title: Wdr66 is a novel marker for risk stratification and involved in epithelial-mesenchymal transition of esophageal squamous cell carcinoma.
abstract: BACKGROUND
  We attempted to identify novel biomarkers and therapeutic targets for esophageal squamous cell carcinoma by gene expression profiling of frozen esophageal squamous carcinoma specimens and examined the functional relevance of a newly discovered marker gene, WDR66.
  
  
  METHODS
  Laser capture microdissection technique was applied to collect the cells from well-defined tumor areas in collaboration with an experienced pathologist. Whole human gene expression profiling of frozen esophageal squamous carcinoma specimens (n = 10) and normal esophageal squamous tissue (n = 18) was performed using microarray technology. A gene encoding WDR66, WD repeat-containing protein 66 was significantly highly expressed in esophageal squamous carcinoma specimens. Microarray results were validated by quantitative real-time polymerase chain reaction (qRT-PCR) in a second and independent cohort (n = 71) consisting of esophageal squamous cell carcinoma (n = 25), normal esophagus (n = 11), esophageal adenocarcinoma (n = 13), gastric adenocarcinoma (n = 15) and colorectal cancers (n = 7). In order to understand WDR66's functional relevance siRNA-mediated knockdown was performed in a human esophageal squamous cell carcinoma cell line, KYSE520 and the effects of this treatment were then checked by another microarray analysis.
  
  
  RESULTS
  High WDR66 expression was significantly associated with poor overall survival (P = 0.031) of patients suffering from esophageal squamous carcinomas. Multivariate Cox regression analysis revealed that WDR66 expression remained an independent prognostic factor (P = 0.042). WDR66 knockdown by RNA interference resulted particularly in changes of the expression of membrane components. Expression of vimentin was down regulated in WDR66 knockdown cells while that of the tight junction protein occludin was markedly up regulated. Furthermore, siRNA-mediated knockdown of WDR66 resulted in suppression of cell growth and reduced cell motility.
  
  
  CONCLUSIONS
  WDR66 might be a useful biomarker for risk stratification of esophageal squamous carcinomas. WDR66 expression is likely to play an important role in esophageal squamous cell carcinoma growth and invasion as a positive modulator of epithelial-mesenchymal transition. Furthermore, due to its high expression and possible functional relevance, WDR66 might be a novel drug target for the treatment of squamous carcinoma.
authors.affiliation: Experimental Clinical Research Center at the Max-Delbrueck-Center for Molecular Medicine, Charité Campus Buch, Lindenbergerweg 80, Berlin, 13125, Germany.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.forename: Chenming
authors.initials: C
authors.lastname: Ma
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Kemmner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins / Q000235:genetics*; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D049109:Cell Proliferation; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics*; D004938:Esophageal Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D000077277:Esophageal Squamous Cell Carcinoma; D005260:Female; D015870:Gene Expression; D055785:Gene Knockdown Techniques; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D062793:Occludin / Q000235:genetics; D012306:Risk; D014746:Vimentin / Q000235:genetics; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D002135:Calcium-Binding Proteins; D062793:Occludin; D014746:Vimentin; C574720:WDR66 protein, human