Loss-of-Function but Not Gain-of-Function Properties of Mutant TP53 Are Critical for the Proliferation, Survival, and Metastasis of a Broad Range of Cancer Cells

Sep 21, 2026

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Mutations in the tumor suppressor TP53 drive cancer and can lead to poor responses to chemotherapy through reported loss-of-function (LOF), dominant-negative, and gain-of-function (GOF) activities, yet their relative importance has remained unclear. CRISPR/Cas9 removal of 12 TP53 mutants with reported GOFs showed no effect on proliferation or chemotherapeutic responses across 15 human cancer cell lines and colon cancer–derived organoids. Deleting mutant TP53/TRP53 also did not impair growth or metastasis in immune-deficient mice, nor growth of murine cancers in immune-competent models. DepMap mining similarly found no impact after removal of 158 TP53 mutants on 391 human cancer cell lines, whereas restoring wild-type TP53 eliminated growth in vitro, indicating LOF is critical for sustained expansion of many tumor types. This study supports targeting mutant TP53 GOF activities or blocking its expression as unlikely to yield therapeutic impact.

LanguageEnglish

CategoryResearch & Report

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Pages18

Reading Time45 min

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Abstract

Significance

Introduction

RESEARCH ARTICLE Loss-of-Function but Not Gain-of-Function Properties of Mutant TP53 Are Critical for the Proliferation, Survival, and Metastasis of a Broad Range of Cancer Cells Zilu Wang1,2, Matteo Burigotto3, Sabrina Ghetti3, François Vaillant1,2, Tao Tan1,2, Bianca D. Capaldo1,2, Michelle Palmieri1,2, Yumiko Hirokawa1,2, Lin Tai1, Daniel S. Simpson1,2, Catherine Chang1, Allan Shuai Huang1,2, Elizabeth Lieschke1,2, Sarah T. Diepstraten1,2, Deeksha Kaloni1,2, Chris Riffkin1, David C.S. Huang1,2, Connie S.N. Li Wai Suen1,2, Alexandra L. Garnham1,2, Peter Gibbs1,2, Jane E. Visvader1,2, Oliver M. Sieber1,2, Marco J. Herold1,2, Luca L. Fava3, Gemma L. Kelly1,2, and Andreas Strasser1,2 ABSTRACT Mutations in the tumor suppressor TP53 cause cancer and impart poor chemotherapeutic responses, reportedly through loss-of-function, dominant-negative effects and gain-of-function (GOF) activities. The relative contributions of these attributes is unknown. We found that removal of 12 different TP53 mutants with reported GOFs by CRISPR/Cas9 did not impact proliferation and response to chemotherapeutics of 15 human cancer cell lines and colon cancer–derived organoids in culture. Moreover, removal of mutant TP53/TRP53 did not impair growth or metastasis of human cancers in immune-deficient mice or growth of murine cancers in immune-competent mice. DepMap mining revealed that removal of 158 different TP53 mutants had no impact on the growth of 391 human cancer cell lines. In contrast, CRISPR-mediated restoration of wild-type TP53 extinguished the growth of human cancer cells in vitro. These findings demonstrate that LOF but not GOF effects of mutant TP53/TRP53 are critical to sustain expansion of many tumor types. SIGNIFICANCE: This study provides evidence that removal of mutant TP53, thereby deleting its reported GOF activities, does not impact the survival, proliferation, metastasis, or chemotherapy responses of cancer cells. Thus, approaches that abrogate expression of mutant TP53 or target its reported GOF activities are unlikely to exert therapeutic impact in cancer. See related commentary by Lane, p. 211. INTRODUCTION TP53/TRP53/p53 suppresses tumor development through oncogenic stress-induced transcriptional upregulation of genes involved in several cellular responses, including apoptotic cell death, cell-cycle arrest, cellular senescence, and DNA repair (1, 2) . Mutations in the TP53 gene are found in human cancers of diverse cellular origin with an overall frequency of approximately 50%, often occurring alongside loss of the other TP53 allele (loss of heterozygosity; LOH; ref. 3) . Although some of these mutations cause loss of the TP53 protein (modeled by Trp53 knockout mice), most TP53 mutations in human cancers result in substitution of single amino acids, usually in the DNA-binding domain. High levels of stabilized mutant TP53 proteins are a common feature of such malignant cells (4, 5) . Mutant TP53 proteins have been proposed to drive malignant transformation and sustain tumor growth via three not mutually exclusive processes: (i) loss-of-function (LOF), that is, an inability of 1The Walter and Eliza Hall Institute (WEHI), Melbourne, Australia. 2Department of Medical Biology, The University of Melbourne, Melbourne, Australia. 3Armenise-Harvard Laboratory of Cell Division, Department of Cellular, Computational and Integrative Biology – CIBIO, University of Trento, Trento, Italy. G.L. Kelly and A. Strasser are the co-senior authors of this article. Current address for M. Burigotto: Comprehensive Cancer Centre, School of Cancer & Pharmaceutical Sciences, King’s College London, London, United Kingdom and Organelle Dynamics Laboratory, The Francis Crick Institute, London, United Kingdom. Corresponding Authors: Andreas Strasser, Blood Cells and Blood Cancer, The Walter & Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, Victoria 3052, Australia. E-mail: [strasser@wehi.edu.au](strasser@

FAQs

What did the study test regarding mutant TP53 activities?

It assessed whether removing TP53 mutants with reported gain-of-function (GOF) properties changes proliferation, survival, metastasis, or chemotherapy responses.

How were mutant TP53 variants removed experimentally?

The study used CRISPR/Cas9 to delete 12 different TP53 mutants carrying reported GOFs and also evaluated additional TP53 mutant removal via DepMap mining.

What overall conclusion did the results support?

LOF effects of mutant TP53, rather than GOF activities, are critical for sustaining expansion of many tumor types; deleting mutant TP53 GOF activity did not significantly alter cancer behaviors or treatment responses.

Sep 21, 2026

Uploaded by Himbo