Transcription factor and microRNA co-regulatory loops: Important regulatory motifs in biological processes and diseases

Abstract

Transcription factors (TFs) and microRNAs (miRNAs) can jointly regulate target gene expression in the forms of feed-forward loops (FFLs) or feedback loops (FBLs).These regulatory loops serve as important motifs in gene regulatory networks and play critical roles in multiple biological processes and different diseases. Major progress has been made in bioinformatics and experimental study for theTF andmiRNA co-regulation in recent years. To further speed up its identification and functional study, it is indispensable to make a comprehensive review. In this article, we summarize the types of FFLs and FBLs and their identifiedmethods. Then, we review the behaviors and functions for the experimentally identified loops according to biological processes and diseases. Future improvements and challenges are also discussed, which includesmore powerful bioinformatics approaches and high-throughput technologies inTF and miRNA target prediction, and the integration of networks of multiple levels.