Underediting of glutamate receptor GluR-B mRNA in malignant gliomas

Proc Natl Acad Sci U S A. 2001 Dec 4;98(25):14687-92. doi: 10.1073/pnas.251531398. Epub 2001 Nov 20.


In mammals, RNA editing by site-selective adenosine deamination regulates key functional properties of neurotransmitter receptors in the central nervous system. Glutamate receptor subunit B is nearly 100% edited at one position (the Q/R-site), which is essential for normal receptor function. Its significance is apparent from mouse models in which a slightly reduced rate of Q/R-site editing is associated with early onset epilepsy and premature death. Here we report that in tissues from malignant human brain tumors, this editing position of glutamate receptor subunit B is substantially underedited compared with control tissues. We also observe alterations in editing and alternative splicing of serotonin receptor 5-HT(2C) transcripts. These changes correlate with a decrease in enzymatic activity of the editing enzyme adenosine deaminase acting on RNA (ADAR) 2, as deduced from analysis of ADAR2 self-editing. Our results suggest a role for RNA editing in tumor progression and may provide a molecular model explaining the occurrence of epileptic seizures in association with malignant gliomas.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Deaminase / metabolism
  • Alternative Splicing
  • Astrocytoma / genetics
  • Astrocytoma / metabolism
  • Brain Neoplasms / genetics*
  • Brain Neoplasms / metabolism*
  • Glioblastoma / genetics*
  • Glioblastoma / metabolism*
  • Humans
  • RNA Editing*
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins
  • Receptors, AMPA / genetics*
  • Receptors, Serotonin / genetics
  • Receptors, Serotonin / metabolism
  • Tumor Cells, Cultured


  • RNA, Messenger
  • RNA-Binding Proteins
  • Receptors, AMPA
  • Receptors, Serotonin
  • glutamate receptor type B
  • ADARB1 protein, human
  • Adenosine Deaminase