Kinome profiling of diffuse large B-cell lymphoma cells in response to dasatinib

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease, with at least one-third of its patients not responding to the current chemotherapy regimen, R-CHOP. By gene expression profiling, patients with DLBCL can be categorized into two clinically relevant subtypes: activated B-cell (ABC) DLBCL and germinal center B-cell (GCB). Patients with ABC DLBCL have a worse prognosis, and are defined by chronic, overactive signaling through the B-cell receptor and NF-κB pathways. We examined the effects of the Src family kinase (SFK) inhibitor dasatinib in a panel of ABC and GCB DLBCL cell lines, and found that the ABC DLBCL cell lines are much more sensitive to dasatinib than the GCB DLBCL cell lines. However, using multiplexed inhibitor bead coupled to mass spectrometry (MIB/MS) kinome profiling competition and western blot analysis, both subtypes display inhibition of the SFKs in response to dasatinib after both short- and long-term treatment. MIB/MS analyses revealed several cell cycle kinases, including CDK4, CDK6, and the Aurora kinases, are inhibited by dasatinib treatment in the ABC DLBCL subtype, but not in the GCB DLBCL subtype. The present findings have important implications for the clinical use of dasatinib for the treatment of ABC DLBCL, either alone or in combination with other agents.