Activation Of Nfat And Nfkb Transcription Factors Upon B Cell Receptor (Bcr) Stimulation Is Restricted To Evolutive Chronic Lymphocytic Leukemia (Cll) Cases.

Chronic lymphocytic leukemia (CLL) is a highly heterogeneous disease in which BCR signaling capacity plays a central role in disease progression. Previously, we have shown that BCR engagement allows the identification of two groups of patients with a strong correlation between the in vitro cell survival response and the biological criteria (IgVH somatic hypermutations, ZAP 70 expression ) or the clinical stage. One group, corresponding to non evolutive patients, showed absence of a substantial BCR signaling (Non responder). In contrast, BCR signaling promoted in vitro cell survival in the group of Responder cases corresponding to evolutive patients. In the latter only, response to BCR ligation was associated with induction of NFkB and NFAT regulated genes, such as Cyclin D2 and CD23.