Micro RNAs in mouse models of lymphoid malignancies.

The discovery of microRNAs (miRNAs) has revealed a new layer of gene expression regulation that affects many normal and pathologic biological systems. Among the malignancies affected by the dysregulation of miRNAs, there are cancers of lymphoid origin in which miRNAs are thought to have tumor suppressive or tumor promoting activities, depending on the nature of their specific targets. In the last four to five years, the experimental field that provided the deepest insights into the in vivo biology of miRNAs is that of mouse modeling, in which transgenic and knockout animals mimic over-expression or down-regulation, respectively, of specific miRNAs involved in human leukemia/lymphoma. This review discusses recent advances in our understanding of lymphoid malignancies based on the natural and engineered mouse models of three different miRNAs: miR-15a/16-1 cluster, miR-155, and miR-17-92 cluster. [ABSTRACT FROM AUTHOR]