title: Herpes simplex virus 1 amplicon vector-mediated siRNA targeting epidermal growth factor receptor inhibits growth of human glioma cells in vivo.
abstract: In primary glioblastomas and other tumor types, the epidermal growth factor receptor (EGFR) is frequently observed with alterations, such as amplification, structural rearrangements, or overexpression of the gene, suggesting an important role in glial tumorigenesis and progression. In this study, we investigated whether posttranscriptional gene silencing by vector-mediated RNAi to inhibit EGFR expression can reduce the growth of cultured human gli36 glioma cells. To "knock down" EGFR expression, we have created HSV-1-based amplicons that contain the RNA polymerase III-dependent H1 promoter to express double-stranded hairpin RNA directed against EGFR at two different locations (pHSVsiEGFR I and pHSVsiEGFR II). We demonstrate that both pHSVsiEGFR I and pHSVsiEGFR II mediated knock-down of transiently transfected full-length EGFR or endogenous EGFR in a dose-dependent manner. The knock-down of EGFR resulted in the growth inhibition of human glioblastoma (gli36-luc) cells both in culture and in athymic mice in vivo. Cell cycle analysis and annexin V staining revealed that siRNA-mediated suppression of EGFR induced apoptosis. Overall HSV-1 amplicons can mediate efficient and specific posttranscriptional gene silencing.
authors.affiliation: Institute of Virology, University of Zurich, Winterthurerstrasse 266a, CH-8057 Zurich, Switzerland.
authors.forename: Okay
authors.initials: O
authors.lastname: Saydam
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Glauser
authors.forename: Irma
authors.initials: I
authors.lastname: Heid
authors.forename: Gulen
authors.initials: G
authors.lastname: Turkeri
authors.forename: Monika
authors.initials: M
authors.lastname: Hilbe
authors.forename: Andreas H
authors.initials: AH
authors.lastname: Jacobs
authors.forename: Mathias
authors.initials: M
authors.lastname: Ackermann
authors.forename: Cornel
authors.initials: C
authors.lastname: Fraefel
mesh_terms: D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D018014:Gene Transfer Techniques; D018773:Genes, erbB-1; D015316:Genetic Therapy; D005822:Genetic Vectors; D005909:Glioblastoma / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D018259:Herpesvirus 1, Human / Q000235:genetics*; D006801:Humans; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000627:therapeutic use*; D014407:Tumor Cells, Cultured
chemical_list: D034741:RNA, Small Interfering; D066246:ErbB Receptors