Tumor suppressive effects of mir‐124 and its function in neuronal development

Abstract

MicroRNA‐124 (miR‐124) is strongly expressed in neurons, and its expression increases as neurons mature. Through DNA methylation in the miR‐124 promoter region and adsorption of miR‐124 by non‐coding RNAs, miR‐124 expression is known to be reduced in many cancer cells, especially with high malignancy. Recently, numerous studies have focused on miR‐124 due to its promising tumor‐suppressive effects; however, the overview of their results is unclear. We surveyed the tumor‐suppressive effect of miR‐124 in glial cell lineage cancers, which are the most frequently reported cancer types involving miR‐124, and in lung, colon, liver, stomach, and breast cancers, which are the top five causes of cancer death. Reportedly, miR‐124 not only inhibits proliferation and accelerates apoptosis, but also comprehensively suppresses tumor malignant transformation. Moreover, we found that miR‐124 exerts its anti‐tumor effects by regulating a wide range of target genes, most notably STAT3 and EZH2. In addition, when compared to the original role of miR‐124 in neuronal development, we found that the miR‐124 target genes that contribute to neuronal maturation share similarities with genes that cause cancer cell metastasis and epithelial‐mesenchymal transition. We believe that the two apparently unrelated fields, cancer and neuronal development, can bring new discoveries to each other through the study of miR‐124.