Fig. 4.
NDRG2 regulates the phosphorylation of GSK-3β. (A) NDRG2 introduction attenuated the increase of TCF/LEF activity following LiCl or β-catenin treatment. (B) Mutant NDRG2, NDRG2T334A and NDRG2Δ302 showed no effect on the transcription activity of TCF/LEF. (C) SW620/N was treated with NDRG2 siRNA. The reduction of NDRG2 mRNA and protein levels by siRNA was confirmed by RT–PCR and western blot analyses. The protein level of β-catenin was increased in the NDRG2 siRNA-introduced cells. (D) The suppression of LiCl-induced TCF activation by NDRG2 presented the possible function of NDRG2 in the regulation of GSK-3β activity, and the inhibitory phosphorylation of GSK-3β was reduced by NDRG2 overexpression. (E) Target genes of TCF/LEF transcription factor were downregulated following NDRG2 introduction.