title: Down-regulation of p73 correlates with high histological grade in Japanese with breast carcinomas.
abstract: BACKGROUND
  p73, a homologue of p53, has been located at chromosome 1p36-33, a region of frequently observed loss of heterozygosity in breast cancers. The objective of the present study was to investigate the function of p73 in Japanese with breast cancers.
  
  
  METHODS
  Sixty Japanese patients with breast cancer were assessed by polymerase chain reaction single strand confirmation polymorphism analysis and direct sequencing to detect the p73 allele. p73 mRNA levels were also determined in 40 out of 60 patients by reverse-transcriptional polymerase chain reaction.
  
  
  RESULTS
  We analyzed the entire open reading frame of the p73 gene by polymerase chain reaction single strand confirmation polymorphism and sequencing, and failed to identify any mutations of p73 in the encoding regions detected. Loss of heterozygosity of p73 was infrequent and only found in 9% of breast carcinomas. We revealed a few polymorphisms with a frequency of 13% - 29%, which had been reported previously. Down-regulation of p73 mRNA expression was observed in tumor tissues in comparison to the normal breast tissues. A significant inverse correlation was found between p73 transcripts and high histological grade, suggesting that down-regulated p73 expression could be related to poor prognosis in those patients.
  
  
  CONCLUSIONS
  Our results suggest that p73 may serve as a tumor suppressor gene and its expression plays a role in tumorigenesis in Japanese patients with breast cancer.
authors.affiliation: Department of Clinical Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong 505031, China.
authors.forename: Cai-wen
authors.initials: CW
authors.lastname: Du
authors.forename: Izo
authors.initials: I
authors.lastname: Kimijima
authors.forename: Toru
authors.initials: T
authors.lastname: Otake
authors.forename: Rikiya
authors.initials: R
authors.lastname: Abe
authors.forename: Seiichi
authors.initials: S
authors.lastname: Takenoshita
authors.forename: Guo-jun
authors.initials: GJ
authors.lastname: Zhang
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D019656:Loss of Heterozygosity / Q000235:genetics; D008875:Middle Aged; D009687:Nuclear Proteins / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C000606460:TP73 protein, human; D000072160:Tumor Protein p73; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins