Génétique humaine et Embryologie

Regulation of Mirna Pathway and Roles of Micrornas in Tumorigenesis and Metastasis

Abstract

Rong Jiang and Yujing Li

Although small non-coding RNAs, particularly microRNAs (miRNAs), small interference RNAs (siRNAs), and piwiinteracting RNAs (piRNAs), account for only a minor fraction of the expressed genome, they have been recognized as important regulators of gene and genome at post-transcriptional levels, functioning as RNA interference (RNAi) to regulate some of the most important biological processes in eukaryotic cells. Following the identification of the major components within the RNAi/miRNA pathway, some protein co-factors have been characterized to play significant roles in activity regulation of the RNAi/miRNA pathway in the last few years, suggesting that any regulators must be tightly regulated. It has been shown that microRNAs play vital roles in regulation of multiple signaling pathways and are involved in a variety of physiological and pathological processes. Given that high percentage of the identified human miRNAs-coding genes are located at tumor-related fragile chromosome regions, and that an increasing body of evidence supports the strong link between aberration of miRNA expression and malignancies, the regulatory network organizing the miRNAs, miRNA regulating factors and miRNA targets particularly the tumor suppressors or oncogenes is suggested. This review highlights the current evidence for the significance of the link of miRNAs and tumorigenesis and metastasis.