Immunohistochemical Expression of Glutathione S-Transferase pai in Hepatocellulae Carcinoma and Cholangiocarcinoma

Choi, Seok Reyol; Han, Sang Young; Son, Young Gi; Lee, Jong Hoon; Park, Hee Seung; Roh, Myung Hwan; Choi, Hong Jo; Huh, Gi Yeong

Abstract

BACKGROUND AND AIMS: It has been known that glutathione S-transferase n (GST-n ) is overexpressed in chemically induced precancerous or cancerous lesions of the hepatocyte in animal models. Unlike most results of animal models, however, there has been a controversy concerning the applica!ion of CST-n to human liver cancer as a tumor marker. Therefore, this study was carried out to evaluate the expression and the possibility of GST-n as an immunohistochemical marker in human hepatocellular carcinoma and cholangiocarcinoma.
METHODS
Labeled streptavidin biotin method after heat pretreatment with microwave oven was performed in formalin-fixed, paraffin- embedded tissue taken from wedge or needle biopsies from 16 cases of normal liver tissue, 20 hepatocellular carcinoma, and 20 cholangiocarcinoma, respectively.
RESULTS
The overexpression of GST-n was found in only three (15%) of 20 cases of hepatocellular carcinoma, but in sixteen (80%) of 20 cases of cholangiocarcinoma. The expression of GST-n in hepatocellular carcinoma showed a tendency to be increased with lower histology grade, but that in cholangiocarcinoma revealed a tendency to be decreased with lower histologic grade.
CONCLUSIONS
The results suggested that expression of CST-n would be an immunohistochemical marker of human cholangiocarcinoma, rather than hepatocellular carcinoma, unlike the results of GST-n expression during chemically induced animal hepatocarcinogenesis.