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Updated: Oct 1, 2025
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Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
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Partial p53 reactivation is sufficient to induce cancer regression
Boris Klimovich1, Laura Meyer1, Nastasja Merle1
1Institute of Molecular Oncology, Universities of Giessen and Marburg Lung Center (UGMLC), Philipps-University, Marburg, Germany.
Journal of Experimental & Clinical Cancer Research : CR
|March 2, 2022
Summary
Even partial reactivation of the tumor suppressor p53 (p53) can inhibit cancer growth. This study shows that low-level p53 activity is detrimental to p53-deficient cancers, suggesting incomplete reactivation may be a viable therapeutic strategy.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Impaired p53 (p53) function is a hallmark of cancer, and cancer cells often depend on this deficiency.
- Developing therapies to reactivate p53 is a promising strategy, but the required level of activity is unclear.
Purpose of the Study:
- To investigate the therapeutic potential of partially reactivated p53 (p53) in cancer.
- To determine if reduced p53 (p53) activity can inhibit tumor growth.
Main Methods:
- Generated knock-in mice with inducible expression of a partially functional p53 (p53) variant (E177R).
- Created mouse models of p53-deficient (p53) leukemia and lymphoma.
- Activated E177R expression post-cancer manifestation and assessed therapeutic response in vivo and in vitro.
Main Results:
- The p53 (p53) variant E177R inhibited proliferation and viability of p53-deficient (p53) leukemia and lymphoma.
- E177R expression triggered cancer regression, immune cell infiltration, and senescence in vivo.
- p53-deficient (p53) cancer cells demonstrated addiction to p53 (p53) absence, making them susceptible to even low-level p53 (p53) activity.
Conclusions:
- Partial loss-of-function p53 (p53) variants can have context-dependent effects, promoting or inhibiting tumorigenesis.
- Cancer cells are highly sensitive to p53 (p53) activity levels, with changes in activity being more critical than absolute levels.
- Incomplete p53 (p53) reactivation may be sufficient for a therapeutic effect, supporting drug development efforts.
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