title: Gene silencing for epidermal growth factor receptor variant III induces cell-specific cytotoxicity.
abstract: Epidermal growth factor receptor variant III (EGFRvIII) is a constitutively active mutant form of EGFR that is expressed in 40% to 50% of gliomas and several other malignancies. Here, we describe the therapeutic effects of silencing EGFRvIII on glioma cell lines in vitro and in vivo. A small interfering RNA molecule against EGFRvIII was introduced into EGFRvIII-expressing glioma cells (U87Delta) by electroporation resulting in complete inhibition of expression of EGFRvIII as early as 48 h post-treatment. During EGFRvIII silencing, a decrease in the proliferation and invasiveness of U87Delta cells was accompanied by an increase in apoptosis (P < 0.05). Notably, EGFRvIII silencing inhibited the signal transduction machinery downstream of EGFRvIII as evidenced by decreases in the activated levels of Ras and extracellular signal-regulated kinase. A lentivirus capable of expressing anti-EGFRvIII short hairpin RNA was also able to achieve progressive silencing of EGFRvIII in U87Delta cells in addition to inhibiting cell proliferation, invasiveness, and colony formation in a significant manner (P < 0.05). Silencing EGFRvIII in U87Delta cultures with this virus reduced the expression of factors involved in epithelial-mesenchymal transition including N-cadherin, beta-catenin, Snail, Slug, and paxillin but not E-cadherin. The anti-EGFRvIII lentivirus also affected the cell cycle progression of U87Delta cells with a decrease in G(1) and increase in S and G(2) fractions. In an in vivo model, tumor growth was completely inhibited in severe combined immunodeficient mice (n = 10) injected s.c. with U87Delta cells treated with the anti-EGFRvIII lentivirus (P = 0.005). We conclude that gene specific silencing of EGFRvIII is a promising strategy for treating cancers that contain this mutated receptor.
authors.affiliation: Department of Medicine, The University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, KS 66160, USA.
authors.forename: Farnaz
authors.initials: F
authors.lastname: Yamoutpour
authors.forename: Vidya
authors.initials: V
authors.lastname: Bodempudi
authors.forename: Shay E
authors.initials: SE
authors.lastname: Park
authors.forename: Weihong
authors.initials: W
authors.lastname: Pan
authors.forename: Mary Jean
authors.initials: MJ
authors.lastname: Mauzy
authors.forename: Robert A
authors.initials: RA
authors.lastname: Kratzke
authors.forename: Arkadiusz
authors.initials: A
authors.lastname: Dudek
authors.forename: David A
authors.initials: DA
authors.lastname: Potter
authors.forename: Richard A
authors.initials: RA
authors.lastname: Woo
authors.forename: Donald M
authors.initials: DM
authors.lastname: O'Rourke
authors.forename: Donald J
authors.initials: DJ
authors.lastname: Tindall
authors.forename: Faris
authors.initials: F
authors.lastname: Farassati
mesh_terms: D000818:Animals; D017209:Apoptosis; D001483:Base Sequence; D002453:Cell Cycle; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D066246:ErbB Receptors / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D016513:Mice, SCID; D008969:Molecular Sequence Data; D009369:Neoplasms / Q000378:metabolism / Q000628:therapy*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D018631:ras Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D034741:RNA, Small Interfering; C410723:epidermal growth factor receptor VIII; D066246:ErbB Receptors; D048049:Extracellular Signal-Regulated MAP Kinases; D018631:ras Proteins