Abstract
The tumor protein 53 (TP53) tumor suppressor gene is the most frequently somatically altered gene in human cancers. Here we show expression of N-Myc down-regulated gene 1 (NDRG1) is induced by p53 during physiologic low proliferative states, and mediates centrosome homeostasis, thus maintaining genome stability. When placed in physiologic low-proliferating conditions, human TP53 null cells fail to increase expression of NDRG1 compared with isogenic wild-type controls and TP53 R248W knockin cells. Overexpression and RNA interference studies demonstrate that NDRG1 regulates centrosome number and amplification. Mechanistically, NDRG1 physically associates with γ-tubulin, a key component of the centrosome, with reduced association in p53 null cells. Strikingly, TP53 homozygous loss was mutually exclusive of NDRG1 overexpression in over 96% of human cancers, supporting the broad applicability of these results. Our study elucidates a mechanism of how TP53 loss leads to abnormal centrosome numbers and genomic instability mediated by NDRG1.