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Olig2 expression, GFAP, p53 and 1p loss analysis contribute to glioma subclassification
Author(s) -
Mokhtari K.,
Paris S.,
AguirreCruz L.,
Privat N.,
Crinière E.,
Marie Y.,
Hauw J.J.,
Kujas M.,
Rowitch D.,
HoangXuan K.,
Delattre J.Y.,
Sanson M.
Publication year - 2005
Publication title -
neuropathology and applied neurobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.538
H-Index - 95
eISSN - 1365-2990
pISSN - 0305-1846
DOI - 10.1111/j.1365-2990.2004.00612.x
Subject(s) - olig2 , oligodendroglial tumor , immunohistochemistry , glioma , pathology , astrocytoma , biology , oligodendroglioma , cancer research , medicine , oligodendrocyte , central nervous system , myelin , neuroscience
The expression of Olig2, a basic helix–loop–helix (bHLH) transcription factor involved in oligodendroglial specification, was investigated by immunohistochemistry in a series of 146 tumours and control samples. Olig2 expression was restricted to glial tumours and nontumoral oligodendrocytes. It was higher in oligodendrogliomas as compared to astrocytomas and oligoastrocytomas, and in grade III as compared to grade II tumours. Olig 2 was absent or weakly expressed in glioblastoma (GBM), whereas strong expression was found in the oligodendroglial foci of GBM with oligodendroglial component (GBMO). Double labelling was performed on a subset of the most typical tumours, according to the WHO classification. It showed a mutual exclusion, at cell level, of Olig2 and GFAP expression. In pure oligodendrogliomas, tumour cells were Olig2+/GFAP–. In contrast, two main tumour populations, Olig2+/GFAP– and Olig2–/GFAP+, were found in both oligoastrocytomas and astrocytomas. Based on these data from selected samples, two separate entities can be established, corresponding to ‘pure oligodendrogliomas’ and ‘astrocytomas and oligoastrocytomas’. The relevance of this subdivision is further supported by the association with 1p loss and a trend to better survival for pure oligodendrogliomas and with p53 expression and a trend to shorter survival for astrocytomas and oligoastrocytomas. Combined testing of Olig2, 1p status, GFAP and p53 expression may therefore be helpful in refining current classification and providing more homogeneous sets of gliomas for clinical studies.