Modulation of the gamma-secretase activity as a therapy against human hepatocellular carcinoma.

OBJECTIVE:Hepatocellular carcinoma (HCC) is the fifth most common tumor worldwide. The discovery of new therapies against HCC is highly dependable on finding molecules which play essential roles in cancer development. The objective of this study was to evaluate the activity of gamma secretase (γ-secretase), and the antitumor effects of a γ-secretase inhibitor (GSI) in HCC. METHODS:The expression of presenilin 1 (PS1), a core component of γ-secretase, was examined by Western blot. Activity of γ-secretase was measured by a luciferase-based reporter system, and cancer cells were transfected either with PS1 dominant negative mutant (PS1D385A) or treated with GSI. RESULTS:Expression of PS1 was increased in HCC tissue and several HCC cell lines, which were accompanied by elevated γ-secretase activity. Cell colony formation and cell proliferation were decreased upon treatment with GSI but not with PS1D385A transfection. CONCLUSION:GSIs may be appealing candidates for the development of new therapies against HCC.