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Analysis of the bHLH Transcription
Factors Olig1 and Olig2 in Brain Tumors
Lucinda Aguirre-Cruz, Karima Mokhtari, Khê
Hoang-Xuan, Yannick Marie, Emmanuelle Criniere, Sophie
Taillibert, Manuel Lopes, Jean-Yves Delattre, Marc Sanson
INSERM
U495, Laboratoire de Biologie des Interactions Neurones-Glie (L.A.-C., K.H.X.,
Y.M., E.C., J.-Y.D., M.S.); Instituto Nacional de Neurologia y Neurocirugia,
Mexico D.F., Mexico (L.A.-C.); Laboratoire de neuropathologie R Escourolle (Pr
Hauw) (K.M.); Fédération de Neurologie Mazarin (K.H.X., S.T., J.-Y.D.,
M.S.); Service de Neurochirurgie, Groupe hospitalier Pitié-Salpêtrière and Université
Pierre et Marie Curie, Paris, France (M.L.).
In the absence of specific markers, the histological diagnosis of
oligodendroglial tumors is based on subjective qualitative criteria and remains
controversial.
Recently, two bHLH transcription factors involved in oligodendroglial
specification, Olig1 and Olig2 have been proposed as potential markers of
oligodendrogliomas.
Expression of Olig1/2 was analyzed by in situ hybridization on
78 samples including 47 glial, 29 non-glial tumors, and two non-tumoral brain
tissues.
Both genes had a similar pattern of expression.
Olig1 and Olig2 were expressed in 26/30 (87%) and 28/30 (93%) of
oligodendroglial tumors respectively but in only 9% of glioblastomas
(1/11).
Olig genes were also expressed in the low-grade fibrillary astrocytomas (4/4)
and anaplastic astrocytomas (2/2).
No expression was found in non-glial tumors, except for one primary cerebral
lymphoma.
Double staining with PLP, NFH, GFAP showed that olig genes were expressed by
mature, non-tumoral oligodendrocytes, but not by normal astrocytes or neurones.
This study indicates that Olig1/2 expression clearly distinguishes pure
Olig-negative glioblastomas from a wide spectrum of Olig-positive tumors
including traditional oligodendrogliomas and oligoastrocytomas, glioblastomas
with an oligodendroglial component (GBMO), and WHO grade 2 and 3
astrocytomas.
Because Olig genes have a crucial role in oligodendroglial determination, our
data could be of help in defining the real spectrum of oligodendroglial tumors.
Keywords: bHLH, gliomas, Olig1, Olig2, oligodendrogliomas
Copyright
©
2004 Kluwer Academic Publishers.
All rights reserved
Source:
http://journals.kluweronline.com/article.asp?PIPS=5256316
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