Immunohistochemical location of prothymosin alpha in regenerating human hepatocytes and hepatocellular carcinomas.

In the present paper we analysed the presence of prothymosin alpha (ProT) in human liver. In normal liver, ProT immunostaining was found in the nuclei of bile duct cells, but not in the hepatocytes. In contrast an intense immunoreactivity was observed in regenerative hepatocytes of chronic hepatitis, cirrhosis and in hepatocellular carcinomas. In all cases the immunostaining was restricted to the nuclei, but the nucleoli were always negative. Similar results were obtained for proliferating cell nuclear antigen. These findings confirm that ProT is related to cell proliferation and provides a new immunohistochemical proliferation marker for routinely processed samples.