Abstract

Cancer stem cells (CSCs) are a subset of cells within a tumor having selfrenewal and differentiation capacity. Due to their “stem cell”-like properties, CSCs are thought to be responsible for cancer initiation, progression, metastasis, recurrence and drug resistance. Thus, therapeutic strategies that focus on targeting CSCs and their microenvironmental niche address the ineffectiveness of traditional cancer therapies to eradicate the CSCs that otherwise result in therapy resistance. Over the past years, a great effort has been invested in the development of new compounds and repositioning of already approved drugs that selectively target CSCs, some of which have been evaluated in preclinical and clinical studies.