IMIBIO-SL   20937
INSTITUTO MULTIDISCIPLINARIO DE INVESTIGACIONES BIOLOGICAS DE SAN LUIS
Unidad Ejecutora - UE
artículos
Título:
Filamin A Expression Negatively Regulates Sphingosine-1-Phosphate-Induced NF-κB Activation in Melanoma Cells by Inhibition of Akt Signaling
Autor/es:
CAMPOS LUDMILA ESTEFANÍA; RODRIGUEZ YAMILA ISABEL; LEOPOLDINO AM; HAIT NC; LOPEZ BERGAMI PABLO; CASTRO MELINA GABRIELA; SANCHEZ EMILSE; SPIEGEL SARAH; ALVAREZ SERGIO EDUARDO
Revista:
MOLECULAR AND CELLULAR BIOLOGY
Editorial:
AMER SOC MICROBIOLOGY
Referencias:
Lugar: Washington; Año: 2015
ISSN:
0270-7306
Resumen:
Sphingosine-1-phosphate (S1P) is a bioactive lipid mediator that regulates many processes in inflammation and cancer. S1P is a ligand for five G-protein-coupled receptors, S1PR1 to -5, and also has important intracellular actions. Previously, we showed that intracellular S1P is involved in tumor necrosis factor alpha (TNF)-induced NF-κB activation in melanoma cell lines that express filamin A (FLNA). Here, we show that extracellular S1P activates NF-κB only in melanoma cells that lack FLNA. In these cells, S1P, but not TNF, promotes IκB kinase (IKK) and p65 phosphorylation, IκBα degradation, p65 nuclear translocation, and NF-κB reporter activity. NF-κB activation induced by S1P was mediated via S1PR1 and S1PR2. Exogenous S1P enhanced the phosphorylation of protein kinase Cδ (PKCδ), and its downregulation reduced S1P-induced the phosphorylation of IKK and p65. In addition, silencing of Bcl10 also inhibited S1P-induced IKK phosphorylation. Surprisingly, S1P reduced Akt activation in melanoma cells that express FLNA, whereas in the absence of FLNA, high phosphorylation levels of Akt were maintained, enabling S1P-mediated NF-κB signaling. In accord, inhibition of Akt suppressed S1P-mediated IKK and p65 phosphorylation and degradation of IκBα. Hence, these results support a negative role of FLNA in S1P-mediated NF-κB activation in melanoma cells through modulation of Akt.