Alpha-catenin expression is decreased in patients with gastric carcinoma.
OBJECTIVE
To assess the expression of alpha-catenin in gastric carcinoma and to determine the role of alpha-catenin expression in gastric carcinogenesis.


METHODS
alpha-catenin expression was assessed by semi-quantitative reverse transcriptase-polymerase chain reaction and immunohistochemical staining in 49 gastric carcinomas, 26 adjacent non-cancerous mucosae, and gastric biopsy specimens from 11 healthy controls.


RESULTS
mRNA levels of alpha-catenin were reduced or absent in 34 of 49 (69%) gastric carcinoma tissues and in 5 of 26 (19%) tumor-free gastric mucosae of carcinoma patients, respectively. Of the carcinoma samples with altered alpha-catenin mRNA levels, alpha-catenin expression was negative in 20 and decreased in 14 cases. Up to 69% of tumors were stained abnormally for alpha-catenin. Of the 34 cases whose mRNA expression of alpha-catenin was reduced, 32 (94%) showed abnormal immunostaining patterns, while only 2 showed a normal alpha-catenin expression. The frequency of reduced expression of alpha-catenin mRNA was 14% in well-differentiated carcinomas, higher than that in poorly differentiated carcinomas (86%). A significant correlation was not shown between alpha-catenin expression and both depth of invasion and lymph node metastasis. Moreover, there was no statistical difference between loss or down-regulation of alpha-catenin mRNA and Helicobacter pylori (H. pylori) infection.


CONCLUSIONS
Downregulation of alpha-catenin expression is common in gastric carcinoma, and alpha-catenin expression may be used as a differentiation marker. Downregulation of alpha-catenin expression may be an early event in tumorigenesis. Reduced alpha-catenin expression is not correlated with H. pylori infection.
Zhou
Yong-Ning
YN
Department of Gastroenterology, First Hospital, Lanzhou University, Lanzhou 730000, Gansu Province, China. yongningzhou@sina.com.cn
Xu
Cai-Pu
CP
Chen
Yu
Y
Han
Biao
B
Yang
Shi-Ming
SM
Fang
Dian-Chun
DC
D000328:Adult; D000368:Aged; D003598:Cytoskeletal Proteins / Q000235:genetics* / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016481:Helicobacter Infections / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D013274:Stomach Neoplasms / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D051178:alpha Catenin
C495273:CTNNA1 protein, human; D003598:Cytoskeletal Proteins; D051178:alpha Catenin