To investigate the three-dimensional (3D) genome architecture across normal B cell differentiation and in neoplastic cells from different subtypes of chronic lymphocytic leukemia and mantle cell ...lymphoma patients, here we integrate in situ Hi-C and nine additional omics layers. Beyond conventional active (A) and inactive (B) compartments, we uncover a highly-dynamic intermediate compartment enriched in poised and polycomb-repressed chromatin. During B cell development, 28% of the compartments change, mostly involving a widespread chromatin activation from naive to germinal center B cells and a reversal to the naive state upon further maturation into memory B cells. B cell neoplasms are characterized by both entity and subtype-specific alterations in 3D genome organization, including large chromatin blocks spanning key disease-specific genes. This study indicates that 3D genome interactions are extensively modulated during normal B cell differentiation and that the genome of B cell neoplasias acquires a tumor-specific 3D genome architecture.
We analyzed the utility of cell-free DNA (cfDNA) in a prospective population-based cohort to determine the mutational profile, assess tumor burden, and estimate its impact in response rate and ...outcome in patients with diffuse large B-cell lymphoma (DLBCL).
A total of 100 patients were diagnosed with DLBCL during the study period. Mutational status of 112 genes was studied in cfDNA by targeted next-generation sequencing. Paired formalin-fixed, paraffin-embedded samples and volumetric PET/CT were assessed when available.
Appropriate cfDNA to perform the analyses was obtained in 79 of 100 cases. At least one mutation could be detected in 69 of 79 cases (87%). The sensitivity of cfDNA to detect the mutations was 68% (95% confidence interval, 56.2-78.7). The mutational landscape found in cfDNA samples was highly consistent with that shown in the tissue and allowed genetic classification in 43% of the cases. A higher amount of circulating tumor DNA (ctDNA) significantly correlated with clinical parameters related to tumor burden (elevated lactate dehydrogenase and β2-microglobulin serum levels, advanced stage, and high-risk International Prognostic Index) and total metabolic tumor volume assessed by PET/CT. In patients treated with curative intent, high ctDNA levels (>2.5 log hGE/mL) were associated with lower complete response (65% vs. 96%;
< 0.004), shorter progression-free survival (65% vs. 85%;
= 0.038), and overall survival (73% vs. 100%;
= 0.007) at 2 years, although it did not maintain prognostic value in multivariate analyses.
In a population-based prospective DLBCL series, cfDNA resulted as an alternative source to estimate tumor burden and to determine the tumor mutational profile and genetic classification, which have prognostic implications and may contribute to a future tailored treatment.
Chronic lymphocytic leukaemia (CLL) is a frequent disease in which the genetic alterations determining the clinicobiological behaviour are not fully understood. Here we describe a comprehensive ...evaluation of the genomic landscape of 452 CLL cases and 54 patients with monoclonal B-lymphocytosis, a precursor disorder. We extend the number of CLL driver alterations, including changes in ZNF292, ZMYM3, ARID1A and PTPN11. We also identify novel recurrent mutations in non-coding regions, including the 3' region of NOTCH1, which cause aberrant splicing events, increase NOTCH1 activity and result in a more aggressive disease. In addition, mutations in an enhancer located on chromosome 9p13 result in reduced expression of the B-cell-specific transcription factor PAX5. The accumulative number of driver alterations (0 to ≥4) discriminated between patients with differences in clinical behaviour. This study provides an integrated portrait of the CLL genomic landscape, identifies new recurrent driver mutations of the disease, and suggests clinical interventions that may improve the management of this neoplasia.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
Mantle cell lymphoma (MCL) is a mature B-cell neoplasm with a heterogeneous clinical and biological behavior. SOX11 oncogenic expression contributes to the aggressiveness of these tumors by different ...mechanisms, including tumor and stromal cell interactions. However, the precise composition of the immune cell microenvironment of MCL, its possible relationship to SOX11 expression, and how it may contribute to tumor behavior is not well known. Here, we performed an integrative transcriptome analysis of 730 immune-related genes combined with the immune cell phenotype analysis by immunohistochemistry in SOX11+ and SOX11− primary nodal MCL cases and non-neoplastic reactive lymph nodes. SOX11+ MCL had a significant lower T-cell intratumoral infiltration compared with negative cases. A reduced expression of MHCI/II-like and T-cell costimulation and signaling activation related transcripts was significantly associated with poor clinical outcome. Moreover, we identified CD70 as a SOX11 direct target gene, whose overexpression was induced in SOX11+, but not SOX11− tumor cells by CD40L in vitro. CD70 was overexpressed in primary SOX11+ MCL and it was associated with an immune unbalance of the tumor microenvironment characterized by increased number of effector regulatory t (Treg) cell infiltration, higher proliferation, and aggressive clinical course. CD27 was expressed with moderate to strong intensity in 76% of cases. Overall, our results suggest that SOX11 expression in MCL is associated with an immunosuppressive microenvironment characterized by CD70 overexpression in tumor cells, increased Treg cell infiltration and downmodulation of antigen processing, and presentation and T-cell activation that could promote MCL progression and represent a potential target for tailored therapies.
•SOX11+ MCL has a tumor microenvironment with reduced number of immune cells and down-modulation of genes involved in antitumor response.•CD70 is overexpressed in SOX11+ MCL associated with increased Treg infiltration, high proliferation, and aggressive clinical course.
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Mantle cell lymphoma (MCL) is an incurable B-cell neoplasm characterized by an aggressive behavior, short responses to conventional therapies and SOX11 overexpression, which is associated with ...aggressive disease features and inferior clinical outcome of patients. Oxidative stress is known to induce tumorigenesis and tumor progression, whereas high expression levels of antioxidant genes have been associated with chemoresistance in different cancers. However, the role of oxidative stress in MCL pathogenesis and the involvement of SOX11 regulating redox homeostasis in MCL cells are largely unknown. Here, by integrating gene set enrichment analysis of two independent series of MCL, we observed that SOX11+ MCL had higher reactive oxygen species (ROS) levels compared to SOX11- MCL primary tumors and increased expression of Peredoxine2 (PRDX2), which upregulation significantly correlated with SOX11 overexpression, higher ROS production and worse overall survival of patients. SOX11 knockout (SOX11KO) significantly reduced PRDX2 expression, and SOX11KO and PRDX2 knockdown (PRDX2KD) had increased ROS levels and ROS-mediated tumor cell death upon treatment with drugs, compared to control MCL cell lines. Our results suggest an aberrant redox homeostasis associated with chemoresistance in aggressive MCL through SOX11-mediated PRDX2 upregulation, highlighting PRDX2 as promising target for new therapeutic strategies to overcome chemoresistance in aggressive MCLs.
Summary
Anaplastic large cell lymphoma (ALCL) is a T/null‐cell neoplasm characterized by chromosomal translocations involving the anaplastic lymphoma kinase (ALK) gene (ALK). Tumours with similar ...morphology and phenotype but negative for ALK have been also recognized. The secondary chromosomal imbalances of these lymphomas are not well known. We have examined 74 ALCL, 43 ALK‐positive and 31 ALK‐negative, cases by comparative genomic hybridization (CGH), and locus‐specific alterations for TP53 and ATM were examined by fluorescence in situ hybridization and real‐time quantitative polymerase chain reaction. Chromosomal imbalances were detected in 25 (58%) ALK‐positive and 20 (65%) ALK‐negative ALCL. ALK‐positive ALCL with NPM‐ALK or other ALK variant translocations showed a similar profile of secondary genetic alterations. Gains of 17p and 17q24‐qter and losses of 4q13‐q21, and 11q14 were associated with ALK‐positive cases (P = 0·05), whereas gains of 1q and 6p21 were more frequent in ALK‐negative tumours (P = 0·03). Gains of chromosome 7 and 6q and 13q losses were seen in both types of tumours. ALCL‐negative tumours had a significantly worse prognosis than ALK‐positive. However no specific chromosomal alterations were associated with survival. In conclusion, ALK‐positive and negative ALCL have different secondary genomic aberrations, suggesting they correspond to different genetic entities.
To study the main clinicobiologic features, response, and outcome of patients with diffuse large B-cell lymphoma (DLBCL) according to the primary site, lymph node, or different extranodal organs of ...the disease.
We included 382 patients consecutively diagnosed with DLBCL in a single institution during a 13-year period. Morphology, immunophenotyping, proliferation index, differentiation profile, bcl-2/JH rearrangement, and clinical characteristics were analyzed according to the primary site of the lymphoma.
Sites of the disease were: lymph node, 222 cases (58%); Waldeyer's ring (WR), 42 (11%); and extranodal sites, 118 (31%), including GI tract in 45 cases. Primary extranodal cases, particularly GI, showed a bcl-6 expression more frequently than nodal cases. Patients with primary WR or GI lymphomas presented with early-stage disease, no marrow infiltration, normal serum lactate dehydrogenase, and low- to low/intermediate-risk international prognostic index (IPI) more frequently than the remainder. Complete response (CR) rate was 63%, with WR and GI lymphomas having a higher CR rate (85% and 80%, respectively) than the other groups. In the whole series, 5-year overall survival (OS) was 52%. Patients with WR or GI lymphomas showed better OS (5-year OS: 77% and 68%, respectively) than patients with nodal or other extranodal sites. In the multivariate analysis, IPI, bulky disease, and beta2-microglobulin were the main variables to predict OS; no nodal or extranodal site maintained their prognostic value.
In the present series, the primary site of disease was associated with particular clinicopathologic features and outcome, though the latter largely depended on other factors.
SOX11 overexpression has been associated with aggressive behavior of mantle cell lymphomas (MCL). SOX11 is overexpressed in embryonic and cancer stem cells (CSC) of some tumors. Although CSC have ...been isolated from primary MCL, their relationship to SOX11 expression and contribution to MCL pathogenesis and clinical evolution remain unknown. Here, we observed enrichment in leukemic and hematopoietic stem cells gene signatures in SOX11+ compared to SOX11- MCL primary cases. Musashi-2 (MSI2) emerged as one of the most significant upregulated stem cell-related genes in SOX11+ MCLs. SOX11 is directly bound to the MSI2 promoter upregulating its expression in vitro. MSI2 intronic enhancers were strongly activated in SOX11+ MCL cell lines and primary cases. MSI2 upregulation was significantly associated with poor overall survival independently of other high-risk features of MCL. MSI2 knockdown decreased the expression of genes related to apoptosis and stem cell features and significantly reduced clonogenic growth, tumor cell survival and chemoresistance in MCL cells. MSI2-knockdown cells had reduced tumorigenic engraftment into mice bone marrow and spleen compared to control cells in xenotransplanted mouse models. Our results suggest that MSI2 might play a key role in sustaining stemness and tumor cell survival, representing a possible novel target for therapeutic interventions in MCL.
Follicular lymphoma (FL), the most common indolent non-Hodgkin lymphoma, constitutes a paradigm of immune tumor microenvironment (TME) contribution to disease onset, progression, and heterogenous ...clinical outcome. Here we present the first FL-Patient Derived Lymphoma Spheroid (FL-PDLS), including fundamental immune actors and features of TME in FL lymph nodes (LNs). FL-PDLS is organized in disc-shaped 3D structures composed of proliferating B and T cells, together with macrophages with an intermediate M1/M2 phenotype. FL-PDLS recapitulates the most relevant B-cell transcriptional pathways present in FL-LN (proliferation, epigenetic regulation, mTOR, adaptive immune system, among others). The T cell compartment in the FL-PDLS preserves CD4 subsets (follicular helper, regulatory, and follicular regulatory), also encompassing the spectrum of activation/exhaustion phenotypes in CD4 and CD8 populations. Moreover, this system is suitable for chemo and immunotherapy testing, recapitulating results obtained in the clinic. FL-PDLS allowed uncovering that soluble galectin-9 limits rituximab, rituximab, plus nivolumab/TIM-3 antitumoral activities. Blocking galectin-9 improves rituximab efficacy, highlighting galectin-9 as a novel immunotherapeutic target in FL. In conclusion, FL-PDLS maintains the crosstalk between malignant B cells and the immune LN-TME and constitutes a robust and multiplexed pre-clinical tool to perform drug screening in a patient-derived system, advancing toward personalized therapeutic approaches.
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