Signaling pathways and bone marrow microenvironment in myelodysplastic neoplasms

Key signaling pathways within the Bone Marrow Microenvironment (BMM), such as Notch, Phosphoinositide-Specific Phospholipase C (PI-PLCs), Transforming Growth Factor β (TGF-β), and Nuclear Factor Kappa B (NF-κB), play a vital role in the progression of Myelodysplastic Neoplasms (MDS). Among the various BMM cell types, Mesenchymal Stromal Cells (MSCs) are particularly central to these pathways. While these signaling routes can independently affect both MSCs and Hematopoietic Stem Cells (HSCs), they most importantly alter the dynamics of their interactions, leading to abnormal changes in survival, differentiation, and quiescence. Notch and PI-PLC signaling facilitate intercellular communication, TGF-β promotes quiescence and suppresses hematopoiesis, and NF-κB-driven inflammatory responses foster an environment detrimental to normal hematopoiesis. This review highlights the role of these pathways within the MDS microenvironment, driving the development and progression of the disease and paving the way for new possible therapeutic strategies.