Crosstalk between TGF-β signaling and the microRNA machinery

The activin/transforming growth factor-beta (TGF-beta) pathway plays an important role in tumorigenesis either by its tumor suppressor or tumor promoting effect. Loss of members of the TGF-beta signaling by somatic mutations or epigenetic events, such as DNA methylation or regulation by microRNA (miRNA), may affect the signaling process. Most members of the TGF-beta pathway are known to be targeted by one or more miRNAs. In addition, the biogenesis of miRNAs is also regulated by TGF-beta both directly and through SMADs. Based on these interactions, it appears that autoregulatory feedback loops between TGF-beta and miRNAs influence the fate of tumor cells. Our aim is to review the crosstalk between TGF-beta signaling and the miRNA machinery to highlight potential novel therapeutic targets.