Cancer stem cells and tumor metastasis.

Cancer stem cells (CSCs) are endowed with an inherent resistance to cytotoxic drugs, and are closely related to the migration, invasiveness, and anti-apoptotic ability of the cancer cells. Epithelial-mesenchymal transition (EMT) is a process where epithelial cells acquire the highly invasive and metastatic characteristics of mesenchymal cells, and has a close connection with CSCs. In this paper, the authors address the recent progress made in the relationship between the EMT status of CSCs and tumor metastasis and between the localization and chemotaxis of CSCs and the formation of the metastatic colonies, as well as the relation of CSCs with the therapeutic strategy for cancer treatment.