Role of MiRNA in the Regulation of Blood Group Expression.

Background: MicroRNAs (miRNAs) are small, endogenous non-coding RNA molecules that inhibit gene expression through either destabilization of the target mRNA or translational repression. MiRNAs recognize target sites, most commonly found in the 3'-untranslated regions of cognate mRNAs. This review aims to provide a state-of-the-art overview of the role of miRNAs in the regulation of major blood group antigens such as ABH as well as cancer-specific glycans. Summary: Besides their known roles in the control of developmental processes, proliferation, apoptosis, and carcinogenesis, miRNAs have recently been identified to play a regulatory role during erythropoiesis and blood group antigen expression. Since only little is known about the function of the red cell membrane proteins carrying blood group antigens, it is of great interest to shed light on the regulatory mechanisms of blood group gene expression. Some carrier proteins of blood group antigens are not restricted to red blood cells and are widely expressed in other bodily fluids and tissues and quite a few play a crucial role in tumor cells, as either tumor suppressors or promoters. Key Message: All available data point at a tremendous physiological as well as pathophysiological relevance of miRNAs in context of blood group regulation. Furthermore, miRNAs are involved in the regulation of pleiotropic genetic pathways such as hematopoiesis and tumorigenesis and thus have to be studied in future research on this subject.