Changes of AXIN-1 and beta-catenin in neuroepithelial brain tumors

Pathol Oncol Res. 2010 Mar;16(1):75-9. doi: 10.1007/s12253-009-9190-9. Epub 2009 Jul 25.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Axin Protein
  • Brain Neoplasms / genetics
  • Brain Neoplasms / metabolism*
  • Brain Neoplasms / pathology
  • Gene Expression
  • Gene Expression Profiling
  • Humans
  • Image Interpretation, Computer-Assisted
  • Immunohistochemistry
  • Loss of Heterozygosity
  • Neoplasms, Neuroepithelial / genetics
  • Neoplasms, Neuroepithelial / metabolism*
  • Neoplasms, Neuroepithelial / pathology
  • Polymerase Chain Reaction
  • Repressor Proteins / biosynthesis*
  • Repressor Proteins / genetics
  • Signal Transduction / genetics
  • Wnt Proteins / genetics
  • Wnt Proteins / metabolism
  • beta Catenin / biosynthesis*
  • beta Catenin / genetics

Substances

  • AXIN1 protein, human
  • Axin Protein
  • Repressor Proteins
  • Wnt Proteins
  • beta Catenin