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Cell Cycle. 2012 Dec 1;11(23):4436-46. doi: 10.4161/cc.22778. Epub 2012 Nov 14.

Dietary downregulation of mutant p53 levels via glucose restriction: mechanisms and implications for tumor therapy.

Author information

1
Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC USA.

Abstract

The majority of human tumors express mutant forms of p53 at high levels, promoting gain of oncogenic functions and correlating with disease progression, resistance to therapy and unfavorable prognosis. p53 mutant accumulation in tumors is attributed to the ability to evade degradation by the proteasome, the only currently recognized machinery for p53 disruption. We report here that glucose restriction (GR) induces p53 mutant deacetylation, routing it for degradation via autophagy. Depletion of p53 leads, in turn, to robust autophagic activation and to cell death, while expression of degradation-defective mutant p53 blocks autophagy and enables survival to GR. Furthermore, we found that a carbohydrate-free dietetic regimen that lowers the fasting glucose levels blunts p53 mutant expression and oncogenic activity relative to a normal diet in several animal model systems. These findings indicate that the stability of mutant forms of p53 is influenced by the levels of glucose and by dietetic habits. They also unravel the existence of an inhibitory loop between autophagy and mutant p53 that can be exploited therapeutically.

PMID:
23151455
PMCID:
PMC3552926
DOI:
10.4161/cc.22778
[Indexed for MEDLINE]
Free PMC Article

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