title: Complementary roles of β-catenin and glutamine synthetase immunostaining in diagnosis of chemotherapy-treated and untreated hepatoblastoma.
abstract: OBJECTIVE
  This study aimed to evaluate the expression of β-catenin and its downstream target glutamine synthetase (GS) in hepatoblastoma (HB), and to evaluate the use of these two markers for diagnosing HB.
  
  
  METHODS
  Eighteen untreated HBs and 22 HBs resected after neoadjuvant chemotherapy were analyzed using β-catenin and GS immunostaining.
  
  
  RESULTS
  We detected nuclear β-catenin immunostaining in nearly all untreated HBs, including in fetal and embryonal epithelial components and in mesenchymal elements. We also observed diffuse GS expression in the epithelial component; however, it was frequently absent in embryonal and mesenchymal areas. In HBs resected after neoadjuvant chemotherapy, we recognized four histological patterns: fetal, hepatocellular-carcinoma-like, clear-cell, and normal-liver-like. All these patterns displayed diffuse GS expression. Fetal pattern showed diffuse nuclear β-catenin immunostaining. Nuclear β-catenin immunostaining was weak in the hepatocellular-carcinoma-like and clear-cell patterns. In normal-liver-like area, β-catenin expression was only located in the cell membrane.
  
  
  CONCLUSIONS
  The results suggest that nuclear β-catenin expression and diffuse GS immunostaining are the hallmarks of HB. Although epithelial and mesenchymal components of HB display nuclear β-catenin staining, this expression is attenuated following chemotherapy-induced cell maturation. GS immunostaining is especially useful for the assessment of section margins after neoadjuvant chemotherapy.
authors.affiliation: Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan; Department of Oral Hygiene, Hsin-Sheng College of Medical Care and Management, Taoyuan, Taiwan.
authors.forename: Wei-Ju
authors.initials: WJ
authors.lastname: Huang
authors.affiliation: Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: Jia-Huei
authors.initials: JH
authors.lastname: Tsai
authors.affiliation: Graduate Institute of Pathology, National Taiwan University, Taipei, Taiwan; Department of Pathology, National Taiwan University Hospital, Taipei, Taiwan. Electronic address: mrna0912@yahoo.com.tw.
authors.forename: Yung-Ming
authors.initials: YM
authors.lastname: Jeng
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D005974:Glutamate-Ammonia Ligase / Q000032:analysis*; D018197:Hepatoblastoma / Q000175:diagnosis* / Q000188:drug therapy; D006801:Humans; D007150:Immunohistochemistry; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000188:drug therapy; D051176:beta Catenin / Q000032:analysis*
chemical_list: D014408:Biomarkers, Tumor; C495270:CTNNB1 protein, human; D051176:beta Catenin; D005974:Glutamate-Ammonia Ligase
keywords: glutamine synthetase; hepatoblastoma; β-catenin