Profiling of biological and environmental risk factors in immunogenetic subgroups of chronic lymphocytic leukemia - Czech national study.

AIMS: This is a nation-wide survey of chronic lymphocytic leukemia (CLL) patients at six large hematology centers in the Czech Republic. The aim was to identify specific populations, social, and health characteristics of CLL subgroups divided according to the immunogenetic features of their B cell receptors (BCRs) and clonality. PATIENTS AND METHODS: Questionnaires directed to specific health, social, and environmental conditions were collected in a cohort of 573 CLL patients. For these patients, immunoglobulin heavy chain gene rearrangements were also analyzed in order to gain information about their clonality, IGHV mutational status, and the presence of stereotyped BCRs. Data extracted from the questionnaires were analyzed statistically in the context of immunogenetic features of the cohort. RESULTS: There were no statistically significant differences in the data collected in the survey between patients with mutated and patients with unmutated IGHV. However, patients with oligoclonal CLL reported health conditions such as hypercholesterolemia, hypertension, herpes simplex, tumors, and also, separately, CLL in 1st degree relatives, more often than their monoclonal counterparts. In patients with stereotyped BCRs, we found more frequent alcohol consumption and gastric infections in subset #1 cases and frequent cholecystectomies and familial CLL in subset #2 cases. CONCLUSION: To the best of our knowledge, this study is the first to investigate CLL immunogenetic features and clonality in the context of epidemiological data. We reported statistically significant associations suggesting the influence of certain health and social conditions on a number of clonal populations expanding in CLL and also on characteristic BCR features, especially stereotypy.

Casein kinase 1 is a therapeutic target in chronic lymphocytic leukemia.

Casein kinase 1δ/ε (CK1δ/ε) is a key component of noncanonical Wnt signaling pathways, which were shown previously to drive pathogenesis of chronic lymphocytic leukemia (CLL). In this study, we investigated thoroughly the effects of CK1δ/ε inhibition on the primary CLL cells and analyzed the therapeutic potential in vivo using 2 murine model systems based on the Eµ-TCL1-induced leukemia (syngeneic adoptive transfer model and spontaneous disease development), which resembles closely human CLL. We can demonstrate that the CK1δ/ε inhibitor PF-670462 significantly blocks microenvironmental interactions (chemotaxis, invasion and communication with stromal cells) in primary CLL cells in all major subtypes of CLL. In the mouse models, CK1 inhibition slows down accumulation of leukemic cells in the peripheral blood and spleen and prevents onset of anemia. As a consequence, PF-670462 treatment results in a significantly longer overall survival. Importantly, CK1 inhibition has synergistic effects to the B-cell receptor (BCR) inhibitors such as ibrutinib in vitro and significantly improves ibrutinib effects in vivo. Mice treated with a combination of PF-670462 and ibrutinib show the slowest progression of disease and survive significantly longer compared with ibrutinib-only treatment when the therapy is discontinued. In summary, this preclinical testing of CK1δ/ε inhibitor PF-670462 demonstrates that CK1 may serve as a novel therapeutic target in CLL, acting in synergy with BCR inhibitors. Our work provides evidence that targeting CK1 can represent an alternative or addition to the therapeutic strategies based on BCR signaling and antiapoptotic signaling (BCL-2) inhibition.