By day, it’s known as a mild-mannered antibiotic. But secretly, enoxacin may also have the power to take down cancer, which had remained hidden until now. A study just published in PNAS found that enoxacin, which is normally used to treat urinary tract infections, also prevents the growth and metastasis of colorectal tumors in mice.
Researchers headed by Sonia Melo analyzed the effects of a group of molecules called fluoroquinolones on several different types of cancer cells. While the results wouldn’t exactly be considered the “super-powers” that we hinted at earlier, they were still pretty powerful. They discovered that:
- Enoxacin killed 7 different types of cancer cells, but had no effect on normal cells.
- Human colorectal tumor growth in mice slowed and did not metastasize to other organs after they were given injections of enoxacin.
Melo and her cohorts showed that enoxacin stops cancer cells in their tracks by inducing production of microRNAs, whose expression may have been altered by the tumor, through binding to a protein called TRBP, which processes miRNAs. Restarting miR production with enoxacin helps bring expression back to normal levels and makes it a good candidate for an anti-cancer therapeutic.
As senior author of the study, Manel Esteller at the Institute of Biomedical Research of Bellvitge (IDIBELL), commented, “Enoxacin binds to the protein that builds microRNAs and stimulates its activity ….our results, showing growth inhibition of tumor cells both in culture and animal models, should now be studied in patients”.
Because this drug is already being given to patients to treat bacterial infections and has very few side effects, there are fewer safety hurdles to clear before it hits the clinic, meaning it might not be long before it’s tested in patients with colorectal or other cancers. These findings also indicate that other fluoroquinolones or reagents that control microRNA production might be developed as therapeutics for patients with cancer.
Get the inside scoop on enoxacin’s secret powers at Proceedings of the National Academy of Sciences, February, 2011.