title: CTNNB1 (beta-catenin) mutation is rare in brain tumours but involved as a sporadic event in a brain metastasis.
abstract: BACKGROUND
  The Wnt signaling pathway has been implicated in colon and other cancers. Nevertheless, few or no mutations of CTNNB1 (beta-catenin) have so far been described in brain cancer. We therefore examined the prevalence of constitutive activation of the Wnt signaling pathway in brain cancer specimens as well as cancer cell lines.
  
  
  METHODS
  We used polymerase chain reaction PCR and direct sequencing methods to investigate whether mutations in the CTNNB1 phosphorylation sites S33, S37, S41 and T45 were present in 68 brain tumours, including meningioma, astrocytoma, pituitary adenoma, neuroblastoma, metastasis to the brain, and cell lines.
  
  
  RESULTS
  CTNNB1 gene mutations were not found in either the original brain tumour specimens or the cell lines. However, a missense mutation of CTNNB1 was identified at residue 33, TCT (Ser) --> TGT (Cys) in a patient with lung metastasis to brain. In addition, in vitro functional assay showed that the S33C mutant of beta-catenin did affect transcriptional activity in a TCF-4-luciferase reporter construct.
  
  
  CONCLUSIONS
  These results indicate that the mutation of exon 3 of the CTNNB1 gene in brain tumours may be a rare event and yet may be required for a small subset of human metastatic brain tumours.
authors: Department of Medical Technology, Fooyin University, Kaohsiung, Taiwan, People's Republic of China.
authors: Chu-I
authors: CI
authors: Lee
authors: Meng-Yu
authors: MY
authors: Hsu
authors: Chia-Hua
authors: CH
authors: Chou
authors: Chihuei
authors: C
authors: Wang
authors: Yu-Shung
authors: YS
authors: Lo
authors: Joon-Khim
authors: JK
authors: Loh
authors: Shen-Long
authors: SL
authors: Howng
authors: Yi-Ren
authors: YR
authors: Hong
mesh_terms: D014408:Biomarkers, Tumor / Q000235:genetics; D001932:Brain Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000556:secondary; D002277:Carcinoma / Q000556:secondary; D020134:Catalytic Domain / Q000235:genetics; D045744:Cell Line, Tumor; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D005787:Gene Frequency; D005819:Genetic Markers; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005820:Genetic Testing; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology; D009154:Mutation / Q000235:genetics*; D009362:Neoplasm Metastasis / Q000235:genetics* / Q000503:physiopathology; D010766:Phosphorylation; D015398:Signal Transduction / Q000235:genetics; D015533:Transcriptional Activation / Q000235:genetics; D051153:Wnt Proteins / Q000235:genetics; D051176:beta Catenin / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; D005819:Genetic Markers; D051153:Wnt Proteins; D051176:beta Catenin