Salinomycin is an antibacterial and coccidiostat

Coccidiostat

A coccidiostat is an antiprotozoal agent that acts upon Coccidia parasites.Examples include:* amprolium* arprinocid* artemether* clopidol* decoquinate* diclazuril* dinitolmide* ethopabate* halofuginone* lasalocid* monensin* narasin* nicarbazin...

 ionophore

Ionophore

An ionophore is a lipid-soluble molecule usually synthesized by microorganisms to transport ions across the lipid bilayer of the cell membrane...

 therapeutic drug.

Use in cancer

Salinomycin has been shown by Piyush Gupta et al. of the Massachusetts Institute of Technology

Massachusetts Institute of Technology

The Massachusetts Institute of Technology is a private research university located in Cambridge, Massachusetts. MIT has five schools and one college, containing a total of 32 academic departments, with a strong emphasis on scientific and technological education and research.Founded in 1861 in...

 and the Broad Institute

Broad Institute

The Broad Institute is a genomic medicine research center located in Cambridge, Massachusetts, United States. Although it is independently governed and supported as a 501 nonprofit research organization, the institute is formally affiliated with the Massachusetts Institute of Technology, Harvard...

 to kill breast cancer

Breast cancer

Breast cancer is cancer originating from breast tissue, most commonly from the inner lining of milk ducts or the lobules that supply the ducts with milk. Cancers originating from ducts are known as ductal carcinomas; those originating from lobules are known as lobular carcinomas...

 stem cells at least 100 times more effectively than another popular anti-cancer drug (paclitaxel

Paclitaxel

Paclitaxel is a mitotic inhibitor used in cancer chemotherapy. It was discovered in a U.S. National Cancer Institute program at the Research Triangle Institute in 1967 when Monroe E. Wall and Mansukh C. Wani isolated it from the bark of the Pacific yew tree, Taxus brevifolia and named it taxol...

) in mice. The study screened 16 000 different chemical compounds and found that only a small subset, including salinomycin and etoposide

Etoposide

Etoposide phosphate is an anti-cancer agent. It is known in the laboratory as a topoisomerase poison. Etoposide is often incorrectly referred to as a topoisomerase inhibitor in order to avoid using the term "poison" in a clinical setting...

, targeted cancer stem cells responsible for metastasis and relapse.
The mechanism of action by which Salinomycin kills cancer stem cells specifically remains unknown, but is thought to be due to its action as a potassium ionophore due to the detection of Nigericin

Nigericin

Nigericin is an antibiotic derived from Streptomyces hygroscopicus. Its isolation was described in the 1950s, and in 1968 the structure could be elucidated by X-ray crystallography. The structure and properties of nigericin are similar to the antibiotic monensin. Commercially it is obtained as a...

in the same compound screen. Salinomycin has high toxicity and a narrow therapeutic window which may limit its clinical use.