Authors: Rolf Buslei Michael Nolde Bernd Hofmann Stephan Meissner Ilker Y Eyupoglu Florian Siebzehnrübl Eric Hahnen Jürgen Kreutzer Rudolf Fahlbusch
Publish Date: 2005/05/13
Volume: 109, Issue: 6, Pages: 589-597
Abstract
Dysregulation of the Wnt signalling pathway contributes to developmental abnormalities and carcinogenesis of solid tumours Here we examined βcatenin and adenomatous polyposis coli APC by mutational analysis in pituitary adenomas n=60 and a large series of craniopharyngiomas n=41 Furthermore the expression pattern of βcatenin was immunohistochemically analysed in a cohort of tumours and cysts of the sellar region including pituitary adenomas n=58 craniopharyngiomas n=57 arachnoidal cysts n=8 Rathke’s cleft cysts n=10 and xanthogranulomas n=6 Whereas APC mutations were not detectable in any tumour entity βcatenin mutations were present in 77 of craniopharyngiomas exclusively of the adamantinomatous subtype All mutations affected exon 3 which encodes the degradation targeting box of βcatenin compatible with an accumulation of nuclear βcatenin protein In addition a novel 81bp deletion of this exonic region was detected in one case Immunohistochemical analysis confirmed a shift from membranebound to nuclear accumulation of βcatenin in 94 of the adamantinomatous tumours Aberrant distribution patterns of βcatenin were never observed in the other tumour entities under study We conclude that βcatenin mutations and/or nuclear accumulation serve as diagnostic hallmarks of the adamantinomatous variant setting it apart from the papillary variant of craniopharyngiomaWe thank Dr I Blümcke University of Erlangen Germany and Dr A Koch University of Bonn Germany for helpful discussions We thank V Schmidt S Gutmann and B Rings for expert technical assistance The work is supported by ELAN and Marohn funds from the University of Erlangen Medical Faculty
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