Role of beta-catenin in hepatocarcinogenesis of rats.
BACKGROUND
Beta-catenin has two distinct roles in E-cadherin mediated cell adhesion and carcinogenesis by activating the wnt/beta-catenin signaling pathway. One occurs at the cell-adhesion site, where cadherins are linked to the actin-based cytoskeleton. The other takes place in the cytoplasm and nuclei and is thought to regulate cell transformation. We studied the role of beta-catenin in hepatocarcinogenesis of rats.


METHODS
Fresh liver specimens were obtained from normal rats, and atypical hyperplasia livers and hepatocarcinoma tissues from model rats. The changes of beta-catenin in gene expression levels were detected by reverse transcriptase polymerase chain reaction (RT-PCR) in the different specimens separately. At the same time, their localization was observed immunohistochemically.


RESULTS
In the normal liver specimens, beta-catenin staining was seen in the cell membrane. In liver specimens of atypical hyperplasia, beta-catenin staining occurred in the cell cytoplasm of some cells as well as in the cell membrane of others. Immunohistochemically cancerous tissues showed the presence of beta-catenin in the cytoplasm and nuclei. RT-PCR revealed that the gene expression levels of beta-catenin were same in all samples.


CONCLUSIONS
The accumulation of beta-catenin in the cytoplasm and/or nuclei frequently occurs in hepatocarcinogenesis of rats. It may be an early event in the development of hepatocarcinoma of rats.
Wang
Qi-Ming
QM
Department of Human Anatomy, Huaxi Medical Centre of Sichuan University, Chengdu 610041, China. wangqiming-6@163.com
Yang
Kai-Ming
KM
Zhou
Hong-Ying
HY
Yu
Zhen-Hai
ZH
Li
Xiao
X
Yang
Hui-Jun
HJ
D000818:Animals; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D018450:Disease Progression; D015972:Gene Expression Regulation, Neoplastic; D007150:Immunohistochemistry; D008114:Liver Neoplasms, Experimental / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D012334:RNA, Neoplasm / Q000235:genetics*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051176:beta Catenin / Q000235:genetics* / Q000378:metabolism
D012334:RNA, Neoplasm; D051176:beta Catenin