SeneSIQ›Mechanism
Mechanism

p53 / MDM2 axis

Reference definition for a cellular-senescence node.

Arrest control node

Definition

Category: Arrest control node

Also known as: p53, MDM2, p53-MDM2 interaction

p53 is the central stress-response transcription factor that induces p21 and helps establish senescence; MDM2 is its principal negative regulator, targeting p53 for degradation. Disrupting the p53/MDM2 interaction shifts the balance toward apoptosis in stressed cells — the mechanistic rationale for the senolytic UBX0101.

Key points

  • UBX0101 is a small-molecule inhibitor of the p53/MDM2 interaction, intended to push senescent cells into apoptosis.
  • The axis illustrates that senescence and apoptosis share upstream machinery — the basis of the 'transiently disable survival, tip into apoptosis' senolytic strategy.
  • In the knee-osteoarthritis Phase 2 trial this mechanism did not translate into clinical benefit (see study page).

Related interventions

Sourcing

UNITY Biotechnology UBX0101 mechanism disclosures; standard p53 biology reviews.

Reference synthesis (tier 4); verification: review_level_2026-07-12.