Mitoribosome-targeting antibiotics may help in the treatment of melanoma, according to new findings.
The authors of the study, published online ahead of print in Journal of Experimental Medicine (July 21, 2021), write that these antibiotics exploit a vulnerability that arises in tumour cells when they try to survive other forms of cancer therapy.
“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,” said the paper's senior author Eleonora Leucci in a press release. “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 derive 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.”
Leucci is a cancer researcher and RNA biologist at KU Leuven in Leuven, Belgium.
To study the potential of antibiotics in this application, the researchers implanted patient-derived tumours into mice, which were then treated with antibiotics either as monotherapy or in combination with existing anti-melanoma therapies.
“The antibiotics quickly killed many cancer cells and could thus be used to buy the precious time needed for immunotherapy to kick in,” said Leucci. “In tumours that were no longer responding to targeted therapies, the antibiotics extended the lifespan of–and in some cases even cured–the mice.”
Antibiotics used in this trial were varieties that are rarely used for treating bacterial infection, due to rising antibiotic resistance, according to the release.
Leucci noted that antibiotic resistance does not impact the efficacy of the treatment in this study. “The cancer cells show high sensitivity to these antibiotics, so we can now look to repurpose them to treat cancer instead of bacterial infections.”
The authors note that more research will need to be done in human subjects.