The calcineurin/NFAT signaling pathway - A novel therapeutic target in leukemia and solid tumors

The calcineurin/NFAT signaling pathway is unique to vertebrates and clear genetic evidences show that it plays critical roles in orchestrating the intricate cellular interactions that characterize vertebrate development and morphogenesis. In this setting, the transcriptional regulators of the NFAT family function as molecular integrators of specific calcium signals with other signaling pathways, including MAPkinase, WNT or NOTCH. Deregulation of calcineurin/NFAT signaling and/ or abnormal expression of its components have recently been reported in solid tumors of epithelial origin, lymphoma and lymphoid leukemia. Our studies in mouse models of human T-ALL/ lymphoma shows that persistent activation of calcineurin/ NFAT signaling is pro-oncogenic in vivo and can be efficiently targeted by well-characterized calcineurin inhibitors. We further discuss facts and hypotheses concerning the molecular events that may act upstream and downstream of calcineurin and/ or NFAT activation in different type of cancer cells.