MicroRNAs in lymphoma, from diagnosis to targeted therapy

Purpose of reviewThe crucial role of microRNAs (miRNAs) in major biological processes and cancer development has been extensively described. Some stage-specific miRNAs are involved in B-cell differentiation, from the naive B-cell stage through germinal center maturation. Assuming that lymphoma cells are derived from B cells at different stages of maturation, miRNAs can be considered as both specific markers and putative target genes. Here, we review the most salient recent publications in this field, highlighting the clinical and therapeutic value of miRNAs in lymphomas.Recent findingsmiRNA array-based experiments have indicated that almost all mature lymphoid malignancies can be characterized by a distinct miRNA profile. Recent works have highlighted the crucial roles of miR-155 and miR-17-92 in the pathogeneses of diffuse large B-cell lymphoma and mantle cell lymphoma, respectively, indicating that they represent promising target genes. Novel mechanisms of miRNA deregulation have also been reported, including recurrent somatic mutations, MYC-driven miRNA repression, and cross-talk with other cells in the microenvironment.SummaryIn experimental models, some lymphomas are considered to be addicted to the sustained expression of targetable oncomiRs, such as miR-155 and miR-21. However, despite these results, which provide considerable information regarding lymphoma pathogenesis, the integration of miRNA analysis for lymphoma diagnosis or treatment in daily practice remains challenging.