miRNAs at the crossroad between hematopoietic malignancies and autoimmune pathogenesis.

The study of microRNA (miRNA) regulation in the pathogenesis of autoimmune diseases and hematopoietic malignancies provides new understanding of the mechanisms of disease and is currently the focus of many researchers in the field. Autoimmune disorders and cancers of immune system comprise a wide range of genetically complex diseases that share certain aspects of dysregulated genetic networks, most notably deactivation of apoptosis. miRNA mechanisms control gene expression at the post-transcriptional level, linking mRNA processing and gene function. Considerable amount of data have been accumulated that indicate that the alteration of miRNA expression closely mirrors the development of immune system diseases and is likely to play a role in their pathogenesis. However, a knowledge gap remains in our understanding of how miRNA dysregulation and the specific effects of miRNAs on target gene expression underlay the disease phenotype. Here we review a number of studies describing miRNA alterations in autoimmune diseases and hematopoietic cancers and discuss potential miRNA-regulated mechanisms that differentially influence the development of autoimmunity as compared to cancer progression.