KU Leuven: Antibiotics may be a new weapon in the fight against melanomas
Researchers at KU Leuven may have found a new weapon in the fight against melanoma: antibiotics that attack the ‘energy factories’ of cancer cells. These antibiotics take advantage of a weakness that occurs when tumor cells try to survive cancer treatment.
As the cancer develops, some melanoma cells may escape treatment and stop multiplying to “hide” from the immune system. “These cells could later form a new tumor mass,” explains cancer researcher and RNA biologist Eleonora Leucci (KU Leuven). “But in order to survive the cancer treatment, those inactive cells have to keep their ‘energy factories’ – the mitochondria – running all the time. 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.”
The team implanted tumor cells from patients into mice, which were then treated with antibiotics, either as the sole treatment or in combination with existing anti-melanoma therapies. Leucci: “The antibiotics quickly killed many cancer cells and could therefore be used to save valuable time: the time it takes for immunotherapy to take effect. In tumors that stopped responding to therapies, the antibiotics extended the mice’s lifespan — and in some cases, the mice even healed.”
The researchers worked with antibiotics that are rarely used against bacterial infections due to increasing antibiotic resistance. However, this resistance has no effect on the effectiveness of the treatment in this study, explains Leucci. “The cancer cells appear to be very sensitive to these antibiotics. We can therefore start using the antibiotics as a medicine against cancer instead of against bacterial infections.”
Potential in the fight against cancer
However, melanoma patients should not start experimenting themselves, warns Leucci. “Our findings are based on studies in mice, so we don’t know how effective this treatment is in humans. Our study reports only one case in humans. 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/UZ Leuven), who is co-author of this study, we are exploring our options.”
This study was funded by, among others, Kom op tegen Kanker. “In the relatively short term, this research could lead to a new treatment option for patients with skin cancer,” said general manager Marc Michils. “Thanks to this data, a new clinical trial in patients can be initiated to investigate whether survival and quality of life improve. Thanks to our donors and campaigners, we were able to support Eleonora Leucci in this important step towards a new treatment against skin cancer.”