title: β-Arrestin 1 is required for endothelin-1-induced NF-κB activation in ovarian cancer cells.
abstract: OBJECTIVE
  In epithelial ovarian cancer (EOC), activation of endothelin-1 (ET-1)/endothelin A receptor (ETAR) signalling is linked to many tumor promoting effects, such as proliferation, angiogenesis, invasion and metastasis. These effects are dependent by the activation of critical signalling pathways, such as MAPK, Akt, and β-catenin, through specific cytosolic and nuclear scaffolding functions of β-arrestin 1 (β-arr1). Here, we have assessed the potential role of ET-1/ETAR in promoting NF-κB signalling in EOC cells through β-arr-1 recruitment.
  
  
  METHODS
  We used cultured HEY EOC cells cultured in the presence or absence of ET-1 and the ETAR antagonist BQ123. The phosphorylation of p65 and Iκ-Bα was evaluated by immunoblotting analysis. The interaction between p65 and β-arr1 was evaluated by immunoprecipitation experiments in nuclear extracts. NF-κB promoter activity was evaluated by transfection with NF-κB-driven luciferase reporter construct. Assessment of the function of β-arr1 was achieved by β-arr1 silencing with shRNA and expression of β-arr1-FLAG expression vector.
  
  
  RESULTS
  In EOC cells, ET-1 promotes the phosphorylation of p65 subunit and the cytoplasmic inhibitor IκB that in turn led to increased NF-κB transcriptional activity. These effects were inhibited by the use of BQ123, as well as by β-arr-1 silencing, suggesting that ET-1 through ETAR promotes the recruitment of β-arr1 to regulate NF-κB signalling. Moreover, the nuclear physical interaction between p65 and β-arr1 indicates a nuclear function of β-arr-1 in ETAR-driven NF-κB transcriptional activity.
  
  
  CONCLUSIONS
  Altogether these findings reveal a previously unrecognized pathway that depends on β-arr1 to sustain NF-κB signalling in response to ETAR activation in ovarian cancer.
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy.
authors: Roberta
authors: R
authors: Cianfrocca
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy.
authors: Piera
authors: P
authors: Tocci
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy.
authors: Elisa
authors: E
authors: Semprucci
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy.
authors: Francesca
authors: F
authors: Spinella
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy.
authors: Valeriana
authors: V
authors: Di Castro
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy. Electronic address: bagnato@ifo.it.
authors: Anna
authors: A
authors: Bagnato
authors: Laboratory of Molecular Pathology, Regina Elena National Cancer Institute, Rome, Italy. Electronic address: rosano@ifo.it.
authors: Laura
authors: L
authors: Rosanò
mesh_terms: D019390:Arrestins / Q000378:metabolism*; D000077216:Carcinoma, Ovarian Epithelial; D045744:Cell Line, Tumor; D019332:Endothelin-1 / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D017930:Genes, Reporter; D006801:Humans; D008954:Models, Biological; D016328:NF-kappa B / Q000378:metabolism*; D009375:Neoplasms, Glandular and Epithelial / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D034741:RNA, Small Interfering / Q000378:metabolism; D044022:Receptor, Endothelin A / Q000235:genetics / Q000378:metabolism; D044023:Receptor, Endothelin B / Q000235:genetics / Q000378:metabolism; D000071559:beta-Arrestin 1; D000071557:beta-Arrestins
chemical_list: C000605253:ARRB1 protein, human; D019390:Arrestins; D019332:Endothelin-1; D016328:NF-kappa B; D034741:RNA, Small Interfering; D044022:Receptor, Endothelin A; D044023:Receptor, Endothelin B; D000071559:beta-Arrestin 1; D000071557:beta-Arrestins
keywords: Endothelin-1; NF-κB; Ovarian cancer; β-Arrestin-1