cell proliferation, inducing either the increase or decrease of cell growth when cells are exposed, respectively, to low or high NO concentrations. To get further insight into the action of NO, we tested the effect of short- and long-lived NO donors on the control of the cell cycle in human neuroblastoma NB69 cells. We demonstrated that long-time exposure of cells to NO not only decreased the expression and/or the phosphorylation of elements involved in the control of the G(1)/S transition, such as the transcriptional repressor pRb and cyclin D1, but also down-regulated systems controlling the S and G(2)/M phases, such as the phosphorylation of Cdk1(cdc2) and the expression of cyclins A and B1. Increasing concentrations of NO also induced a biphasic effect on the expression of cyclins D1, A and B1, while this effect was less pronounced for cyclin E expression, but the levels of mRNAs of those cyclins changed in a distinct and complex manner. NO also changed the phosphorylation pattern of cyclin E and decreased the levels of phospho-cyclins D1 and B1. Moreover, NO decreased the expression of the Cdk inhibitors p16(Ink4a) and p19(Ink4d), without affecting p27(Kip1). In contrast, NO induced a biphasic effect on p21(Cip1/Waf1) expression. The BRCA1/Chk1/p53 pathway mediated the upregulation of p21(Cip1/Waf1). We also demonstrated that the NO-mediated up-regulation of p21(Cip1/Waf1) was inversely correlated with the activation status of the p38MAPK pathway.
authors.affiliation: Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain.
authors.forename: Marlies
authors.initials: M
authors.lastname: Van de Wouwer
authors.forename: Célia
authors.initials: C
authors.lastname: Couzinié
authors.forename: Miguel
authors.initials: M
authors.lastname: Serrano-Palero
authors.forename: Oscar
authors.initials: O
authors.lastname: González-Fernández
authors.forename: Clara
authors.initials: C
authors.lastname: Galmés-Varela
authors.forename: Paula
authors.initials: P
authors.lastname: Menéndez-Antolí
authors.forename: Laura
authors.initials: L
authors.lastname: Grau
authors.forename: Antonio
authors.initials: A
authors.lastname: Villalobo
mesh_terms: D019313:BRCA1 Protein / Q000378:metabolism*; D059447:Cell Cycle Checkpoints / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor; D000071877:Checkpoint Kinase 1; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D016213:Cyclins / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006801:Humans; D007093:Imidazoles / Q000494:pharmacology; D009447:Neuroblastoma / Q000378:metabolism* / Q000473:pathology; D009569:Nitric Oxide / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000378:metabolism*; D011725:Pyridines / Q000494:pharmacology; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D019313:BRCA1 Protein; C492913:BRCA1 protein, human; C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016213:Cyclins; D004791:Enzyme Inhibitors; D007093:Imidazoles; D011725:Pyridines; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D009569:Nitric Oxide; D011494:Protein Kinases; C000605867:CHEK1 protein, human; D000071877:Checkpoint Kinase 1; D048051:p38 Mitogen-Activated Protein Kinases; C090942:4-(4-fluorophenyl)-2-(4-hydroxyphenyl)-5-(4-pyridyl)imidazole