title: Low expression of p63 and p73 in osteosarcoma.
abstract: BACKGROUND
  The recent discovery of two p53-related genes, p63 and p73, has revealed an additional level of complexity to the study of p53 function. Both genes encode multiple proteins arising from alternative promoter usage and splicing, with transactivation, DNA-binding, and tetramerization domains. Recent data support a role for p63 in squamous and transitional cell carcinomas, as well as in certain lymphomas and thymomas.
  
  
  METHODS
  To characterize the involvement of p63 and p73 in the development of osteosarcoma, we analyzed the expression and mutation of TAp63 and TAp73 in six osteosarcoma cell lines and twelve osteosarcoma specimens.
  
  
  RESULTS
  Semiquantitative DNA/PCR analysis revealed that eight (67%) and six (50%) out of twelve osteosarcoma specimens showed significantly reduced levels of p63 and p73 transcription, respectively. Direct sequencing of the entire coding region detected no mutations in cell lines or osteosarcoma specimens.
  
  
  CONCLUSIONS
  Our data suggest that low expression of p63 and p73 is relatively common in osteosarcomas and might contribute to their molecular pathogenesis.
authors.affiliation: Department of Pathology, College of Medicine, Hallym University, Anyang, Korea.
authors.forename: Hye-Rim
authors.initials: HR
authors.lastname: Park
authors.forename: Youn-Wha
authors.initials: YW
authors.lastname: Kim
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Park
authors.forename: Young-Hee
authors.initials: YH
authors.lastname: Maeng
authors.forename: Takayuki
authors.initials: T
authors.lastname: Nojima
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashimoto
authors.forename: Yong-Koo
authors.initials: YK
authors.lastname: Park
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis*; D001859:Bone Neoplasms / Q000737:chemistry*; D004273:DNA, Neoplasm / Q000032:analysis*; D004268:DNA-Binding Proteins / Q000032:analysis*; D015536:Down-Regulation; D015972:Gene Expression Regulation, Neoplastic; D016147:Genes, Tumor Suppressor; D006801:Humans; D009687:Nuclear Proteins / Q000032:analysis*; D012516:Osteosarcoma / Q000737:chemistry*; D010750:Phosphoproteins / Q000032:analysis*; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D015534:Trans-Activators / Q000032:analysis*; D014157:Transcription Factors; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D010750:Phosphoproteins; C115051:TP63 protein, human; C000606460:TP73 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D000072160:Tumor Protein p73; D025521:Tumor Suppressor Proteins