NDRG1 Is Necessary for p53-dependent Apoptosis

Although a number of target genes for the tumor suppressor p53 have been described, the mechanism of p53-dependent apoptosis is incompletely understood. Thus, it is essential to identify and characterize additional target genes that could mediate apoptosis. In the study reported here, we isolated a p53-regulated gene named NDRG1 ( N -Myc d own- r egulated g ene 1 ). Its expression is induced by DNA damage in a p53-dependent fashion. The promoter region of the NDRG1 gene contains a p53 binding site that confers p53-dependent transcriptional activation via a heterologous reporter. RNA interference and inducible gene expression approaches suggest that NDRG1 is necessary but not sufficient for p53-mediated caspase activation and apoptosis. This report further supports the notion that p53 controls a network of genes that are required for its apoptotic function.