Anti-apoptotic protein TCTP controls the stability of the tumor suppressor p53

In this study, we identified p53 as a novel TCTP-interacting protein using TCTP as bait. Also, we determined the critical binding sites between TCTP and p53. To elucidate the functional consequence of the interaction, we developed the overexpression and inhibition system of TCTP and p53 expression. Overexpression of TCTP in lung carcinoma cells reversed p53 mediated apoptosis and inhibition of TCTP expression by small interfering RNA increased apoptosis of lung carcinoma cells. Moreover, it was observed that TCTP overexpression promotes degradation of p53. These results clearly indicate that the interaction between TCTP and p53 prevents apoptosis by destabilizing p53. Thus, TCTP acts as a negative regulator of apoptosis in lung cancer.