Tumor protein p53 pathway regulators (p53 pathway regulators)

The Tumor protein p53 (TP53) pathway regulators consist of a complex network of proteins that govern the stability and activity of the tumor suppressor protein p53, often referred to as the guardian of the genome [1, 4]. In healthy cells, p53 levels are strictly maintained at low levels primarily through the action of MDM2, an E3 ubiquitin ligase that promotes p53 degradation via the proteasome [2, 5]. Upon sensing cellular stresses such as DNA damage, hypoxia, or oncogenic signaling, the regulatory network shifts to stabilize p53, allowing it to act as a master transcription factor [4]. Once activated, p53 triggers the expression of genes that mediate cell cycle arrest, DNA repair, senescence, or apoptosis to maintain genomic integrity [1, 3]. In many human cancers, the p53 pathway is compromised either through direct mutations in the TP53 gene or through the overexpression of negative regulators like MDM2 and MDMX [3, 5]. Pharmacological intervention in this pathway is a major area of oncology research, focusing on two primary strategies: the use of small-molecule inhibitors (e.g., Nutlins) to block the MDM2-p53 interaction in wild-type TP53 tumors, and the development of compounds like Eprenetapopt that can refold or reactivate mutant p53 proteins [5]. While promising, these therapies face challenges such as hematologic toxicities (e.g., thrombocytopenia) and the potential for tumors to develop resistance through the acquisition of new TP53 mutations [5]. Sources: [1] UniProt P04637 (TP53); [2] UniProt Q00987 (MDM2); [3] NIH/NCI Cancer Terms; [4] Levine, A. J. (2020). The p53 pathway: origins, node, and outcomes. Genes & Development; [5] Konopleva, M., et al. (2020). Targeting the MDM2-p53 protein-protein interaction for cancer therapy. Nature Reviews Clinical Oncology.

Other names

p53 signaling pathwayMDM2-p53 axisp53 regulatory networkTP53 pathway components

Inhibition of the MDM2-p53 protein-protein interaction to stabilize wild-type p53; covalent binding to mutant p53 to restore wild-type conformation and transcriptional activity.