A medicinal chemistry perspective on salinomycin as a potent anticancer and anti-CSCs agent.

Tumors are phenotypically heterogeneous and include a small sub-population of cancer cells (2-5% of the tumor mass) with stem-cell like properties. The cancer stem cell hypothesis postulates that the cancer stem cells (CSCs) show the ability to seed the tumor to distant tissues/organs, and their presence results in cancer progression and relapses. Extensive efforts have therefore been directed at new therapy strategies to eliminate not only non-CSCs, but also cancer cells with stem-cell like properties. Importantly, in 2009, the natural ionophore - salinomycin (SAL) was shown to be promising in this respect; SAL selectively and efficiently reduced the proportion of breast CSCs in vitro and in vivo. Since this original report, SAL has been shown to be active against numerous cancer cells and CSCs of different origin, including those that display multi-drug resistance. This concise review article is focused on the possible role of SAL in future cancer therapy.