Differential SIRT1 expression in hepatocellular carcinomas and cholangiocarcinoma of the liver.

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are two major liver malignancies. Although some phenotypic overlap is known, HCC and CCA are usually different with regard to etiology, histology, and prognosis. Gene expression and deacetylase activity of the class III histone deacetylase SIRT1 are up-regulated in cancer cells due to oncogene overexpression or loss of function of tumor suppressor genes.