title: HSV-1 Cgal+ infection promotes quaking RNA binding protein production and induces nuclear-cytoplasmic shuttling of quaking I-5 isoform in human hepatoma cells.
abstract: Herpesvirus type 1 (HSV-1) based oncolytic vectors arise as a promising therapeutic alternative for neoplastic diseases including hepatocellular carcinoma. However, the mechanisms mediating the host cell response to such treatments are not completely known. It is well established that HSV-1 infection induces functional and structural alterations in the nucleus of the host cell. In the present work, we have used gel-based and shotgun proteomic strategies to elucidate the signaling pathways impaired in the nucleus of human hepatoma cells (Huh7) upon HSV-1 Cgal(+) infection. Both approaches allowed the identification of differential proteins suggesting impairment of cell functions involved in many aspects of host-virus interaction such as transcription regulation, mRNA processing, and mRNA splicing. Based on our proteomic data and additional functional studies, cellular protein quaking content (QKI) increases 4 hours postinfection (hpi), when viral immediate-early genes such as ICP4 and ICP27 could be also detected. Depletion of QKI expression by small interfering RNA results in reduction of viral immediate-early protein levels, subsequent decrease in early and late viral protein content, and a reduction in the viral yield indicating that QKI directly interferes with viral replication. In particular, HSV-1 Cgal(+) induces a transient increase in quaking I-5 isoform (QKI-5) levels, in parallel with an enhancement of p27(Kip1) protein content. Moreover, immunofluorescence microscopy showed an early nuclear redistribution of QKI-5, shuttling from the nucleus to the cytosol and colocalizing with nectin-1 in cell to cell contact regions at 16-24 hpi. This evidence sheds new light on mechanisms mediating hepatoma cell response to HSV-1 vectors highlighting QKI as a central molecular mediator.
authors.affiliation: Division of Hepatology and Gene Therapy, Centre for Applied Medical Research (CIMA), University of Navarra, Pamplona, Spain.
authors.forename: Virginia
authors.initials: V
authors.lastname: Sánchez-Quiles
authors.forename: María I
authors.initials: MI
authors.lastname: Mora
authors.forename: Victor
authors.initials: V
authors.lastname: Segura
authors.forename: Anna
authors.initials: A
authors.lastname: Greco
authors.forename: Alberto L
authors.initials: AL
authors.lastname: Epstein
authors.forename: Maria Giovanna
authors.initials: MG
authors.lastname: Foschini
authors.forename: Loïc
authors.initials: L
authors.lastname: Dayon
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Sanchez
authors.forename: Jesús
authors.initials: J
authors.lastname: Prieto
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Corrales
authors.forename: Enrique
authors.initials: E
authors.lastname: Santamaría
mesh_terms: D000465:Algorithms; D015815:Cell Adhesion Molecules / Q000378:metabolism; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism* / Q000821:virology; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000378:metabolism; D050761:Cyclin-Dependent Kinase Inhibitor p57 / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism*; D006561:Herpes Simplex / Q000378:metabolism* / Q000821:virology; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D006801:Humans; D000075983:Nectins; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D034622:RNA Interference; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018709:Statistics, Nonparametric; D053719:Tandem Mass Spectrometry; D057825:Two-Dimensional Difference Gel Electrophoresis; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000378:metabolism
chemical_list: C493964:CDKN1C protein, human; D015815:Cell Adhesion Molecules; D050761:Cyclin-Dependent Kinase Inhibitor p57; C000619010:NECTIN1 protein, human; D000075983:Nectins; D020033:Protein Isoforms; C490832:QKI protein, human; D016601:RNA-Binding Proteins; D014764:Viral Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27