A blood pressure drug may make a type of lung cancer treatment more effective, suggests a new study conducted on human cells in the lab and on mice. The study results were published in the journal Cell Discovery.
The team studied a lung cancer drug called erlotinib which can be used to treat between 10 and 30 per cent of lung cancer patients.
Unfortunately, the drug usually stops working within a few months, due to cancer cells developing resistance to the treatment. In the current study the team showed that the resistance could be reversed using a simple and cheap diuretic, or ‘water pill’, called ethacrynic acid.
Almost 2 million people are diagnosed with lung cancer every year worldwide and it is the top international cancer killer. The drug erlotinib is prescribed to between 10 – 30 per cent of patients with non-small cell lung cancer, which accounts for 85 per cent of all lung cancer cases.
Previous studies have found that, in at least half of cases, the cancer cells become resistant to erlotinib by developing a second mutation.
In the latest study, the international team revealed new insights into how this additional mutation leads to resistance, opening avenues for new treatments.
The scientists found this second mutation lowers levels of a naturally-occurring antioxidant called glutathione.
The team found that if they raised glutathione levels in cancer cells in the lab, they reversed resistance to the drug erlotinib, and the treatment was once again able to kill cancer cells.
Researchers also found that the ‘water pill’ ethacrynic acid, raised glutathione levels. Ethacrynic acid triggers the kidneys to remove more water from the body but also blocks the breakdown of glutathione.
Mouse studies then confirmed that using the diuretic alongside the cancer drug erlotinib reversed resistance to the drug, and enabled it to kill lung cancer cells.
The team is now considering the possibility of translating their findings to human trials