MicroRNAs: regulators of cancer metastasis and epithelial-mesenchymal transition (EMT)

Tumor metastasis is the main cause of death in patients with solid tumors.The epithelial-mesenchymal transition (EMT) process, in which epithelial cells are converted into mesenchymal cells, is frequently activated during cancer invasion and metastasis.MicroRNAs (miRNAs) are small, non-coding RNAs that provide widespread expressional control by repressing mRNA translation and inducing mRNA degradation.The fundamental roles of miRNAs in tumor growth and metastasis have been increasingly well recognized.A growing number of miRNAs are reported to regulate tumor invasion/metastasis through EMT-related and/ or non-EMT-related mechanisms.In this review, we discuss the functional role and molecular mechanism of miRNAs in regulating cancer metastasis and EMT.