title: The relationship among PDX1, CDX2, and mucin profiles in gastric carcinomas; correlations with clinicopathologic parameters.
abstract: OBJECTIVE
  Several studies performed on pancreatic-duodenal homeobox 1 (PDX1) have demonstrated a loss of expression and negative tumor modulator effect in gastric carcinoma. Relations between PDX1 and gastric metaplasia, differentiated type of gastric carcinoma, and the early stage of the disease have been exhibited in previous reports. The aim of this study was to examine expressions of PDX1, caudal type homeobox 2 (CDX2) and mucin (MUC) profiles to address the role of PDX1 in gastric carcinogenesis and its relationship with CDX2.
  
  
  METHODS
  Seventy gastrectomy specimens were analyzed immunohistochemically for PDX1, CDX2, MUC2, MUC5AC, and MUC6 expressions. The sum of cytoplasmic and nuclear PDX1 immunostaining and PDX1 positivity were assessed. All of the antibodies were examined for a correlation with tumor type, clinicopathologic parameters, and metaplasias. The relation of Ki-67 proliferation index with the expression profiles was also investigated.
  
  
  RESULTS
  Neither PDX1 (66/70) nor CDX2 (37/70) and the mucin profiles (MUC2:11/70, MUC5AC:48/70, MUC6:41/70) showed a significant difference between differentiated and undifferentiated types of gastric carcinoma and clinicopathologic parameters. The PDX1 expression frequency was 94.3%, with an average PDX1 score of 8.8 ± 4.2. PDX1 and CDX2 expression showed a significant difference (P = 0.026 and P = 0.002, respectively) among the phenotypic classification of gastric carcinomas. All of the gastric and intestinal mixed-phenotype gastric carcinomas (GI-type) showed both PDX1 and CDX2 immunopositivity. Except for the relation of PDX1 score with MUC6 expression, no significant difference was detected between PDX1 and CDX2, MUC2, and MUC5AC expressions. A relationship between CDX2 and MUC2 and also between MUC5AC and MUC6 was found statistically. The Ki-67 proliferation index revealed a significant positive correlation with PDX1, CDX2, and MUC2 positivity.
  
  
  CONCLUSIONS
  PDX1 expression revealed a higher positivity in gastric carcinomas than the previous studies and showed no relation with tumor type, clinicopathologic parameters, CDX2 expression, or mucin profiles. However, a significant relation of PDX1 and CDX2 expressions among phenotypic classification of gastric carcinomas reveals an idea about similar functions for PDX1 and CDX2 in the evolution of gastric carcinoma.
authors: Department of Pathology, Trakya University Medical Faculty, Edirne, Turkey. fulyapuyan@gmail.com
authors: Fulya
authors: F
authors: Oz Puyan
authors: Nuray
authors: N
authors: Can
authors: Filiz
authors: F
authors: Ozyilmaz
authors: Ufuk
authors: U
authors: Usta
authors: Necdet
authors: N
authors: Sut
authors: Ebru
authors: E
authors: Tastekin
authors: Semsi
authors: S
authors: Altaner
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000071616:CDX2 Transcription Factor; D005260:Female; D018398:Homeodomain Proteins / Q000032:analysis / Q000502:physiology*; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000032:analysis; D008297:Male; D008875:Middle Aged; D055271:Mucin 5AC / Q000032:analysis / Q000502:physiology; D055262:Mucin-2 / Q000032:analysis / Q000502:physiology; D055272:Mucin-6 / Q000032:analysis / Q000502:physiology; D009077:Mucins / Q000032:analysis / Q000502:physiology*; D010641:Phenotype; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000473:pathology; D015534:Trans-Activators / Q000032:analysis / Q000502:physiology*
chemical_list: D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; D019394:Ki-67 Antigen; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; C524734:MUC6 protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D055272:Mucin-6; D009077:Mucins; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein