Beta-catenin expression in intramucosal neoplastic lesions of the stomach. Comparative analysis of adenoma/dysplasia, adenocarcinoma and signet-ring cell carcinoma.
OBJECTIVE
To clarify roles of beta-catenin in the early stage of gastric tumorigenesis, we investigate beta-catenin expression in stomach intramucosal neoplasms.


METHODS
For immunohistochemistry, 84 gland-forming neoplasms and 17 signet-ring cell carcinomas were examined. The gland-forming neoplasms were grouped according to the Vienna classification: group A (low-grade adenoma/dysplasia), group B (high-grade adenoma/dysplasia) and group C (intramucosal carcinoma).


RESULTS
Strong nuclear expression was detected not only in group C (21.4%) but in groups A (20.8%) and B (11.2%). Strong cytoplasmic expression was detected in groups A, B and C: 16.7, 11.2 and 16.7%, respectively. Loss of membranous stainings (LOM) were also detected in groups A, B and C: 20.8, 22.2 and 31.0%, respectively. No significant difference was found among groups A, B and C with respect to nuclear, cytoplasmic, and membranous expression. Regarding signet-ring cell carcinomas, all cases were essentially negative for nuclear expression and 11.8% of the cases showed weak cytoplasmic expression as well as LOM. There were obvious differences between gland-forming adenocarcinoma and signet-ring cell carcinoma with respect to nuclear and cytoplasmic expression but not in terms of membranous expression.


CONCLUSIONS
These findings suggest that beta-catenin expression does not always reflect the malignant transformations in the early stage of gastric tumorigenesis.
Tsukashita
Shizuki
S
Department of Pathology, Shiga University of Medical Science, Setatsukinowa-cho, Otsu, Shiga 520-2192, Japan.
Kushima
Ryoji
R
Bamba
Masamichi
M
Nakamura
Etsuko
E
Mukaisho
Ken-ichi
K
Sugihara
Hiroyuki
H
Hattori
Takanori
T
D000236:Adenoma / Q000737:chemistry / Q000473:pathology; D002277:Carcinoma / Q000737:chemistry / Q000473:pathology; D002471:Cell Transformation, Neoplastic; D003598:Cytoskeletal Proteins / Q000032:analysis*; D005260:Female; D005753:Gastric Mucosa / Q000737:chemistry* / Q000473:pathology*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007725:Krukenberg Tumor / Q000737:chemistry / Q000473:pathology; D008297:Male; D010051:Ovarian Neoplasms / Q000737:chemistry / Q000473:pathology; D010641:Phenotype; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000473:pathology*; D015534:Trans-Activators / Q000032:analysis*; D051176:beta Catenin
C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D015534:Trans-Activators; D051176:beta Catenin