Project description:Our project is based on the hypothesis that ibrutinib could interfere with chronic lymphocytic leukemia (CLL) microenvironment, modulating the immune response. The aim of the project is to understand if and how ibrutinib modifies the tumor microenvironment accessory cells in CLL, specifically nurse like cells (NLC).
Project description:The Bruton tyrosine kinase (BTK) inhibitor ibrutinib has substantially improved therapeutic options for chronic lymphocytic leukemia (CLL). Although ibrutinib is not curative, it has a profound effect on CLL cells and may create new pharmacologically exploitable vulnerabilities. To identify such vulnerabilities, we developed a systematic approach that combines epigenome profiling (charting the gene-regulatory basis of cell state) with single-cell chemosensitivity profiling (quantifying cell-type-specific drug response) and bioinformatic data integration. By applying our method to a cohort of matched patient samples collected before and during ibrutinib therapy, we identified characteristic ibrutinib-induced changes that provide a starting point for the rational design of ibrutinib combination therapies. Specifically, we observed and validated preferential sensitivity to proteasome, PLK1, and mTOR inhibitors during ibrutinib treatment. More generally, our study establishes a broadly applicable method for investigating treatment-specific vulnerabilities by integrating the complementary perspectives of epigenetic cell states and phenotypic drug responses in primary patient samples.
Project description:Continuous treatment with ibrutinib not only exerts tumor control but also enhances T cell function in patients with chronic lymphocytic leukemia (CLL). We conducted longitudinal multiomics analyses in samples from CLL patients receiving ibrutinib upfront to identify potential adaptive mechanisms to Bruton Tyrosine Kinase (BTK) inhibition during the first 12 months of continuous therapy. Wefound that in T cells, ibrutinib reduced the expression of exhaustion markers, the proportion of Tregs and Tfh cells, as well as expression of genes related to activation, proliferation, differentiation, and metabolism. In CLL cells, we observed a downregulation of immunosuppression, adhesion, and migration mechanisms. Adaptation at molecular level, characterized by an increase in cancer cell fraction of CLL cells with mutated driver genes, was observed in around half of the patients. Interestingly, BTK C481S mutations were detected as early as after 6 months of treatment, particularly enriched in subsets of malignant cells retaining migrative capacity. These CLL cells with potential migrative capacity under ibrutinib also exhibited a distinct transcriptomic profile including upregulation of mTOR-AKT and Myc pathways. We identified high expression of TMBIM6 as a potential novel independent poor prognostic factor. Of note, BIA, a TMBIM6 antagonist, induced CLL cell apoptosis and synergized with ibrutinib. In summary, our comprehensive multi-omics analysis of CLL patients undergoing ibrutinib therapy has unveiled early immunomodulatory effects on T cells and adaptative mechanisms in CLL cells. These findings can contribute to the identification of resistance mechanisms and the discovery of novel therapeutic targets.
Project description:Ibrutinib, an irreversible Bruton Tyrosine Kinase (BTK) inhibitor, has revolutionized Chronic Lymphocytic Leukemia (CLL) treatment, but resistances to ibrutinib have emerged in relation or not to BTK mutations. Evolution patterns of CLL before and after ibrutinib therapy are often focused only on leukemic cells but must be investigated in the context of the CLL microenvironment. Single cell RNA-seq and related technologies allow a deeper characterization of cancer and normal cells. We therefore investigated whether ibrutinib treatment drives molecular changes in CLL. Here, we report the monitoring of a CLL patient under ibrutinib treatment using Cellular Indexing of Transcriptomes and Epitopes by sequencing (CITE-Seq) technology. We report that the short clinical relapse of this patient, driven by BTK mutation, is associated with intra-clonal heterogeneity and transcriptional and phenotypical modifications in both B leukemic and immune cells. These results open new therapeutic strategies for ibrutinib-refractory CLL patients.