title: A novel splice variant of the protein tyrosine phosphatase PTPRJ that encodes for a soluble protein involved in angiogenesis.
abstract: PTPRJ is a receptor protein tyrosine phosphatase with tumor suppressor activity. Very little is known about the role of PTPRJ ectodomain, although recently both physiological and synthetic PTPRJ ligands have been identified. A putative shorter spliced variant, coding for a 539 aa protein corresponding to the extracellular N-terminus of PTPRJ, is reported in several databases but, currently, no further information is available.Here, we confirmed that the PTPRJ short isoform (named sPTPRJ) is a soluble protein secreted into the supernatant of both endothelial and tumor cells. Like PTPRJ, also sPTPRJ undergoes post-translational modifications such as glycosylation, as assessed by sPTPRJ immunoprecipitation. To characterize its functional activity, we performed an endothelial cell tube formation assay and a wound healing assay on HUVEC cells overexpressing sPTPRJ and we found that sPTPRJ has a proangiogenic activity. We also showed that sPTPRJ expression down-regulates endothelial adhesion molecules, that is a hallmark of proangiogenic activity. Moreover, sPTPRJ mRNA levels in human high-grade glioma, one of the most angiogenic tumors, are higher in tumor samples compared to controls. Further studies will be helpful not only to clarify the way sPTPRJ works but also to supply clues to circumvent its activity in cancer therapy.
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Anna
authors.initials: A
authors.lastname: Bilotta
authors.affiliation: Department of Scienze della Salute, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Dattilo
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Sabrina
authors.initials: S
authors.lastname: D'Agostino
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Belviso
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Scalise
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Mariaconcetta
authors.initials: M
authors.lastname: Bilotta
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.|Lymphoma and Genomics Research Program, Institute of Oncology Research (IOR), Bellinzona, Switzerland.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Gaudio
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.|Tecnologica Research Institute, Biomedical Section, Crotone, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Paduano
authors.affiliation: Department of Scienze della Salute, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Perrotti
authors.affiliation: Laboratory of Pharmacology, Dept. of Internal Medicine, and Center of Excellence for Biomedical Research (CEBR), University of Genova, Genova, Italy.
authors.forename: Tullio
authors.initials: T
authors.lastname: Florio
authors.affiliation: Istituto di Endocrinologia e Oncologia Sperimentale - CNR c/o Dipartimento di Medicina Molecolare e Biotecnologie Mediche, University Federico II of Napoli, Napoli, Italy.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Fusco
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Iuliano
authors.affiliation: Department of Medicina Sperimentale e Clinica, University Magna Graecia of Catanzaro, Catanzaro, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Trapasso
mesh_terms: D000072283:A549 Cells; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D002465:Cell Movement; D049109:Cell Proliferation; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006031:Glycosylation; D057809:HEK293 Cells; D006367:HeLa Cells; D061307:Human Umbilical Vein Endothelial Cells / Q000201:enzymology*; D006801:Humans; D061986:MCF-7 Cells; D060787:Neoplasm Grading; D009369:Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D009389:Neovascularization, Pathologic; D018919:Neovascularization, Physiologic; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D054631:Receptor-Like Protein Tyrosine Phosphatases, Class 3 / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D012995:Solubility; D013997:Time Factors
chemical_list: D015815:Cell Adhesion Molecules; D020033:Protein Isoforms; D012333:RNA, Messenger; C486288:PTPRJ protein, human; D054631:Receptor-Like Protein Tyrosine Phosphatases, Class 3
keywords: angiogenesis; angiogenic factor; glioblastoma; protein tyrosine phosphatase; soluble isoform