title: Reacquisition of E-cadherin expression in metastatic deposits of signet-ring cell carcinoma of the upper gastrointestinal system: a potential anchor for metastatic deposition.
abstract: OBJECTIVE
  To examine the expression of E-cadherin in paired primary and metastatic signet-ring cell carcinomas (SRCC) of various organ systems in order to explore the potential role of the molecule in metastatic dissemination of this unique tumour type.
  
  
  METHODS
  Thirty-seven consecutive cases of SRCC from various organs with paired primary and metastatic tumorous tissue available were retrieved. The intensity of membranous E-cadherin expression was semiquantitatively scored on a scale of 0-3+.
  
  
  RESULTS
  Reduced E-cadherin expression was a distinct feature of primary SRCC and was observed in 78% of primary tumours. Interestingly, the E-cadherin reduction was less frequently seen in metastatic SRCC when compared with their primary counterparts, and was only found in 57% of tumours in lymph node metastases or at distant sites of relapse. Furthermore, the mean score of E-cadherin expression of primary SRCC was significantly lower than that of their metastatic counterparts (2.3 vs 1.8; p=0.008). When divided by organ systems, the reacquisition of E-cadherin expression in the metastatic deposits was most remarkable in the SRCC of upper gastrointestinal tract origin (2.3 vs 1.4; p=0.003), whereas no significant difference was observed in other organ systems.
  
  
  CONCLUSIONS
  While the reduction of E-cadherin in primary SRCC supports its pivotal role in epithelial-mesenchymal transition, a process crucial in tumour progression and metastatic dissemination, the re-expression of this molecule in metastatic SRCC cells implies a reversal to their epithelial phenotype (thus mesenchymal-epithelial transition) which, in turn, theoretically helps tumour cells to anchor and form cohesive metastatic deposits.
authors.affiliation: Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Yihong R
authors.initials: YR
authors.lastname: Ma
authors.affiliation: Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Gene P
authors.initials: GP
authors.lastname: Siegal
authors.affiliation: Department of Pathology, The University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Shi
authors.initials: S
authors.lastname: Wei
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015820:Cadherins / Q000378:metabolism*; D018279:Carcinoma, Signet Ring Cell / Q000378:metabolism*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000378:metabolism
chemical_list: D015820:Cadherins
keywords: CARCINOMA; CELL ADHESION MOLECULES; GASTRIC CANCER