TY - JOUR A1 - Murti, Krisna A1 - Fender, Hendrik A1 - Glatzle, Carolin A1 - Wismer, Rhoda A1 - Sampere-Birlanga, Salvador A1 - Wild, Vanessa A1 - Muhammad, Khalid A1 - Rosenwald, Andreas A1 - Serfling, Edgar A1 - Avots, Andris T1 - Calcineurin-independent NFATc1 signaling is essential for survival of Burkitt lymphoma cells JF - Frontiers in Oncology N2 - In Burkitt lymphoma (BL), a tumor of germinal center B cells, the pro-apoptotic properties of MYC are controlled by tonic B cell receptor (BCR) signals. Since BL cells do not exhibit constitutive NF-κB activity, we hypothesized that anti-apoptotic NFATc1 proteins provide a major transcriptional survival signal in BL. Here we show that post-transcriptional mechanisms are responsible for the calcineurin (CN) independent constitutive nuclear over-expression of NFATc1 in BL and Eµ-MYC – induced B cell lymphomas (BCL). Conditional inactivation of the Nfatc1 gene in B cells of Eµ-MYC mice leads to apoptosis of BCL cells in vivo and ex vivo. Inhibition of BCR/SYK/BTK/PI3K signals in BL cells results in cytosolic re-location of NFATc1 and apoptosis. Therefore, NFATc1 activity is an integrated part of tonic BCR signaling and an alternative target for therapeutic intervention in BL. KW - apoptosis KW - Burkitt lymphoma KW - cyclosporin A KW - nuclear localization KW - NFATc1 KW - activated B cell-like diffuse large B-cell lymphoma (ABC-DLBCL) KW - B cell receptor (BCR) KW - Burkitt lymphoma (BL) Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-323103 VL - 13 ER -