title: Identification of differentially expressed proteins in human glioblastoma cell lines and tumors.
abstract: An in-frame deletion of 801 bp in exons 2-7 (type III mutation) of the epidermal growth factor receptor (EGFR) is detected at high incidence in primary glioblastoma tumors. A proteomic approach was used to generate differential protein expression maps of fetal human astrocytes (FHA), human glioblastoma cell lines U87MG and U87MG expressing type III EGFR deletion (U87MGdeltaEGFR) that confers high malignancy to tumor cells. Two-dimensional gel electrophoresis followed by in-gel digestion of separated spots and protein identification by LC-MS-MS and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) identified 23 proteins expressed at higher levels or exclusively in FHA and 29 proteins expressed at higher levels or exclusively in U87MG cells. Three proteins, ubiquitin, cystatin B, and tissue transglutaminase (TTG), were upregulated in U87MGdeltaEGFR relative to U87MG. Four proteins highly expressed by U87MG cells, Hsp27, major vault protein, TTG, and cystatin B, were analyzed by Western blot, ELISA, or RT-PCR in cell extracts and in tissue samples of glioblastoma multiforme (GBM; grade IV), low-grade astrocytomas (grades I and II), and nonmalignant brain lesions. All four proteins were highly expressed in GBM tissues compared to nonmalignant brain. These proteins may be used as diagnostic or functional (e.g., multiple drug resistance, invasiveness) markers for glioblastoma tumors.
authors.affiliation: Institute for Biological Sciences, National Research Council, Ottawa, Canada.
authors.forename: Rulin
authors.initials: R
authors.lastname: Zhang
authors.forename: Tammy-Lynn
authors.initials: TL
authors.lastname: Tremblay
authors.forename: Angela
authors.initials: A
authors.lastname: McDermid
authors.forename: Pierre
authors.initials: P
authors.lastname: Thibault
authors.forename: Danica
authors.initials: D
authors.lastname: Stanimirovic
mesh_terms: D001253:Astrocytes / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001932:Brain Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D055313:Cystatin B; D015891:Cystatins / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D004815:Epidermal Growth Factor / Q000235:genetics; D005333:Fetus; D015972:Gene Expression Regulation, Neoplastic / Q000502:physiology; D005909:Glioblastoma / Q000175:diagnosis / Q000235:genetics / Q000378:metabolism*; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D006801:Humans; D018832:Molecular Chaperones; D009154:Mutation / Q000235:genetics; D009363:Neoplasm Proteins / Q000378:metabolism; D010766:Phosphorylation; D011506:Proteins / Q000378:metabolism*; D040901:Proteomics; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D011503:Transglutaminases / Q000378:metabolism; D014407:Tumor Cells, Cultured / Q000166:cytology / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology*; D020394:Vault Ribonucleoprotein Particles / Q000378:metabolism; D000099187:Major Vault Protein
chemical_list: D014408:Biomarkers, Tumor; D055313:Cystatin B; D015891:Cystatins; D004815:Epidermal Growth Factor; D055551:HSP27 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; D009363:Neoplasm Proteins; D011506:Proteins; D011503:Transglutaminases; D025801:Ubiquitin; D020394:Vault Ribonucleoprotein Particles; D000099187:Major Vault Protein; C524994:CSTB protein, human; C057725:HSPB1 protein, human