title: Construction of a ganciclovir-sensitive lentiviral vector to assess the influence of angiopoietin-3 and soluble Tie2 on glioma growth.
abstract: Malignant brain tumors grow by coopting the existing vasculature, a process involving the release of angiopoietin-2 (Angpt2) from endothelial cells and its binding to the Tie2 receptor. The first goal of this study was to examine the therapeutic potential of two proteins that could interfere with Angpt2, namely Angpt3 and the soluble extracellular domain of Tie2 (sTie2). The second goal was to develop a lentiviral vector capable of delivering such proteins while offering the possibility to identify and destroy the genetically modified cells. To this end, we designed a bicistronic construct expressing the marker enhanced green fluorescent protein fused to the suicide gene herpes simplex virus 1 thymidine kinase. GL261 glioma cells transduced with this vector could be tracked and killed on command by the administration of the prodrug ganciclovir, either in vitro or after implantation into mouse brains. High levels of Angpt3 or sTie2 could be achieved with this vector; however, Angpt3 increased capillary destabilization and glioma growth, whereas sTie2 exerted no effect. Overall, this study helps to understand the importance of the Tie2 signaling pathway in glioma development and the role of Angpt3, but suggests that neither this molecule nor sTie2 are effective agents against malignant gliomas. This study also provides a lentiviral vector design for safer gene therapy.
authors.affiliation: Department of Endocrinology and Genomics, Laval University Hospital Research Center, 2705 Laurier Boulevard, Quebec City, QC G1V 4G2, Canada.
authors.forename: Marie-Josée
authors.initials: MJ
authors.lastname: Beaudet
authors.forename: Naika
authors.initials: N
authors.lastname: Rueda
authors.forename: Gary P
authors.initials: GP
authors.lastname: Kobinger
authors.forename: Jérôme
authors.initials: J
authors.lastname: Villeneuve
authors.forename: Luc
authors.initials: L
authors.lastname: Vallières
mesh_terms: D000704:Analysis of Variance; D000091304:Angiopoietin-Like Protein 1; D000075802:Angiopoietin-like Proteins; D042682:Angiopoietins / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001973:Bromodeoxyuridine / Q000378:metabolism; D048708:Cell Growth Processes / Q000187:drug effects; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D015774:Ganciclovir / Q000494:pharmacology / Q000627:therapeutic use*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects* / Q000235:genetics; D005822:Genetic Vectors / Q000627:therapeutic use; D005910:Glioma / Q000175:diagnosis / Q000188:drug therapy* / Q000235:genetics / Q000401:mortality; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D042787:Receptor, TIE-2 / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic / Q000379:methods; D014162:Transfection / Q000379:methods
chemical_list: C117578:ANGPTL1 protein, human; D000091304:Angiopoietin-Like Protein 1; D000075802:Angiopoietin-like Proteins; D042682:Angiopoietins; D000998:Antiviral Agents; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D042787:Receptor, TIE-2; D001973:Bromodeoxyuridine; D015774:Ganciclovir