MicroRNA control of epithelial-mesenchymal transition and metastasis

Abstract

The great majority of cancer deaths are due to metastasis, which remains a poorly understood pathological process. The formation of a metastasis reflects a succession of complex steps leading to the macroscopic outgrowth of disseminated tumor cells at the secondary site. In the past 5 years, certain microRNAs (miRNAs) have been shown to regulate either a single step or multiple steps of metastasis, doing so by downregulating the expression of their target genes. In this review, we discuss recent studies on the functions and molecular mechanisms of miRNAs in regulating epithelial-mesenchymal transition (EMT) and cancer metastasis.

Fig. 1

Schematic diagram of miR-200’s regulation of EMT/MET and metastasis. The miR-200 family members target ZEB1/ZEB2 and Sec23a, and play opposing roles at early and late steps of metastasis

Fig. 2

miRNAs that regulate metastasis. Metastasis consists of multiple steps: epithelial–mesenchymal transition (EMT), local invasion, intravasation, extravasation, and colonization (as indicated by green boxes). miRNAs and their target genes are indicated in red/blue boxes and pink circles, respectively. Red box: metastasis-promoting miRNAs; blue box: metastasis-suppressing miRNAs