Down-regulated expression of the TSAP6 protein in liver is associated with a transition from cirrhosis to hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) results from cirrhosis and, in Western Europe, hepatitis C virus and alcoholism are the predominant causes of this disease. We recently documented a global transcript repression in hepatocarcinoma nodules. The tumour suppressor activated pathway-6 (TSAP6) transcript codes for a transmembrane molecule that is an inducer of a caspase-3-dependent apoptotic pathway. The down-regulation of TSAP6 transcripts in HCC and perinodular cirrhosis, which contrasts with a sustained transcript level in HCC-free cirrhosis, has suggested that this hepatic protein level may provide a prognostic marker for HCC occurrence. This protein was quantified by semiquantitative assessment of immunohistochemistry on samples from 42 cases HCC-free cirrhosis, 49 cases cirrhosis with HCC, 43 HCC associated with healthy liver and 31 controls. TSAP6 expression was linked to the liver state, healthy or cirrhotic without or with an HCC and to tumour grade. With biopsies periodically performed for surveillance purposes, the decreased expression of TSAP6 in cirrhotic tissue could reflect a decrease in the apoptotic process and could be interpreted as a warning sign. This evaluation of the TSAP6 level in cirrhotic liver conveys predictive information for the development of HCC.