Scientist inspired by 8-year-old daughter found positive effects of antibiotics in a successful breast cancer clinical trial.
In a breast cancer clinical trial, patients were orally administrated the antibiotic, Doxycycline, for 14 days before surgery and almost all saw a significant drop in cancer stem cells, the aggressive cells that drive tumour recurrence. This therefore suggests the positive effects of antibiotics on cancer patients.
The effects of antibiotics
The study gives hope for the efficacy of cheap, over-the-counter drugs being used alongside standard treatments to prevent cancer regrowth. Doxycycline is one of the most well-known and widely prescribed antibiotics, effective in treating pneumonia, sinusitis, chlamydia, syphilis, cholera and Lyme disease.
Professor Michael Lisanti, chair of translational medicine, University of Salford, UK, said: “We have very few FDA-approved drugs to target and reduce cancer stem cells, so to find that a drug that is effective, readily-available and costs just 10pence per patient per day and is highly significant, particularly as around two-thirds of cancer deaths occur due to recurrence after initial treatment.”
Lisanti himself has a remarkable story, whereby his 8-year-old daughter, Camilla, simply suggested to Lisanti why cancer could not be cured using antibiotics. From this he hypothesized that the repurposing of antibiotics could be a novel strategy for the treatment of cancer.
Details of the trial
In the breast cancer clinical trial, immuno-histochemical analysis was performed with known biomarkers of “stemness” (CD44), mitochondrial mass, cell proliferation, apoptosis and neo-angiogenesis. For each patient, the analysis was performed both on pre-operative specimens (core-biopsies) and surgical specimens.
Post-doxycycline tumour samples demonstrated a statistically significant decrease in CD44—between 17.65% and 66.67%, essentially showing the effects of antibiotics to be a positive one.
“What we infer here is that the stem cells selectively over-express key mitochondrial-related proteins, which means that if we can inhibit mitochondrial function we can disrupt the stem cells.” Explained professor Federica Sotgia, the University of Salford.
Because mitochondria evolved from bacteria, they explain, many classes of antibiotics including Doxycycline actually target mitochondria and inhibit the reproduction of stem cells. These latest observations, they say, are further evidence that mitochondria are both biomarkers and potential drug targets.
Lisanti added: “Our ability to treat cancer can only be enhanced by utilising drugs that are not only cheap but also widely available.”
“Since Doxycycline first became clinically available in 1967, its anti-cancer activity has been right under our nose, for more than 50 years.”