title: Low expression of the snail gene is a good prognostic factor in node-negative invasive ductal carcinomas.
abstract: BACKGROUND
  While Snail is a zinc-finger transcription factor that triggers the epithelial-mesenchymal transition, it has also been reported to be indirectly regulated by estrogen receptor alpha (ERalpha) and to be involved in the transcriptional repression of the aromatase gene. The aim of the present study was to examine the role of Snail expression in node-negative invasive ductal carcinomas.
  
  
  METHODS
  We analyzed Snail mRNA expression levels in 86 node-negative invasive ductal carcinomas by real-time quantitative RT-PCR and studied whether Snail mRNA expression correlates with clinicopathological factors.
  
  
  RESULTS
  No correlation was found between Snail mRNA expression and ERalpha protein expression levels. However, we observed that none of the 34 patients showing low Snail mRNA expression developed distant metastasis while 6 of 52 (12%) showing high expression of Snail mRNA did. The level of Snail mRNA expression was not found to be significantly correlated with clinicopathological factors. No inverse correlation was found between the Snail and aromatase mRNA expression levels in our series.
  
  
  CONCLUSIONS
  Our data show that low expression of Snail mRNA is a good prognostic factor in node-negative invasive ductal carcinomas. Snail expression is suggested to be involved in distant metastasis in node-negative invasive ductal carcinomas.
authors.affiliation: Department of Breast Oncology, Aichi Cancer Center Hospital, Japan. toyamat-ncu@umin.ac.jp
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Toyama
authors.forename: Zhenhuan
authors.initials: Z
authors.lastname: Zhang
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Iwase
authors.forename: Hiroko
authors.initials: H
authors.lastname: Yamashita
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ando
authors.forename: Maho
authors.initials: M
authors.lastname: Hamaguchi
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Mizutani
authors.forename: Naoto
authors.initials: N
authors.lastname: Kondo
authors.forename: Takashi
authors.initials: T
authors.lastname: Fujita
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Fujii
authors.forename: Hiroji
authors.initials: H
authors.lastname: Iwata
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001141:Aromatase / Q000378:metabolism; D001943:Breast Neoplasms / Q000378:metabolism*; D015820:Cadherins / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism*; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D011379:Prognosis; D012333:RNA, Messenger / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism / Q000502:physiology
chemical_list: D015820:Cadherins; D047628:Estrogen Receptor alpha; D012333:RNA, Messenger; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D001141:Aromatase