A new study done at KU Leuven, Belgium, found that some antibiotics can be effective against melanoma. Melanoma is a form of skin cancer that begins in the cells responsible for the levels of pigment in the skin. The findings of the study were published in the Journal of Experimental Medicine.
Tumour cells become vulnerable after cancer therapy. The study has found that antibiotics exploit the vulnerability of these tumour cells.
“As the cancer evolves, some melanoma cells may escape the treatment and stop proliferating to ‘hide’ from the immune system. These are the cells that have the potential to form a new tumour mass at a later stage” explains cancer researcher and RNA biologist Eleonora Leucci (KU Leuven).
“In order to survive the cancer treatment however, those inactive cells need to keep their ‘power plants’ – the mitochondria – switched on at all times’ ‘. As mitochondria derived from bacteria that, over time, started living inside cells, they are very vulnerable to a specific class of antibiotics. This is what gave us the idea to use these antibiotics as anti-melanoma agents.“
The antibiotics used for the research are no longer in use against bacterial infections. This is because of the increasing antibiotic resistance. Leucci added that cancer cells showed greater sensitivity to the antibiotics used in the study and that they can be repurposed to be used against cancer.
Patient-derived tumours were implanted into mice and they were then treated with antibiotics. The antibiotics were either given as the only treatment or in a combination.Leucci added, “The antibiotics quickly killed many cancer cells and could thus be used to buy the precious time needed for immunotherapy to kick in. In tumours that were no longer responding to targeted therapies, the antibiotics extended the lifespan of – and in some cases even cured – the mice.”
However, researchers warned melanoma patients against the use of these antibiotics as the study mentioned only one human case. “Our findings are based on research in mice, so we don’t know how effective this treatment is in human beings. Our study mentions only one human case where a melanoma patient received antibiotics to treat a bacterial infection, and this re-sensitised a resistant melanoma lesion to standard therapy. This result is cause for optimism, but we need more research and clinical studies to examine the use of antibiotics to treat cancer patients. Together with oncologist Oliver Bechter (KU Leuven/UZ Leuven), who is a co-author of this study, we are currently exploring our options,” said Leucci.