title: ERG is a novel and reliable marker for endothelial cells in central nervous system tumors.
abstract: ETS-related gene (ERG) is a transcription factor that has been linked to angiogenesis. Very little research has been done to assess ERG expression in central nervous system (CNS) tumors. We evaluated 57 CNS tumors, including glioblastomas (GBMs) and hemangioblastomas (HBs), as well as two arteriovenous malformations and four samples of normal brain tissue with immunohistochemistry using a specific ERG rabbit monoclonal antibody. In addition, immunostains for CD31, CD34, and α-smooth muscle actin (α-SMA) were performed on all samples. CD31 demonstrated variable and sometimes weak immunoreactivity for endothelial cells. Furthermore, in 1 case of a GBM, CD34 stained not only endothelial cells, but also tumor cells. In contrast, we observed that ERG was only expressed in the nuclei of endothelial cells, for example, in the hyperplastic vascular complexes that comprise the glomeruloid microvascular proliferation seen in GBMs. Conversely, α-SMA immunoreactivity was identified in the abluminal cells of these hyperplastic vessels. Quantitative evaluation with automated methodology and custom Matlab 2008b software was used to calculate percent staining of ERG in each case. We observed significantly higher quantitative expression of ERG in HBs than in other CNS tumors. Our results show that ERG is a novel, reliable, and specific marker for endothelial cells within CNS tumors that can be used to better study the process of neovascularization.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Haber
authors.forename: Amir
authors.initials: A
authors.lastname: Iranmahboob
authors.forename: Cheddhi
authors.initials: C
authors.lastname: Thomas
authors.forename: Mengling
authors.initials: M
authors.lastname: Liu
authors.forename: Amanda
authors.initials: A
authors.lastname: Najjar
authors.forename: David
authors.initials: D
authors.lastname: Zagzag
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D001932:Brain Neoplasms / Q000473:pathology*; D042783:Endothelial Cells / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology*; D015534:Trans-Activators / Q000032:analysis / Q000096:biosynthesis*; D000071230:Transcriptional Regulator ERG; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; C072312:ERG protein, human; D015534:Trans-Activators; D000071230:Transcriptional Regulator ERG