The roles of MicroRNA‑331 family in cancers

MicroRNAs (miRNAs) are single-stranded noncoding RNA strands that are involved in various pathological and physiological processes. Even though they do not code for any gene, they regulate gene expression by posttranscriptional modification through cleavage or translational repression of messenger RNA. Many miRNAs (for example, lethal-7 and miRNA-21) have been found to be involved in the pathogeneses of many diseases including cancers. The miRNA-331 family includes three miRNAs, namely, miRNA-331, miRNA-331-3p, and miRNA-331-5p. Recent studies have revealed that the miRNA-331 family is associated with the pathology of some cancers, including colorectal cancer, leukemia, hepatocellular carcinoma, prostate cancer, pancreatic cancer, breast cancer, melanoma, and lung cancer. Therefore, it is important to have a good understanding about how the miRNA-331 family regulates the pathogeneses of these cancers. In this review, we discuss the pathological and physiological roles of the miRNA-331 family. Understanding how these miRNAs regulate the gene expression levels of their targets and their involvement in cancers may lead to better therapeutic strategies to treat cancers.