microRNAs in cancer management

Since the identification of microRNAs (miRNAs) in 1993, and the subsequent discovery of their highly conserved nature in 2000, the amount of research into their function-particularly how they contribute to malignancy-has greatly increased. This class of small RNA molecules control gene expression and provide a previously unknown control mechanism for protein synthesis. As such, it is unsurprising that miRNAs are now known to play an essential part in malignancy, functioning as tumour suppressors and oncogenes. This Review summarises the present understanding of how miRNAs operate at the molecular level; how their dysregulation is a crucial part of tumour formation, maintenance, and metastasis; how they can be used as biomarkers for disease type and grade; and how miRNA-based treatments could be used for diverse types of malignancies.