Essential functions of miR‐125b in cancer

MicroRNAs (miRNAs) are small and highly conserved non‐coding RNAs that silence target mRNAs, and compelling evidence suggests that they play an essential role in the pathogenesis of human diseases, especially cancer. miR‐125b, which is the mammalian orthologue of the first discovered miRNA lin‐4 in Caenorhabditis elegans, is one of the most important miRNAs that regulate various physiological and pathological processes. The role of miR‐125b in many types of cancer has been well established, and so here we review the current knowledge of how miR‐125b is deregulated in different types of cancer; its oncogenic and/or tumour‐suppressive roles in tumourigenesis and cancer progression; and its regulation with regard to treatment response, all of which are underlined in multiple studies. The emerging information that elucidates the essential functions of miR‐125b might help support its potentiality as a diagnostic and prognostic biomarker as well as an effective therapeutic tool against cancer.