In experiments with mice, researchers from the Netherlands have found that some antibiotics may be effective in treating melanoma. The study was published in the Journal of Experimental Medicine.
Over time, some melanoma cells escape treatment by ‘turning off’ their proliferation systems and effectively hiding from the immune system to strike back at a later stage. To survive this inactive state, however, these cells rely on their mitochondria, the so-called ‘power plants’ of cells. As mitochondria are derived from bacteria that migrated into cells, they are vulnerable to certain antibiotics.
With this vulnerability in mind, the researchers thought to see if they could treat certain cancer cells with antibiotics. In experiments, they implanted patient-derived tumors into mice, and then treated them with antibiotics, either by themselves or in combination with pre-existing therapies for melanoma.
"The antibiotics quickly killed many cancer cells and could thus be used to buy the precious time needed for immunotherapy to kick in. In tumors that were no longer responding to targeted therapies, the antibiotics extended the lifespan of -- and in some cases even cured -- the mice," said Eleonora Leucci, one of the authors of the study.
The researchers used antibiotics that are rarely used to treat bacterial infections due to the rise of antibiotic resistance. They noted that cancer cells showed no resistance to these antibiotcs in their study, and thus may be repurposed for cancer.
The researchers also made note of a patient who used doxycycline to treat a bacterial infection. In addition to treating their infection, the researchers said that the antibiotics re-sensitized a resistant melanoma lesion to standard therapy in the patient.
"Our findings are based on research in mice, so we don't know how effective this treatment is in human beings,” says Leucci, “This result is cause for optimism, but we need more research and clinical studies to examine the use of antibiotics to treat cancer patients.”