title: Changes of AXIN-1 and beta-catenin in neuroepithelial brain tumors.
abstract: In the present study changes of components of Wnt signaling pathway--axin (AXIN1) and beta-catenin (CTNNB1) in a sample of 72 neuroepithelial brain tumors were investigated. AXIN-1 gene was tested by PCR/loss of heterozygosity (LOH). Immunostaining and image analysis revealed the quantity and localization of relevant proteins. Polymorphic marker for AXIN-1, showed LOH in 11.1% of tumors. LOH was distributed to 6.3% of glioblastomas, one was found in neuroepithelial dysembrioplastic tumor and one in medulloblastoma. Down regulation of axin expression and up regulation of beta-catenin were detected in the analyzed tumors. Axin was observed in the cytoplasm in 68.8% of samples, in 28.1% in both the cytoplasm and nucleus and 3.1% had no expression. Beta-catenin was observed mainly in the nucleus and cytoplasm (59.4%). Expression in 34.4% of samples was in the cytoplasm and 6.3% showed no expression. Comparison of mean values of relative increase of axin and beta-catenin showed that they are significantly reversely proportional (P = 0.014). Relative quantity of beta-catenin in patients with gross deletion of AXIN1 was significantly higher in comparison to patients without LOH (P = 0.040). Our results demonstrate that changes of key components of the Wnt signaling play a role in neuroepithelial brain tumors.
authors.affiliation: Laboratory of Neurooncology, Croatian Institute for Brain Research, School of Medicine University of Zagreb, Salata 12, 10000, Zagreb, Croatia.
authors.forename: Tamara
authors.initials: T
authors.lastname: Nikuseva Martić
authors.forename: Nives
authors.initials: N
authors.lastname: Pećina-Slaus
authors.forename: Vesna
authors.initials: V
authors.lastname: Kusec
authors.forename: Tomislav
authors.initials: T
authors.lastname: Kokotović
authors.forename: Hana
authors.initials: H
authors.lastname: Musinović
authors.forename: Davor
authors.initials: D
authors.lastname: Tomas
authors.forename: Martina
authors.initials: M
authors.lastname: Zeljko
mesh_terms: D060466:Axin Protein; D001932:Brain Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D007150:Immunohistochemistry; D019656:Loss of Heterozygosity; D018302:Neoplasms, Neuroepithelial / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016133:Polymerase Chain Reaction; D012097:Repressor Proteins / Q000096:biosynthesis* / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000096:biosynthesis* / Q000235:genetics
chemical_list: C555451:AXIN1 protein, human; D060466:Axin Protein; D012097:Repressor Proteins; D051153:Wnt Proteins; D051176:beta Catenin