title: Expression of CARD6, an NF-kappaB activator, in gastric, colorectal and oesophageal cancers.
abstract: OBJECTIVE
  Activation of nuclear factor-kappa B (NF-kappaB) signalling is considered a crucial mechanism in the development of cancers. Caspase-associated recruitment domain 6 (CARD6) is a protein that activates NF-kappaB signalling evoked by RIP1, RIP2, Bcl-10 and MEKK. In this study, we analysed tissue expression of CARD6 protein in oesophageal squamous cell carcinoma (ESCC), gastric adenocarcinomas (GC) and colorectal adenocarcinomas (CRC).
  
  
  METHODS
  We analysed the expression of CARD6 protein in 58 ESCC, 100 GC and 103 CRC patients' tissues by immunohistochemistry using a tissue microarray (TMA) approach.
  
  
  RESULTS
  We found CARD6 immunostaining in cancer cells of ESCC (41/58; 70.7%), GC (45/100; 45.0%) and CRC (81/103; 78.6%). In the GC, intestinal-type GC (77.8%) showed higher expression of CARD6 than diffuse-type GC (20.0%) and mixed-type GC (50.0%). By contrast, corresponding normal epithelial cells of oesophagus (0%), stomach (8.0%) and colon (5.0%) displayed lower frequencies of CARD6 immunostaining. The CARD6 immunostaining was observed in nucleus/cytoplasm (ESCC) or cytoplasm (GC and CRC). The CARD6 expression was evident from an early TNM stage (stage I).
  
  
  CONCLUSIONS
  The increased expression of CARD6 in ESCC, GC and CRC tissues compared to their corresponding normal cells suggested that neoexpression of CARD6 might be related to activation of NF-kappaB pathway in the cancers and might play a role in the development of most types of gastrointestinal cancers.
authors.affiliation: Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
authors.forename: Sung Soo
authors.initials: SS
authors.lastname: Kim
authors.forename: Chang Hyeok
authors.initials: CH
authors.lastname: Ahn
authors.forename: Mi Ran
authors.initials: MR
authors.lastname: Kang
authors.forename: Yoo Ri
authors.initials: YR
authors.lastname: Kim
authors.forename: Ho Shik
authors.initials: HS
authors.lastname: Kim
authors.forename: Nam Jin
authors.initials: NJ
authors.lastname: Yoo
authors.forename: Sug Hyung
authors.initials: SH
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D053468:CARD Signaling Adaptor Proteins / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology; D002452:Cell Count; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D019085:Fluorescent Antibody Technique, Direct; D006801:Humans; D008297:Male; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism*; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D053468:CARD Signaling Adaptor Proteins; C478017:CARD6 protein, human; D016328:NF-kappa B