MicroRNA control of epithelial-mesenchymal transition in cancer stem cells

Cancer stem cells (CSCs) represent a small subset of cancer cell populations that possess characteristics associated with normal stem cells. They have the ability to self-renew, and are able to generate diverse tumor cells and account for metastases. Therefore, CSCs are widely accepted as potential mediators of therapeutic resistance and novel targets for anti-cancer treatments. Recent progress has highlighted the significance of epithelial–mesenchymal transition (EMT) process in CSC formation, as well as the crucial role of microRNAs in controlling EMT and cancer metastasis. MicroRNAs are also reported to take part in the control of CSC functions and the regulation of cancer progression by affecting EMT process. Thus, it is highly crucial to develop deeper understanding of the mechanisms that how microRNAs control EMT processes and regulate CSC functions for better therapeutics of cancer disease. Herein we make this review to summarize the current understanding of the regulatory mechanisms of EMT in CSC initiation, with a special focus on the role of microRNAs in EMT control, and discuss the implications of targeting CSCs for cancer therapeutics.