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Potential Canonical Wnt Pathway Activation in High-Grade Astrocytomas

Aberrant wnt pathway activation through cytoplasmic stabilization of β-catenin is crucial for the development of various human malignancies. In gliomagenesis, the role of canonical (i.e., β-catenin-dependent) signalling is largely unknown. Here, we studied canonical wnt pathway activation in 15 shor...

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Detalles Bibliográficos
Autores principales: Schüle, Rebecca, Dictus, Christine, Campos, Benito, Wan, Feng, Felsberg, Jörg, Ahmadi, Rezvan, Centner, Franz-Simon, Grabe, Niels, Reifenberger, Guido, Bermejo, Justo L., Unterberg, Andreas, Herold-Mende, Christel
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Scientific World Journal 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3419426/
https://www.ncbi.nlm.nih.gov/pubmed/22919349
http://dx.doi.org/10.1100/2012/697313
Descripción
Sumario:Aberrant wnt pathway activation through cytoplasmic stabilization of β-catenin is crucial for the development of various human malignancies. In gliomagenesis, the role of canonical (i.e., β-catenin-dependent) signalling is largely unknown. Here, we studied canonical wnt pathway activation in 15 short-term cultures from high-grade gliomas and potential pathomechanisms leading to cytoplasmic β-catenin accumulation. Furthermore, we assessed the prognostic relevance of β-catenin expression in a tissue microarray comprising 283 astrocytomas. Expression of β-catenin, its transcriptional cofactors TCF-1 and TCF-4 as well as GSK-3β and APC, constituents of the β-catenin degradation complex was confirmed by RT-PCR in all cultures. A cytoplasmic β-catenin pool was detectable in 13/15 cultures leading to some transcriptional activity assessed by luciferase reporter gene assay in 8/13. Unlike other malignancies, characteristic mutations of β-catenin and APC leading to cytoplasmic stabilization of β-catenin were excluded by direct sequencing or protein truncation test. In patient tissues, β-catenin expression was directly and its degradation product's (β-catenin-P654) expression was inversely correlated with WHO grade. Increased β-catenin expression and low β-catenin-P654 expression were associated with shorter survival. Altogether, we report on potential canonical wnt pathway activation in high-grade gliomas and demonstrate that β-catenin expression in astrocytomas is associated with increased malignancy and adverse outcome.