Role of the Wnt/beta-catenin network in regulating hematopoiesis

The Wnt/beta-catenin pathway plays a significant role in several aspects of cell biology, including the stimulation of gene expression, growth, and mobility. Wnt proteins activate at least three cascades: Wnt/beta-catenin, Wnt/Ca(2+), and planar cell polarity. beta-Catenin is not only a very important element of many intracellular signaling pathways, including the Wnt pathway, but it also takes part in creating intercellular adhesive junctions. When overexpressed or mutated it functions as an oncogen. The Wnt/beta-catenin signaling pathway has been shown to play an important role in controlling the proliferation, survival, and differentiation of hematopoietic cells. Thus any aberrant signaling through this pathway may have a negative influence on hematopoiesis. Indeed, some recent findings suggest that Wnt/beta-catenin signaling is dysregulated in leukemias and lymphomas. All these data position the Wnt/beta-catenin signaling network as a critically important regulator of hematopoiesis and justify future efforts to better understand its role in the process of physiological and pathological hematopoiesis. The present review summarizes recent advances in this field.