Expression of CARD6, an NF-kappaB activator, in gastric, colorectal and oesophageal cancers.
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.
Kim
Sung Soo
SS
Department of Pathology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Ahn
Chang Hyeok
CH
Kang
Mi Ran
MR
Kim
Yoo Ri
YR
Kim
Ho Shik
HS
Yoo
Nam Jin
NJ
Lee
Sug Hyung
SH
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
D014408:Biomarkers, Tumor; D053468:CARD Signaling Adaptor Proteins; C478017:CARD6 protein, human; D016328:NF-kappa B