ABSTRACT
It has been proposed that in the human liver, the estrogen receptor gene may become inappropriately expressed as a consequence of HBV integration, contributing to cell transformation. This study was undertaken to examine estrogen receptor status in patients with hepatitis B virus infection and to analyze the expression of progesterone receptor and of a heat-shock 27,000-D protein (hsp27), both of which are estrogen regulated in estrogen target tissues. Receptor proteins were detected in liver biopsy specimens by immunocytochemistry using antireceptor monoclonal antibodies; a monoclonal antibody was also used to detect hsp27. Estrogen receptor and progesterone receptor were mainly seen in the nuclei of hepatocytes. The presence of hepatitis B virus infection did not always result in elevated estrogen receptor expression, but in general the expression of this receptor protein was higher in hepatitis B virus-positive patients than in patients with the same pathological findings (hepatitis, cirrhosis, hepatocarcinoma) but without hepatitis B virus. This was more clearly seen in the patients with hepatitis. Although estrogen receptor expression was moderate to high in many samples, the expression of the two biochemical markers of estrogen action at postreceptor levels (progesterone receptor and hsp27) was low or absent in most of the liver tissues examined, suggesting that in the liver the interaction of estrogen-estrogen receptor-DNA has characteristics inherent to this tissue.
