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Here we evaluated the epigenomic and transcriptomic profile of XPO1 mutant chronic lymphocytic leukaemia (CLL) and their clinical phenotype. By ATAC-seq, chromatin regions that were more accessible in XPO1 mutated CLL were enriched of binding sites for transcription factors regulated by pathways emanating from the B-cell receptor (BCR), including NF-κB signalling, p38-JNK and RAS-RAF-MEK-ERK. XPO1 mutant CLL, consistent with the chromatin accessibility changes, were enriched with transcriptomic features associated with BCR and cytokine signalling. By combining epigenomic and transcriptomic data, MIR155HG, the host gene of miR-155, and MYB, the transcription factor that positively regulates MIR155HG, were upregulated by RNA-seq and their promoters were more accessible by ATAC-seq. To evaluate the clinical impact of XPO1 mutations, we investigated a total of 957 early-stage CLL subdivided into 3 independent cohorts (N = 276, N = 286 and N = 395). Next-generation sequencing analysis identified XPO1 mutations as a novel predictor of shorter time to first treatment (TTFT) in all cohorts. Notably, XPO1 mutations maintained their prognostic value independent of the immunoglobulin heavy chain variable status and early-stage prognostic models. These data suggest that XPO1 mutations, conceivably through increased miR-155 levels, may enhance BCR signalling leading to higher proliferation and shorter TTFT in early-stage CLL., (© 2023 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Chronic lymphocytic leukaemia (CLL) cells are strongly influenced by microenvironmental signals through the activation of distinct membrane receptors including the B-cell receptor and toll-like receptors (TLR). Recapitulating TLR stimulation in vitro by treating CLL cells with the TLR9 ligand CpG can induce metabolic activation and protection from apoptosis. We hypothesized that interfering with TLR signalling may be beneficial for treating CLL, and we tested in preclinical studies the effect of a specific interleukin-1 receptor-associated kinase 4 (IRAK4) inhibitory small molecule on primary leukaemic cells isolated from the peripheral blood of patients. We observed that IRAK4, an upstream kinase of the TLR pathway, is expressed in patients with CLL, and lower IRAK4 mRNA levels associate with a better outcome. The specific IRAK4 inhibitor disrupted TLR signalling as assessed by reduction of the specific biomarkers NFKBIZ and interleukin-6 mRNAs, and restrained the protective effect of in vitro TLR stimulation on cell viability. To note, IRAK4 inhibitor induced p53 and triggered apoptosis. Co-treatment of CLL cells with increasing concentrations of IRAK4i and the Bruton tyrosine kinase inhibitor ibrutinib demonstrated a synergistic effect. Our results suggest that targetting IRAK4 may represent a novel approach in CLL and may be combined with other signalling inhibitors., (© 2020 British Society for Haematology and John Wiley & Sons Ltd.)

The most effective strategy to prevent central nervous system (CNS) dissemination in diffuse large B-cell lymphoma (DLBCL) remains an important, unmet clinical need. Herein, we report a retrospective analysis of risk-tailored CNS prophylaxis in 200 human immunodeficiency virus-negative adults with DLBCL treated with rituximab-CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone) or similar. High risk of CNS relapse was defined by involvement of specific extranodal organs, or simultaneous presence of advanced stage and high serum lactate dehydrogenase level; CNS prophylaxis with high-dose methotrexate ± intrathecal chemotherapy (IT) was routinely used in high-risk patients diagnosed after 2007. CNS relapse risk was low in 93 patients and high in 107; 40 high-risk patients received prophylaxis, which consisted of IT alone in 7. At a median follow-up of 60 months, one low-risk and nine high-risk patients (1% vs. 8%; P = 0·01) experienced CNS relapse. In the high-risk group, CNS relapses occurred in 8/67 (12%) patients who did not receive prophylaxis and in 1/40 (2·5%) patients who did; the latter occurred in a patient managed with IT alone. CNS relapse rate was 12% (9/74) for patients treated with "inadequate" prophylaxis (none or IT only) and 0% (0/33) for patients managed with intravenous prophylaxis (P = 0·03). In conclusion, high-dose methotrexate-based prophylaxis significantly reduces CNS failures in high-risk patients stratified by involvement of specific extranodal sites and International Prognostic Index., (© 2014 John Wiley & Sons Ltd.)

'Multifocal bone lymphoma' or 'polyostotic lymphoma' is a neoplasm with exclusive multifocal involvement of the skeleton, without affecting lymph nodes or other soft tissues. Knowledge on this uncommon condition is limited because the related literature is sparse and fragmentary. We reviewed cases of multifocal bone diffuse large B-cell lymphoma (MB-DLBCL) registered in a clinico-pathological database of the International Extranodal Lymphoma Study Group that includes 499 cases of bone lymphoma. Clinical features, management and prognosis of 37 MB-DLBCL patients and 63 'controls' (stage-IV DLBCL and skeletal involvement) were analysed. Presentation and treatment of MB-DLBCL and controls were identical. At a median follow-up of 52 months (10-189), MB-DLBCL patients exhibited a significantly better response rate (92% vs. 65%; P = 0·002), progression-free survival (5-year: 56 ± 9% vs. 34 ± 6%; P = 0·003) and overall survival (5-year: 74 ± 8% vs. 36 ± 7%; P = 0·002). Among MB-DLBCL patients, the use of post-chemo radiotherapy was associated with better overall survival (5-year: 83 ± 12% vs. 55 ± 16%; P = 0·003). Two MB-DLBCL patients (5·4%) with spine and skull involvement experienced central nervous system (CNS) relapse. Thus, MB-DLBCL patients exhibit a significantly better prognosis compared to patients with advanced-stage DLBCL, and should be treated with conventional anthracycline-based chemotherapy, keeping intensified treatment for relapsing cases, considering involved-field radiotherapy, and CNS prophylaxis in high-risk patients., (© 2014 John Wiley & Sons Ltd.)