Druggable Molecular Pathways in Chronic Lymphocytic Leukemia

Immunoglobulin light chain mutational status refines IGHV prognostic value in identifying chronic lymphocytic leukemia patients with early treatment requirement

The mutational status of immunoglobulin (IG) light chain genes in chronic lymphocytic leukemia (CLL) and its clinical impact have not been extensively studied. To assess their prognostic significance, the IG light chain gene repertoire in CLL patients has been evaluated using a training-validation approach. In the training cohort (N = 573 CLL), 92.5% showed productive IG light chain genes rearrangements, with IGKV4-1 (20.5%) and IGLV3-21 (19.0%) being the most common. A 99.0% somatic hypermutation cut-off was identified as the best predictor for time to first treatment (TTFT) in 414 Binet A CLL patients of the training cohort. Patients with unmutated (UM) light chain genes displayed a 10-year treatment free probability of 32.4% versus 73.2% for those with mutated (M) genes (p < 0.0001). Importantly, UM light chain genes maintained an independent association with a shorter TTFT when adjusted for the IPS-E prognostic model variables, that also includes IGHV mutational status. The validation cohort of 343 Rai 0 patients confirmed these findings, with UM light chain genes predicting a 7-year treatment free probability of 42.0% versus 73.7% for M genes (p < 0.0001). These results indicate that the mutational status of the light chain genes is an independent predictor of shorter TTFT in early-stage CLL patients.

Insights into genetic aberrations and signalling pathway interactions in chronic lymphocytic leukemia: from pathogenesis to treatment strategies

Chronic lymphocytic leukemia (CLL) is prevalent in adults and is characterized by the accumulation of mature B cells in the blood, bone marrow, lymph nodes, and spleens. Recent progress in therapy and the introduction of targeted treatments [inhibitors of Bruton's tyrosine kinase (BTKi) or inhibitor of anti-apoptotic B-cell lymphoma-2 (Bcl-2i) protein (venetoclax)] in place of chemoimmunotherapy have significantly improved the outcomes of patients with CLL. These advancements have shifted the importance of traditional predictive markers, leading to a greater focus on resistance genes and reducing the significance of mutations, such as TP53 and del(17p). Despite the significant progress in CLL treatment, some patients still experience disease relapse. This is due to the substantial heterogeneity of CLL as well as the interconnected genetic resistance mechanisms and pathway adaptive resistance mechanisms to targeted therapies in CLL. Although the knowledge of the pathomechanism of CLL has expanded significantly in recent years, the precise origins of CLL and the interplay between various genetic factors remain incompletely understood, necessitating further research. This review enhances the molecular understanding of CLL by describing how BCR signalling, NF-κB PI3K/AKT, and ROR1 pathways sustain CLL cell survival, proliferation, and resistance to apoptosis. It also presents genetic and pathway-adaptive resistance mechanisms in CLL. Identifying B-cell receptor (BCR) signalling as a pivotal driver of CLL progression, the findings advocate personalized treatment strategies based on molecular profiling, emphasizing the need for further research to unravel the complex interplay between BCR signalling and its associated pathways to improve patient outcomes.

Targeting the NTSR2/TrkB oncogenic pathway in chronic lymphocytic leukemia

Current therapies that target the B-cell receptor pathway or the inhibition of anti-apoptotic proteins do not prevent the progressive forms of chronic lymphocytic leukemia (CLL), have low long-term efficacy and are subject to therapeutic resistance. Deciphering the mechanisms of leukemic cell survival and searching for new specific targets therefore remain major challenges to improve the management of this disease. It was evidenced that NTSR2 (neurotensin receptor 2), through the recruitment of TRKB (tropomyosin related kinase B), induces survival pathways in leukemic B cells. We have investigated the therapeutic potential of this protein complex as a new target. The binding domain of NTSR2 and TRKB was identified and a peptide targeting the latter was designed. The peptide binds TRKB and efficiently decreases the interaction of the two proteins. It is also effectively internalized by CLL-B cells in which it notably affects Src family kinase signaling and anti-apoptotic proteins levels. It demonstrated a cytotoxic effect both in vitro on the MEC-1 cell line and ex vivo on a cohort of 30 CLL patients. Altogether, these results underline the therapeutic potential of the NTSR2/TRKB protein complex as a target in CLL and open new perspectives for the development of targeted therapies.

miR-142: A Master Regulator in Hematological Malignancies and Therapeutic Opportunities

MicroRNAs (miRNAs) are a type of non-coding RNA whose dysregulation is frequently associated with the onset and progression of human cancers. miR-142, an ultra-conserved miRNA with both active -3p and -5p mature strands and wide-ranging physiological targets, has been the subject of countless studies over the years. Due to its preferential expression in hematopoietic cells, miR-142 has been found to be associated with numerous types of lymphomas and leukemias. This review elucidates the multifaceted role of miR-142 in human physiology, its influence on hematopoiesis and hematopoietic cells, and its intriguing involvement in exosome-mediated miR-142 transport. Moreover, we offer a comprehensive exploration of the genetic and molecular landscape of the miR-142 genomic locus, highlighting its mutations and dysregulation within hematological malignancies. Finally, we discuss potential avenues for harnessing the therapeutic potential of miR-142 in the context of hematological malignancies.