OLIG-1 and 2 gene expression and oligodendroglial tumours.
OLIG 1/2 genes encode basic helix-loop-helix transcription factors that play a critical role in motor neurone and oligodendrocyte fate specification during development. Two recent studies in which OLIG transcripts were detected by in situ hybridization have reported a high expression of the OLIG genes in oligodendrogliomas. This suggests that the detection of these lineage markers could become an adjunct to the classic morphological diagnosis of these tumours. There are problems in the diagnosis of oligodendroglioma. To date, all other known oligodendrocyte lineage markers have failed to label specifically neoplastic oligodendrocytes. Deletions on chromosome 1p and 19q are much more frequent in oligodendrogliomas than in astrocytomas but these molecular alterations are not constant. For the future, when routinely available, immunohistochemical techniques using anti-OLIG antibodies on paraffin embedded tissues will allow a systematic study of a large series of tumours so that we will know the specificity and sensitivity of this investigation in diagnosis. At another level, it is possible that expression of OLIG in neoplastic oligodendrocyte might participate in the oncogenesis of oligodendrogliomas. Initial work suggests that this is probably not the case. However further in vitro and in vivo studies analysing the functional consequence of OLIG overexpression in terms of proliferation and tumour progression are needed.
Hoang-Xuan
Khe
K
Laboratoire de Biologie des Interactions Neurone-Glie, INSERM U495, Groupe Hospitalier Pitié-Salpêtrière, 47 boulevard de l'Hôpital, 75651 Paris Cedex 13, France. khe.hoang-xuan@psl.ap-hop-paris.fr
Aguirre-Cruz
L
L
Mokhtari
K
K
Marie
Y
Y
Sanson
M
M
D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins; D001932:Brain Neoplasms / Q000235:genetics*; D004268:DNA-Binding Proteins; D015870:Gene Expression; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics*; D000076104:Oligodendrocyte Transcription Factor 2; D009837:Oligodendroglioma / Q000235:genetics*
D051792:Basic Helix-Loop-Helix Proteins; D004268:DNA-Binding Proteins; D009419:Nerve Tissue Proteins; D000076104:Oligodendrocyte Transcription Factor 2; C405707:OLIG1 protein, human; C405708:OLIG2 protein, human