title: EGFRvIII promotes glioma angiogenesis and growth through the NF-κB, interleukin-8 pathway.
abstract: Sustaining a high growth rate requires tumors to exploit resources in their microenvironment. One example of this is the extensive angiogenesis that is a typical feature of high-grade gliomas. Here, we show that expression of the constitutively active mutant epidermal growth factor receptor, ΔEGFR (EGFRvIII, EGFR*, de2-7EGFR) is associated with significantly higher expression levels of the pro-angiogenic factor interleukin (IL)-8 in human glioma specimens and glioma stem cells. Furthermore, the ectopic expression of ΔEGFR in different glioma cell lines caused up to 60-fold increases in the secretion of IL-8. Xenografts of these cells exhibit increased neovascularization, which is not elicited by cells overexpressing wild-type (wt)EGFR or ΔEGFR with an additional kinase domain mutation. Analysis of the regulation of IL-8 by site-directed mutagenesis of its promoter showed that ΔEGFR regulates its expression through the transcription factors nuclear factor (NF)-κB, activator protein 1 (AP-1) and CCAAT/enhancer binding protein (C/EBP). Glioma cells overexpressing ΔEGFR showed constitutive activation and DNA binding of NF-κB, overexpression of c-Jun and activation of its upstream kinase c-Jun N-terminal kinase (JNK) and overexpression of C/EBPβ. Selective pharmacological or genetic targeting of the NF-κB or AP-1 pathways efficiently blocked promoter activity and secretion of IL-8. Moreover, RNA interference-mediated knock-down of either IL-8 or the NF-κB subunit p65, in ΔEGFR-expressing cells attenuated their ability to form tumors and to induce angiogenesis when injected subcutaneously into nude mice. On the contrary, the overexpression of IL-8 in glioma cells lacking ΔEGFR potently enhanced their tumorigenicity and produced highly vascularized tumors, suggesting the importance of this cytokine and its transcription regulators in promoting glioma angiogenesis and tumor growth.
authors.affiliation: Ludwig Institute for Cancer Research, University of California, La Jolla, CA, USA.
authors.forename: R
authors.initials: R
authors.lastname: Bonavia
authors.forename: M M
authors.initials: MM
authors.lastname: Inda
authors.forename: S
authors.initials: S
authors.lastname: Vandenberg
authors.forename: S-Y
authors.initials: SY
authors.lastname: Cheng
authors.forename: M
authors.initials: M
authors.lastname: Nagane
authors.forename: P
authors.initials: P
authors.lastname: Hadwiger
authors.forename: P
authors.initials: P
authors.lastname: Tan
authors.forename: D W Y
authors.initials: DW
authors.lastname: Sah
authors.forename: W K
authors.initials: WK
authors.lastname: Cavenee
authors.forename: F B
authors.initials: FB
authors.lastname: Furnari
mesh_terms: D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D066246:ErbB Receptors; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000098:blood supply* / Q000473:pathology; D061307:Human Umbilical Vein Endothelial Cells / Q000502:physiology; D006801:Humans; D016209:Interleukin-8 / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020935:MAP Kinase Signaling System; D051379:Mice; D008819:Mice, Nude; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009368:Neoplasm Transplantation; D014411:Neoplastic Stem Cells / Q000378:metabolism; D009389:Neovascularization, Pathologic / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011499:Protein Processing, Post-Translational; D020218:Response Elements; D013450:Sulfones / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000378:metabolism; D015533:Transcriptional Activation; D047368:Tumor Burden; D018631:ras Proteins / Q000378:metabolism
chemical_list: C434003:3-(4-methylphenylsulfonyl)-2-propenenitrile; D022762:CCAAT-Enhancer-Binding Proteins; D016209:Interleukin-8; D016328:NF-kappa B; D009570:Nitriles; D047428:Protein Kinase Inhibitors; D013450:Sulfones; D018808:Transcription Factor AP-1; C410723:epidermal growth factor receptor VIII; D019869:Phosphatidylinositol 3-Kinases; D066246:ErbB Receptors; D048031:JNK Mitogen-Activated Protein Kinases; D018631:ras Proteins