A study conducted by the Cancer Research UK Radiation Research Centre, Oxford, has revealed that anti-malaria drug atovaquone can help radiotherapy to destroy malignant tumours.
The atovaquone drug is used both for the treatment and prevention of malaria, and is usually prescribed to travellers as malarone, which is a combination of atovaquone and proguanil.
The Cancer Research UK-funded investigation studied the effect of atovaquone on tumours with low oxygen levels within mice in a bid to discover if the drug can be repurposed to treat cancer.
Radiotherapy helps treat cancer by damaging the DNA in cells. A good supply of oxygen in the patient’s body reduces the ability of the cancer cells to repair broken DNA.
Therefore, a tumour with low levels of oxygen can repair itself more easily after radiotherapy.
This means that tumours with low oxygen levels are more difficult to treat successfully with radiotherapy. They are also more likely to spread to other parts of the body.
Cancer Research UK / Medical Research Council Institute for Radiation Oncology Oxford lead author Gillies McKenna said: “We hope that this existing low-cost drug will mean that resistant tumours can be re-sensitised to radiotherapy. We’re using a drug that we already know is safe.”
The new study has, for the first time, demonstrated how an anti-malaria drug slows down the rate that cancer cells use oxygen by targeting the mitochondria, the powerhouses of the cell that produce energy with the help of oxygen.
Atovaquone helps reverse the low-oxygen levels in almost all of the tumours by slowing down the use of oxygen to generate energy, thereby making the fully-oxygenated tumours become easily destroyed by radiotherapy.
The anti-malaria drug can be used to treat several types of cancers such as lung, brain, bowel, and head and neck cancer.
Image: Anti-malaria drug atovaquone can be used to treat a wide range of cancers. Photo: courtesy of Cancer Research UK.