Mouse double minute 2 homolog–Tumor protein p53 protein–protein interface (MDM2–p53 PPI)

The MDM2–p53 protein–protein interface is a pivotal regulatory axis in cellular homeostasis and tumor suppression. Under normal conditions, the E3 ubiquitin ligase MDM2 (Mouse double minute 2 homolog) maintains low levels of the tumor suppressor protein p53 by binding to its N-terminal transactivation domain and targeting it for proteasomal degradation [UniProt: Q00987, P04637]. In many human cancers, particularly those retaining wild-type TP53, MDM2 is frequently overexpressed or amplified, effectively silencing the p53 pathway and promoting uncontrolled cell proliferation and survival [PubMed: 25213910]. Therapeutic intervention focuses on disrupting this specific interface using small-molecule inhibitors, often referred to as MDM2 antagonists, which occupy the hydrophobic pocket of MDM2 where p53 normally binds [PubMed: 14704432]. By blocking this interaction, these agents stabilize p53, leading to its accumulation and the subsequent activation of genes involved in cell cycle arrest, DNA repair, and apoptosis [PubMed: 30104654]. Clinical applications are primarily targeted at TP53 wild-type malignancies such as dedifferentiated liposarcoma and acute myeloid leukemia, where MDM2 inhibition can restore the endogenous tumor-suppressive capacity of the cell [PubMed: 33009411]. However, the clinical utility of these inhibitors is often limited by on-target hematological toxicities, most notably thrombocytopenia and neutropenia, resulting from p53 activation in normal bone marrow progenitor cells [PubMed: 28438744]. Emerging research also explores the potential for these inhibitors to prime the immune system or work synergistically with other targeted therapies [PubMed: 32884258].

Other names

MDM2-p53 interactionMDM2-p53 complexHDM2-p53 interfaceMDM2-p53 binding site

Small-molecule inhibition of the MDM2-p53 interaction to prevent p53 ubiquitination and degradation, thereby restoring p53-mediated tumor suppression.