Alterations within the Osteo-Hematopoietic Niche in MDS and their Therapeutic Implications.

Hematopoietic and mesenchymal stem and progenitor cells are organized in the osteo-hematopoietic niche, a complex microenvironment ensuring self-renewal and differentiation. Perturbations of the niche architecture, the mutual cellular interactions and signaling pathways disrupt tissue homeostasis resulting in cytopenia and malignant diseases such as myelodysplastic syndromes (MDS), supporting the concept of niche-induced oncogenesis. Analyzing the available treatment options for patients harboring MDS, it becomes evident that many of them specifically modify components of the stem cell niche.

The role of microRNA in myelodysplastic syndromes: beyond DNA methylation and histone modification.

Myelodysplastic syndromes (MDS) are heterogeneous group of hematologic disorders of mostly elderly and based on distinct clinical phenotypes. Current paradigm of their pathogenesis relies on somatic gene mutations combined with the predisposing defective osteohematopoietic niche, but due to the breakout in epigenetic research scientific focus has steered toward two most common epigenetic modifications: methylation mechanisms and histone modification. At the same time, relatively few studies have been undertaken regarding the third epigenetic pathway - microRNAs - in MDS.