Notch and Wnt signaling in T-lymphocyte development and acute lymphoblastic leukemia.

Many acute lymphoblastic leukemias can be considered as malignant counterparts of cells in the various stages of normal lymphoid development in bone marrow and thymus. T-cell development in the thymus is an ordered and tightly controlled process. Two evolutionary conserved signaling pathways, which were first discovered in Drosophila, control the earliest steps of T-cell development. These are the Notch and Wnt-signaling routes, which both are deregulated in several types of leukemias. In this review we discuss both pathways, with respect to their signaling mechanisms, functions during T-cell development and their roles in development of leukemias, especially T-cell acute lymphoblastic leukemia.