TP53 mutations in head and neck cancer cells determine the Warburg phenotypic switch creating metabolic vulnerabilities and therapeutic opportunities for stratified therapies.

Patients with mutated TP53 have been identified as having comparatively poor outcomes compared to those retaining wild-type p53 in many cancers, including squamous cell carcinomas of the head and neck (SCCHN). We have examined the role of p53 in regulation of metabolism in SCCHN cells and find that loss of p53 function determines the Warburg effect in these cells. Moreover, this metabolic adaptation to loss of p53 function creates an Achilles' heel for tumour cells that can be exploited for potential therapeutic benefit. Specifically, cells lacking normal wild-type p53 function, whether through mutation or RNAi-mediated downregulation, display a lack of metabolic flexibility, becoming more dependent on glycolysis and losing the ability to increase energy production from oxidative phosphorylation. Thus, cells that have compromised p53 function can be sensitised to ionizing radiation by pre-treatment with a glycolytic inhibitor. These results demonstrate the deterministic role of p53 in regulating energy metabolism and provide proof of principle evidence for an opportunity for patient stratification based on p53 status that can be exploited therapeutically using current standard of care treatment with ionising radiation. What is already known • TP53 mutations are the most common genetic mutation in many cancers, including head and neck cancers. •Patients with mutated p53 display poor prognosis but no method exists for selectively treating these patients What this study adds •We identify and confirm that p53 status (mutant or normal) determines tumour cell metabolic profile •Metabolic changes induced by loss of p53 function determine sensitivity to metabolic inhibition in combination with the mainstay of current therapy-radiation, and provide an opportunity to increase radiation sensitivity in p53 mutated cells •The results suggest that a strategy for treating patients with mutations in TP53 could be readily developed combining the current standard of care (radiotherapy) with short term inhibition of a metabolic pathway (glycolysis). [ABSTRACT FROM AUTHOR]