Metabolic stress controls mutant p53 R248Q stability in acute myeloid leukemia cells

Area of Science:

• Molecular Biology
• Cancer Research
• Cellular Biology

Background:

• Mutant p53 (mt p53) proteins are frequently found in human cancers and contribute to tumor development.
• Eliminating mt p53 is a promising therapeutic strategy to improve cancer patient prognosis.
• Understanding the mechanisms of mt p53 degradation is crucial for developing targeted therapies.

Purpose of the Study:

• To investigate the mechanisms by which p53-R248Q, a common mt p53 mutant, is eliminated.
• To explore the role of autophagy pathways in mt p53 degradation under different metabolic conditions.
• To evaluate the potential of combining Hsp90 and PDK1 inhibitors for mt p53 targeting.

Main Methods:

• Utilized the Hsp90 inhibitor 17-AAG and the PDK1 inhibitor dichloroacetate (DCA).
• Assessed the impact of these inhibitors on macroautophagy and Chaperone-Mediated Autophagy (CMA) pathways.
• Quantified p53-R248Q levels and degradation under normal and metabolic stress conditions.

Main Results:

• 17-AAG promotes p53-R248Q degradation via macroautophagy under normal conditions.
• DCA induces p53-R248Q accumulation by inhibiting macroautophagy.
• Combined DCA and 17-AAG treatment enhances p53-R248Q degradation through CMA activation under metabolic stress.

Conclusions:

• Different metabolic contexts trigger distinct autophagy mechanisms for mt p53 degradation.
• Metabolic stress shifts p53-R248Q degradation towards CMA.
• Targeting both macroautophagy and CMA pathways offers a novel strategy for eliminating mt p53 in cancer.