title: NG2 expression in glioblastoma identifies an actively proliferating population with an aggressive molecular signature.
abstract: Glioblastoma multiforme (GBM) is the most common type of primary brain tumor and a highly malignant and heterogeneous cancer. Current conventional therapies fail to eradicate or curb GBM cell growth. Hence, exploring the cellular and molecular basis of GBM cell growth is vital to develop novel therapeutic approaches. Neuroglia (NG)-2 is a transmembrane proteoglycan expressed by NG2+ progenitors and is strongly linked to cell proliferation in the normal brain. By using NG2 as a biomarker we identify a GBM cell population (GBM NG2+ cells) with robust proliferative, clonogenic, and tumorigenic capacity. We show that a significant proportion (mean 83%) of cells proliferating in the tumor mass express NG2 and that over 50% of GBM NG2+ cells are proliferating. Compared with the GBM NG2- cells from the same tumor, the GBM of NG2+ cells overexpress genes associated with aggressive tumorigenicity, including overexpression of Mitosis and Cell Cycling Module genes (e.g., MELK, CDC, MCM, E2F), which have been previously shown to correlate with poor survival in GBM. We also show that the coexpression pattern of NG2 with other glial progenitor markers in GBM does not recapitulate that described in the normal brain. The expression of NG2 by such an aggressive and actively cycling GBM population combined with its location on the cell surface identifies this cell population as a potential therapeutic target in a subset of patients with GBM.
authors.affiliation: Cambridge Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge CB2 0PY, UK.
authors.forename: M Talal F
authors.initials: MT
authors.lastname: Al-Mayhani
authors.forename: Richard
authors.initials: R
authors.lastname: Grenfell
authors.forename: Masashi
authors.initials: M
authors.lastname: Narita
authors.forename: Sara
authors.initials: S
authors.lastname: Piccirillo
authors.forename: Emma
authors.initials: E
authors.lastname: Kenney-Herbert
authors.forename: James W
authors.initials: JW
authors.lastname: Fawcett
authors.forename: V Peter
authors.initials: VP
authors.lastname: Collins
authors.forename: Koichi
authors.initials: K
authors.lastname: Ichimura
authors.forename: Colin
authors.initials: C
authors.lastname: Watts
mesh_terms: D000818:Animals; D000941:Antigens / Q000378:metabolism*; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D045744:Cell Line, Tumor / Q000637:transplantation; D049109:Cell Proliferation; D055028:Comparative Genomic Hybridization; D005260:Female; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D051379:Mice; D008813:Mice, Inbred ICR; D016513:Mice, SCID; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D011509:Proteoglycans / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D000941:Antigens; D014408:Biomarkers, Tumor; D011509:Proteoglycans; D012333:RNA, Messenger; D000099216:Chondroitin Sulfate Proteoglycan 4