Stability of the LATS2 tumor suppressor gene is regulated by tristetraprolin.

LATS2 is a tumor suppressor gene implicated in the control of cell growth and the cell cycle. Here, we investigated the post-transcriptional regulation of LATS2 expression by tristetraprolin (TTP). Our results show that the expression level of LATS2 is inversely correlated with TTP expression in human cancer cell lines. Overexpression of TTP reduced the expression level of LATS2. Conversely, treatment with small interfering RNA against TTP increased the expression level of LATS2 through stabilization of LATS2 mRNA and suppressed the proliferation of A549 human lung cancer cells. LATS2 mRNA contains AU-rich elements (AREs) within the 3'-untranslated region, and TTP destabilized a luciferase mRNA containing LATS2 ARE. In addition, RNA electrophoretic mobility shift assay revealed that TTP directly bound to the ARE of LATS2 mRNA. These results establish LATS2 mRNA as a physiological target of TTP and suggest the possibility that TTP controls cell growth through regulation of LATS2 mRNA stability.