title: Altered protease-activated receptor-1 expression and signaling in a malignant pleural mesothelioma cell line, NCI-H28, with homozygous deletion of the β-catenin gene.
abstract: Protease activated receptors (PARs) are G-protein coupled receptors that are activated by an unique proteolytic mechanism. These receptors play crucial roles in hemostasis and thrombosis but also in inflammation and vascular development. PARs have also been implicated in tumor progression, invasion and metastasis. In this study, we investigated expression and signaling of PAR1 in nonmalignant pleural mesothelial (Met-5A) and malignant pleural mesothelioma (NCI-H28) cells. We found that the expression level of PAR1 was markedly higher in NCI-H28 cells compared to Met-5A and human primary mesothelial cells. Other three malignant pleural mesothelioma cell lines, i.e. REN, Ist-Mes2, and Mero-14, did not show any significant PAR1 over-expression compared to Met-5A cell line. Thrombin and PAR1 activating peptides enhanced Met-5A and NCI-H28 cell proliferation but in NCI-H28 cells higher thrombin concentrations were required to obtain the same proliferation increase. Similarly, thrombin caused extracellular signal-regulated kinase 1/2 activation in both cell lines but NCI-H28 cells responded at higher agonist concentrations. We also determined that PAR1 signaling through Gq and G12/13 proteins is severely altered in NCI-H28 cells compared to Met-5A cells. On the contrary, PAR1 signaling through Gi proteins was persistently maintained in NCI-H28 cells. Furthermore, we demonstrated a reduction of cell surface PAR1 expression in NCI-H28 and malignant pleural mesothelioma REN cells. Thus, our results provide evidences for dysfunctional PAR1 signaling in NCI-H28 cells together with reduced plasma membrane localization. The role of PAR1 in mesothelioma progression is just emerging and our observations can promote further investigations focused on this G-protein coupled receptor.
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Fazzini
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Vanessa
authors.initials: V
authors.lastname: D'Antongiovanni
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Giusti
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Ylenia
authors.initials: Y
authors.lastname: Da Valle
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Ciregia
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Ilaria
authors.initials: I
authors.lastname: Piano
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Caputo
authors.affiliation: Department of Pharmacy, University of Salerno, Salerno, Italy.
authors.forename: Anna Maria
authors.initials: AM
authors.lastname: D'Ursi
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: Gargini
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Lucacchini
authors.affiliation: Department of Pharmacy, University of Pisa, Pisa, Italy.
authors.forename: Maria Rosa
authors.initials: MR
authors.lastname: Mazzoni
mesh_terms: D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects; D017353:Gene Deletion; D015870:Gene Expression; D015972:Gene Expression Regulation, Neoplastic; D006720:Homozygote; D006801:Humans; D042541:Intracellular Space / Q000378:metabolism; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism*; D008654:Mesothelioma / Q000235:genetics* / Q000378:metabolism*; D000086002:Mesothelioma, Malignant; D010997:Pleural Neoplasms / Q000235:genetics* / Q000378:metabolism*; D021381:Protein Transport; D044463:Receptor, PAR-1 / Q000819:agonists / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction; D051176:beta Catenin / Q000235:genetics*
chemical_list: D044463:Receptor, PAR-1; D051176:beta Catenin