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Updated: Sep 17, 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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Restoring p53 wild-type conformation in TP53-Y220C-mutant acute myeloid leukemia
Bing Z Carter1, Po Yee Mak1, Edward Ayoub1
1Section of Molecular Hematology and Therapy, Department of Leukemia, The University of Texas MD Anderson Cancer Center, Houston, TX.
Blood
|July 3, 2025
Summary
TP53-Y220C mutations in acute myeloid leukemia (AML) create a pocket that PC14586 targets to restore p53 function. However, MDM2 and XPO1 limit apoptosis, which venetoclax can overcome, suggesting combination therapies for TP53-mutant leukemia.
Area of Science:
- Oncology
- Molecular Biology
- Cancer Genetics
Background:
- TP53-Y220C is a common mutation in acute myeloid leukemia (AML) and myelodysplastic syndromes, associated with poor prognosis.
- This mutation results in a structural pocket within the p53 protein, impacting its function.
- PC14586 is a novel small molecule designed to bind this pocket and restore wild-type p53 conformation.
Purpose of the Study:
- To investigate the mechanism by which PC14586 restores p53-WT conformation in TP53-Y220C AML.
- To identify factors limiting the efficacy of PC14586-induced apoptosis.
- To explore combination strategies for enhancing anti-leukemic effects in TP53-mutant AML.
Main Methods:
- Treatment of TP53-Y220C AML cell lines and patient samples with PC14586.
- Assessment of p53 conformation, transcriptional activity, and apoptosis induction.
- Investigated the roles of MDM2, XPO1, and BCL-2 family proteins.
- Utilized pharmacological inhibitors (MDM2, XPO1, venetoclax) and in vivo xenograft models.
Main Results:
- PC14586 successfully converted p53-Y220C to a p53-WT conformation and activated transcriptional targets.
- MDM2 induction and XPO1-mediated nuclear export limited p53 transcriptional activity and apoptosis.
- PC14586-reactivated p53-WT did not effectively bind anti-apoptotic BCL-2 family proteins.
- Co-treatment with venetoclax restored BCL-2 binding, induced massive cell death, and improved survival in vivo.
Conclusions:
- Transcription-dependent (MDM2, XPO1) and -independent (BCL-2 family interactions) mechanisms limit PC14586's apoptogenic activity in TP53-Y220C AML.
- Inhibition of MDM2, XPO1, or BCL-2 family proteins, particularly with venetoclax, can overcome these limitations.
- Combination therapies hold promise for optimizing apoptosis induction and treating TP53-mutant leukemias.
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