Blood Pressure Drug Boosts Lung Cancer Treatment
A blood pressure drug may make a type of lung cancer treatment more effective, a new study suggests.
Almost 2 million people are diagnosed with lung cancer every year worldwide and it is top killer form of the disease worldwide.
A team of scientists from England and China looked at the lung cancer drug called erlotinib, which can be used in an estimated 10 to 30 percent of patients who have a particular genetic mutation.
This mutation is on a particular receptor, or docking site, on the cancer cells that is crucial to the cell’s growth and survival. In patients with it, the drug blocks this mutated receptor and halts cell growth. Unfortunately, the cancer cells usually become resistant to the drug within a few months.
Previous studies have found that, in at least half of cases, the cancer cells become resistant to erlotinib by developing a second mutation. But until now scientists only partially understood how this second mutation allowed the cancer cells to protect themselves against erlotinib.
The researchers found this second mutation lowers levels of a naturally occurring antioxidant called glutathione. They also 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.
Spurred on by their finding, the team then looked for any other medicines that have been shown to raise glutathione levels. They found the ‘water pill’ ethacrynic acid, a diuretic used for 30 years to treat swelling, fluid retention and high blood pressure, raised glutathione levels. Ethacrynic acid works by triggering 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 researchers are now considering going ahead with human trials.
The study appears in Cell Discovery.