p53 in cancer: ready for therapeutic targeting?

TP53 (p53) is one of the oldest and best studied genes implicated in cancer formation or progression. Although originally identified as an oncogene (1,2), it has been known for several decades that wild-type (WT) p53 functions as a tumor suppressor gene. Suppression of cancer formation involves the binding of p53 to specific DNA response elements, followed by the induction of genes involved in one or more of the following processes, apoptosis, cell cycle arrest, senescence, DNA repair, metabolism or reactive oxygen species (ROS) modulation (3). Because of its ability to prevent cancer formation, p53 has been referred to as the “Guardian of the Genome” (4).