Expression of beta-catenin in hepatocellular carcinoma.
OBJECTIVE
The beta-catenin has been recognized as a critical member of the Wnt signaling pathway and plays an important role in the generation/differentiation of many tissues. Inappropriate activation of this pathway has been implicated in carcinogenesis. The mechanism underlying the development as well as its prognosis of hepatocellular carcinoma (HCC) has remained unclear. The purpose of this study is to analyze the expression of beta-catenin in HCC in relation to histological grades and viral hepatitis backgrounds.


METHODS
Thirty-two sections were selected at random from autopsy and surgical cases of HCC. Immunohistologically, the location and positivity of beta-catenin expression in HCC was examined.


RESULTS
Normal hepatocytes did not express beta-catenin. In 78% of HCC beta-catenin was expressed at the membrane of the cells, with or without cytoplasmic and/or nuclear expression. The tumor cells with well- and moderately-differentiated grades expressed frequently at the membrane and cytoplasm compared with poorly-differentiated type. Nuclear expression of beta-catenin was prone to occur in the tumor cells of poorly-differentiated grade. There were 15% of hepatitis C virus (HCV) backgrounds with nuclear expression. In contrast, there was 38% with nuclear expression in hepatitis B virus (HBV) backgrounds. In nonB-nonC hepatitis, no case expressed nuclear beta-catenin.


CONCLUSIONS
The beta-catenin expression in HCC cells was heterogeneous among types of hepatitis viral infection. Wnt signaling pathway might be deeply involved in less-differentiated HCC and HBV background.
Tien
Liem Thanh
LT
Department of Pathology, National Nagasaki Medical Center, 2-1001-1 Kubara, Omura, Nagasaki 856-8562, Japan.
Ito
Masahiro
M
Nakao
Mikiko
M
Niino
Daisuke
D
Serik
Meirmanov
M
Nakashima
Masahiro
M
Wen
Chun-Yang
CY
Yatsuhashi
Hiroshi
H
Ishibashi
Hiromi
H
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000473:pathology*; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D005260:Female; D006525:Hepatitis, Viral, Human / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism*; D051153:Wnt Proteins; D051176:beta Catenin
C495270:CTNNB1 protein, human; D003598:Cytoskeletal Proteins; D036341:Intercellular Signaling Peptides and Proteins; D015534:Trans-Activators; D051153:Wnt Proteins; D051176:beta Catenin