Related Experiment Video

Updated: Jul 22, 2025

Yeast As a Chassis for Developing Functional Assays to Study Human P53
14:57

Yeast As a Chassis for Developing Functional Assays to Study Human P53

Published on: August 4, 2019

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p53 restoration in small cell lung cancer identifies a latent cyclophilin-dependent necrosis mechanism

Jonuelle Acosta1,2, Qinglan Li1, Nelson F Freeburg1,2

  • 1Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA.

Nature Communications
|July 21, 2023
PubMed

Insights

Restoring tumor suppressor p53 in small cell lung cancer (SCLC) triggers cell death, but the mechanism depends on tumor subtype. Cyclophilins control p53-induced necrosis, offering potential therapeutic targets for SCLC.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • The p53 tumor suppressor is crucial for preventing cancer but its role in small cell lung cancer (SCLC) is unclear.
  • p53 is frequently mutated in SCLC, yet its precise function in tumor suppression within this context remains largely unknown.

Purpose of the Study:

  • To investigate how p53 mediates tumor suppression in SCLC.
  • To explore the heterogeneity of p53's effects and identify molecular mechanisms driving cell death in SCLC.

Main Methods:

  • Utilized a conditional mouse model of SCLC with regulated p53 expression.
  • Analyzed tumor subtype heterogeneity and identified cyclophilins as key regulators.
  • Investigated the impact of cyclophilin inhibition on p53-mediated cell death.

Main Results:

  • SCLC tumors require p53 inactivation but exhibit heterogeneity in response to p53 reactivation.
  • p53 reactivation induces either senescence or necrosis depending on the tumor subtype.
  • Cyclophilins are essential for a p53-induced transcriptional program leading to necrosis in specific SCLC subtypes.
  • Inhibiting cyclophilin activity suppresses p53-mediated necrosis by modulating p53 transcriptional output.

Conclusions:

  • Intertumoral heterogeneity in SCLC dictates the cellular response to p53 restoration.
  • A cyclophilin-dependent mechanism regulates p53-induced necrosis in SCLC.
  • Targeting cyclophilins presents a potential therapeutic strategy for treating SCLC.

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