title: RNA expression patterns in serum microvesicles from patients with glioblastoma multiforme and controls.
abstract: BACKGROUND
  RNA from exosomes and other microvesicles contain transcripts of tumour origin. In this study we sought to identify biomarkers of glioblastoma multiforme in microvesicle RNA from serum of affected patients.
  
  
  METHODS
  Microvesicle RNA from serum from patients with de-novo primary glioblastoma multiforme (N = 9) and normal controls (N = 7) were analyzed by microarray analysis. Samples were collected according to protocols approved by the Institutional Review Board. Differential expressions were validated by qRT-PCR in a separate set of samples (N = 10 in both groups).
  
  
  RESULTS
  Expression profiles of microvesicle RNA correctly separated individuals in two groups by unsupervised clustering. The most significant differences pertained to down-regulated genes (121 genes > 2-fold down) in the glioblastoma multiforme patient microvesicle RNA, validated by qRT-PCR on several genes. Overall, yields of microvesicle RNA from patients was higher than from normal controls, but the additional RNA was primarily of size < 500 nt. Gene ontology of the down-regulated genes indicated these are coding for ribosomal proteins and genes related to ribosome production.
  
  
  CONCLUSIONS
  Serum microvesicle RNA from patients with glioblastoma multiforme has significantly down-regulated levels of RNAs coding for ribosome production, compared to normal healthy controls, but a large overabundance of RNA of unknown origin with size < 500 nt.
authors.affiliation: Department of Neurology, Neurosurgery and Radiology, Massachusetts General Hospital and Program in Neuroscience, Harvard Medical School, Boston, MA 02114, USA. mikkel@exosomedx.com
authors.forename: Mikkel
authors.initials: M
authors.lastname: Noerholm
authors.forename: Leonora
authors.initials: L
authors.lastname: Balaj
authors.forename: Tobias
authors.initials: T
authors.lastname: Limperg
authors.forename: Afshin
authors.initials: A
authors.lastname: Salehi
authors.forename: Lin Dan
authors.initials: LD
authors.lastname: Zhu
authors.forename: Fred H
authors.initials: FH
authors.lastname: Hochberg
authors.forename: Xandra O
authors.initials: XO
authors.lastname: Breakefield
authors.forename: Bob S
authors.initials: BS
authors.lastname: Carter
authors.forename: Johan
authors.initials: J
authors.lastname: Skog
mesh_terms: D014408:Biomarkers, Tumor / Q000097:blood*; D001932:Brain Neoplasms / Q000097:blood / Q000235:genetics*; D020869:Gene Expression Profiling; D005909:Glioblastoma / Q000097:blood / Q000235:genetics*; D006801:Humans; D046228:Microarray Analysis; D012334:RNA, Neoplasm / Q000097:blood*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013347:Subcellular Fractions / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D012334:RNA, Neoplasm