[Dyserythropoiesis in myelodysplastic syndrome]

Myelodysplastic syndrome (MDS) is characterized by ineffective hematopoiesis including dyserythropoiesis. Recently, several signaling pathways have been implicated in dyserythropoiesis in MDS, such as the p53-S100A8/9-TLR4 pathway, which is involved in ineffective erythropoiesis in 5q- syndrome. Somatic mutations that target SF3B1, which encodes a component of the mRNA splicing machinery, have been identified in approximately 85% of patients with MDS presenting with ring sideroblasts (MDS-RS). SF3B1 mutations confer a change-of-function and cause aberrant splicing of genes that may be involved in the pathogenesis of MDS-RS. Recurrent mutations have also been identified in epigenetic regulator genes in MDS, including polycomb repressive complex 2 (PRC2) genes, and the loss of Ezh2, an enzymatic component of PRC2, enhances ineffective hematopoiesis and induces impaired erythropoiesis. A better understanding of the molecular mechanisms underlying dyserythropoiesis in MDS may lead to innovative novel therapeutic modalities.