MicroRNAs (miRNAs) are significant regulators of human hematopoietic stem cells (HSC), and their deregulation contributes to hematological malignancies. Myelodysplastic syndromes (MDS) represent a spectrum of hematological disorders characterized by dysfunctional HSC, ineffective blood cell production, progressive marrow failure, and an increased risk of developing acute myeloid leukemia (AML). Although miRNAs have been primarily studied in AML, only recently have similar studies been performed on MDS. In this review, we describe the normal function and expression of miRNAs in human HSC, and describe mounting evidence that deregulation of miRNAs contributes to the pathogenesis of MDS.

microRNA, Myelodysplastic syndrome, microarray, hematopoietic stem cells (HSC), acute myeloid leukemia (AML), epigenetic modifying drugs, chemotherapy, refractory anemia (RA), ringed sideroblasts (RARS), 5q- syndrome

Division of Experimental Hematology and Cancer Biology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH.