The anti-malarial atovaquone increases radiosensitivity by alleviating tumour hypoxia.

Ashton TM., Fokas E., Kunz-Schughart LA., Folkes LK., Anbalagan S., Huether M., Kelly CJ., Pirovano G., Buffa FM., Hammond EM., Stratford M., Muschel RJ., Higgins GS., McKenna WG.

Tumour hypoxia renders cancer cells resistant to cancer therapy, resulting in markedly worse clinical outcomes. To find clinical candidate compounds that reduce hypoxia in tumours, we conduct a high-throughput screen for oxygen consumption rate (OCR) reduction and identify a number of drugs with this property. For this study we focus on the anti-malarial, atovaquone. Atovaquone rapidly decreases the OCR by more than 80% in a wide range of cancer cell lines at pharmacological concentrations. In addition, atovaquone eradicates hypoxia in FaDu, HCT116 and H1299 spheroids. Similarly, it reduces hypoxia in FaDu and HCT116 xenografts in nude mice, and causes a significant tumour growth delay when combined with radiation. Atovaquone is a ubiquinone analogue, and decreases the OCR by inhibiting mitochondrial complex III. We are now undertaking clinical studies to assess whether atovaquone reduces tumour hypoxia in patients, thereby increasing the efficacy of radiotherapy.

DOI

10.1038/ncomms12308

Type

Journal article

Journal

Nat Commun

Publication Date

25/07/2016

Volume

7

Keywords

Animals, Antimalarials, Atovaquone, Biguanides, Electron Transport Complex III, High-Throughput Screening Assays, Hypoxia-Inducible Factor 1, alpha Subunit, Mice, Inbred BALB C, Mice, Nude, Oxygen Consumption, Pyrimidines, Radiation Tolerance, Spheroids, Cellular, Tumor Cells, Cultured, Tumor Hypoxia

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