Some antibiotics have shown promising results in fighting melanoma, a form of skin cancer, researchers from the university of Leuven report.
The research was carried out on mice, using tumour cells taken from human patients.
The testing relied on a tactic used by melanoma cells to resist cancer treatments: they stop multiplying in an effort to escape detection by the treatment. If successful, that allows them to regroup when the treatment stops, and create a new cancer.
“But in order to survive the cancer treatment, those inactive cells have to keep their ‘energy factories’ – the mitochondria – running all the time,” explained researcher and RNA biologist Eleonora Leucci.
“Since mitochondria are descended from bacteria that have come to live in cells over time, they are very vulnerable to a specific type of antibiotic. That gave us the idea to use these antibiotics as a remedy for melanoma.”
Tumour cells from patients were implanted into mice, which were then treated either with antibiotics alone or in combination with existing melanoma treatments.
“The antibiotics quickly killed many cancer cells and could therefore be used to gain valuable time: the time it takes for immunotherapy to take effect. In tumours that stopped responding to therapies, the antibiotics extended the mice’s lifespan — and in some cases, the mice even healed.”
A side-benefit of the research could be the revival of the usefulness of antibiotics that are no longer in use because of growing resistance to their effects. In this sort of application, that makes no difference.
“The cancer cells appear to be very sensitive to these antibiotics. We can therefore start to use the antibiotics as a medicine against cancer instead of against bacterial infections.”
But she warned patients not to improvise treatments on their own.
“Our findings are based on studies in mice, so we don’t know how effective this treatment is in humans,” she said.
The study does in fact report one case involving a human. A melanoma patient was given antibiotics to treat a bacterial infection, and this caused a resistant melanoma to respond again to standard treatment.
“This result is encouraging, but more research and more clinical studies are needed to study the use of antibiotics as a cancer treatment. Together with oncologist Oliver Bechter (KU Leuven), who is co-author of this study, we are exploring our options.”
The study, published in the Journal of Experimental Medicine, was funded by, among others, Kom op tegen Kanker, the Melanoma Research Alliance and the Flemish government’s Fund for Scientific Research (FWO).