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1.
Nature ; 612(7938): 148-155, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36424410

RESUMEN

Oncoproteins of the MYC family drive the development of numerous human tumours1. In unperturbed cells, MYC proteins bind to nearly all active promoters and control transcription by RNA polymerase II2,3. MYC proteins can also coordinate transcription with DNA replication4,5 and promote the repair of transcription-associated DNA damage6, but how they exert these mechanistically diverse functions is unknown. Here we show that MYC dissociates from many of its binding sites in active promoters and forms multimeric, often sphere-like structures in response to perturbation of transcription elongation, mRNA splicing or inhibition of the proteasome. Multimerization is accompanied by a global change in the MYC interactome towards proteins involved in transcription termination and RNA processing. MYC multimers accumulate on chromatin immediately adjacent to stalled replication forks and surround FANCD2, ATR and BRCA1 proteins, which are located at stalled forks7,8. MYC multimerization is triggered in a HUWE16 and ubiquitylation-dependent manner. At active promoters, MYC multimers block antisense transcription and stabilize FANCD2 association with chromatin. This limits DNA double strand break formation during S-phase, suggesting that the multimerization of MYC enables tumour cells to proliferate under stressful conditions.


Asunto(s)
ARN Polimerasas Dirigidas por ADN , Humanos , Cromatina/genética , ARN Polimerasas Dirigidas por ADN/metabolismo , Regiones Promotoras Genéticas/genética , ARN Polimerasa II/metabolismo , Transcripción Genética , Proteínas Supresoras de Tumor/metabolismo , Ubiquitina-Proteína Ligasas/metabolismo , Roturas del ADN de Doble Cadena , Fase S , Sitios de Unión , ARN Mensajero/biosíntesis
2.
Blood ; 143(8): 685-696, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-37976456

RESUMEN

ABSTRACT: CD19 chimeric antigen receptor (CAR) T cells and CD20 targeting T-cell-engaging bispecific antibodies (bispecs) have been approved in B-cell non-Hodgkin lymphoma lately, heralding a new clinical setting in which patients are treated with both approaches, sequentially. The aim of our study was to investigate the selective pressure of CD19- and CD20-directed therapy on the clonal architecture in lymphoma. Using a broad analytical pipeline on 28 longitudinally collected specimen from 7 patients, we identified truncating mutations in the gene encoding CD20 conferring antigen loss in 80% of patients relapsing from CD20 bispecs. Pronounced T-cell exhaustion was identified in cases with progressive disease and retained CD20 expression. We also confirmed CD19 loss after CAR T-cell therapy and reported the case of sequential CD19 and CD20 loss. We observed branching evolution with re-emergence of CD20+ subclones at later time points and spatial heterogeneity for CD20 expression in response to targeted therapy. Our results highlight immunotherapy as not only an evolutionary bottleneck selecting for antigen loss variants but also complex evolutionary pathways underlying disease progression from these novel therapies.


Asunto(s)
Linfoma de Células B , Linfoma , Humanos , Recurrencia Local de Neoplasia/metabolismo , Linfocitos T , Inmunoterapia Adoptiva/métodos , Linfoma de Células B/genética , Linfoma de Células B/terapia , Linfoma/metabolismo , Antígenos CD19 , Receptores de Antígenos de Linfocitos T
3.
Blood ; 2024 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-38701426

RESUMEN

Rearrangements that place the oncogenes MYC, BCL2, or BCL6 adjacent to superenhancers are common in mature B-cell lymphomas. Lymphomas with diffuse large B-cell lymphoma (DLBCL) or high-grade morphology with both MYC and BCL2 rearrangements are classified as high-grade B-cell lymphoma with MYC and BCL2 rearrangements ("double hit": HGBCL-DH-BCL2) and are associated with aggressive disease and poor outcomes. Although it is established that MYC rearrangements involving immunoglobulin (IG) loci are associated with inferior outcomes relative to those involving other non-IG superenhancers, the frequency of, and mechanisms driving, IG vs non-IG MYC rearrangements have not been elucidated. Here we used custom targeted capture and/or whole genome sequencing to characterize oncogene rearrangements across 883 mature B-cell lymphomas including Burkitt lymphoma, follicular lymphoma, DLBCL, and HGBCL-DH-BCL2 tumors. We demonstrate that, while BCL2 rearrangement topology is consistent across entities, HGBCL-DH-BCL2 have distinct MYC rearrangement architecture relative to tumors with single MYC rearrangements or with both MYC and BCL6 rearrangements (HGBCL-DH-BCL6), including both a higher frequency of non-IG rearrangements and different architecture of MYC::IGH rearrangements. The distinct MYC rearrangement patterns in HGBCL-DH-BCL2 occur on the background of high levels of somatic hypermutation across MYC partner loci in HGBCL-DH-BCL2, creating more opportunity to form these rearrangements. Furthermore, because one IGH allele is already disrupted by the existing BCL2 rearrangement, the MYC rearrangement architecture in HGBCL-DH-BCL2 likely reflects selective pressure to preserve both BCL2 and B cell receptor expression. These data provide new mechanistic explanations for the distinct patterns of MYC rearrangements observed across different lymphoma entities.

4.
Proc Natl Acad Sci U S A ; 120(10): e2219439120, 2023 03 07.
Artículo en Inglés | MEDLINE | ID: mdl-36853944

RESUMEN

Multiple myeloma (MM), a tumor of germinal center (GC)-experienced plasma cells, comprises distinct genetic subgroups, such as the t(11;14)/CCND1 and the t(4;14)/MMSET subtype. We have generated genetically defined, subgroup-specific MM models by the GC B cell-specific coactivation of mouse Ccnd1 or MMSET with a constitutively active Ikk2 mutant, mimicking the secondary NF-κB activation frequently seen in human MM. Ccnd1/Ikk2ca and MMSET/Ikk2ca mice developed a pronounced, clonally restricted plasma cell outgrowth with age, accompanied by serum M spikes, bone marrow insufficiency, and bone lesions. The transgenic plasma cells could be propagated in vivo and showed distinct transcriptional profiles, resembling their human MM counterparts. Thus, we show that targeting the expression of genes involved in MM subgroup-specific chromosomal translocations into mouse GC B cells translates into distinct MM-like diseases that recapitulate key features of the human tumors, opening the way to a better understanding of the pathogenesis and therapeutic vulnerabilities of different MM subgroups.


Asunto(s)
Mieloma Múltiple , Humanos , Animales , Ratones , Mieloma Múltiple/genética , Células Plasmáticas , Linfocitos B , Genes cdc , Animales Modificados Genéticamente , Modelos Animales de Enfermedad
5.
Lancet ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38971175

RESUMEN

BACKGROUND: Intensified systemic chemotherapy has the highest primary cure rate for advanced-stage, classical Hodgkin lymphoma but this comes with a cost of severe and potentially life long, persisting toxicities. With the new regimen of brentuximab vedotin, etoposide, cyclophosphamide, doxorubicin, dacarbazine, and dexamethasone (BrECADD), we aimed to improve the risk-to-benefit ratio of treatment of advanced-stage, classical Hodgkin lymphoma guided by PET after two cycles. METHODS: This randomised, multicentre, parallel, open-label, phase 3 trial was done in 233 trial sites across nine countries. Eligible patients were adults (aged ≤60 years) with newly diagnosed, advanced-stage, classical Hodgkin lymphoma (ie, Ann Arbor stage III/IV, stage II with B symptoms, and either one or both risk factors of large mediastinal mass and extranodal lesions). Patients were randomly assigned (1:1) to four or six cycles (21-day intervals) of escalated doses of etoposide (200 mg/m2 intravenously on days 1-3), doxorubicin (35 mg/m2 intravenously on day 1), and cyclophosphamide (1250 mg/m2 intravenously on day 1), and standard doses of bleomycin (10 mg/m2 intravenously on day 8), vincristine (1·4 mg/m2 intravenously on day 8), procarbazine (100 mg/m2 orally on days 1-7), and prednisone (40 mg/m2 orally on days 1-14; eBEACOPP) or BrECADD, guided by PET after two cycles. Patients and investigators were not masked to treatment assignment. Hierarchical coprimary objectives were to show (1) improved tolerability defined by treatment-related morbidity and (2) non-inferior efficacy defined by progression-free survival with an absolute non-inferiority margin of 6 percentage points of BrECADD compared with eBEACOPP. An additional test of superiority of progression-free survival was to be done if non-inferiority had been established. Analyses were done by intention to treat; the treatment-related morbidity assessment required documentation of at least one chemotherapy cycle. This trial was registered at ClinicalTrials.gov (NCT02661503). FINDINGS: Between July 22, 2016, and Aug 27, 2020, 1500 patients were enrolled, of whom 749 were randomly assigned to BrECADD and 751 to eBEACOPP. 1482 patients were included in the intention-to-treat analysis. The median age of patients was 31 years (IQR 24-42). 838 (56%) of 1482 patients were male and 644 (44%) were female. Most patients were White (1352 [91%] of 1482). Treatment-related morbidity was significantly lower with BrECADD (312 [42%] of 738 patients) than with eBEACOPP (430 [59%] of 732 patients; relative risk 0·72 [95% CI 0·65-0·80]; p<0·0001). At a median follow-up of 48 months, BrECADD improved progression-free survival with a hazard ratio of 0·66 (0·45-0·97; p=0·035); 4-year progression-free survival estimates were 94·3% (95% CI 92·6-96·1) for BrECADD and 90·9% (88·7-93·1) for eBEACOPP. 4-year overall survival rates were 98·6% (97·7-99·5) and 98·2% (97·2-99·3), respectively. INTERPRETATION: BrECADD guided by PET after two cycles is better tolerated and more effective than eBEACOPP in first-line treatment of adult patients with advanced-stage, classical Hodgkin lymphoma. FUNDING: Takeda Oncology.

6.
Br J Haematol ; 204(5): 1894-1898, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38279625

RESUMEN

Frequency, distribution and prognostic meaning of ALK-partner genes other than NPM1 in ALK-positive anaplastic large-cell lymphoma (ALCL) are unknown. Forty-nine of 316 ALCL diagnosed in the NHL-BFM study group showed no nuclear ALK expression suggestive of a variant ALK-partner; 41 were analysed by genomic capture high-throughput sequencing or specific RT-PCRs. NPM1::ALK was detected in 13 cases. Among the 28 patients with a non-NPM1::ALK-fusion partner, ATIC (n = 8; 29%) and TPM3 (n = 9; 32%) were the most common. Five of eight patients with ATIC::ALK-positive ALCL relapsed, none of nine with TPM3::ALK. Variant ALK-partners are rare and potentially associated with different prognoses.


Asunto(s)
Quinasa de Linfoma Anaplásico , Linfoma Anaplásico de Células Grandes , Nucleofosmina , Humanos , Linfoma Anaplásico de Células Grandes/genética , Linfoma Anaplásico de Células Grandes/patología , Niño , Masculino , Femenino , Quinasa de Linfoma Anaplásico/genética , Quinasa de Linfoma Anaplásico/análisis , Adolescente , Preescolar , Proteínas de Fusión Oncogénica/genética , Pronóstico , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Lactante , Tropomiosina
7.
Blood ; 140(11): 1278-1290, 2022 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-35639959

RESUMEN

Peripheral T-cell lymphomas (PTCLs) are heterogenous T-cell neoplasms often associated with epigenetic dysregulation. We investigated de novo DNA methyltransferase 3A (DNMT3A) mutations in common PTCL entities, including angioimmunoblastic T-cell lymphoma and novel molecular subtypes identified within PTCL-not otherwise specified (PTCL-NOS) designated as PTCL-GATA3 and PTCL-TBX21. DNMT3A-mutated PTCL-TBX21 cases showed inferior overall survival (OS), with DNMT3A-mutated residues skewed toward the methyltransferase domain and dimerization motif (S881-R887). Transcriptional profiling demonstrated significant enrichment of activated CD8+ T-cell cytotoxic gene signatures in the DNMT3A-mutant PTCL-TBX21 cases, which was further validated using immunohistochemistry. Genomewide methylation analysis of DNMT3A-mutant vs wild-type (WT) PTCL-TBX21 cases demonstrated hypomethylation in target genes regulating interferon-γ (IFN-γ), T-cell receptor signaling, and EOMES (eomesodermin), a master transcriptional regulator of cytotoxic effector cells. Similar findings were observed in a murine model of PTCL with Dnmt3a loss (in vivo) and further validated in vitro by ectopic expression of DNMT3A mutants (DNMT3A-R882, -Q886, and -V716, vs WT) in CD8+ T-cell line, resulting in T-cell activation and EOMES upregulation. Furthermore, stable, ectopic expression of the DNMT3A mutants in primary CD3+ T-cell cultures resulted in the preferential outgrowth of CD8+ T cells with DNMT3AR882H mutation. Single-cell RNA sequencing(RNA-seq) analysis of CD3+ T cells revealed differential CD8+ T-cell subset polarization, mirroring findings in DNMT3A-mutated PTCL-TBX21 and validating the cytotoxic and T-cell memory transcriptional programs associated with the DNMT3AR882H mutation. Our findings indicate that DNMT3A mutations define a cytotoxic subset in PTCL-TBX21 with prognostic significance and thus may further refine pathological heterogeneity in PTCL-NOS and suggest alternative treatment strategies for this subset.


Asunto(s)
Interferón gamma , Linfoma de Células T Periférico , Animales , Interferón gamma/genética , Linfoma de Células T Periférico/patología , Metiltransferasas/genética , Ratones , Mutación , Pronóstico , Receptores de Antígenos de Linfocitos T/genética
8.
Eur J Nucl Med Mol Imaging ; 51(5): 1383-1394, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38082196

RESUMEN

BACKGROUND: C-X-C motif chemokine receptor 4 (CXCR4) is overexpressed in various solid cancers and can be targeted by CXCR4-directed molecular imaging. We aimed to characterize the in-vivo CXCR4 expression in patients affected with solid tumors, along with a comparison to ex-vivo findings. METHODS: A total 142 patients with 23 different histologically proven solid tumors were imaged with CXCR4-directed PET/CT using [68 Ga]Ga-pentixafor (total number of scans, 152). A semi-quantitative analysis of the CXCR4-positive tumor burden including maximum standardized uptake values (SUVmax) and target-to-background ratios (TBR) using blood pool was conducted. In addition, we performed histopathological staining to determine the immuno-reactive score (IRS) from patients' tumor tissue and investigated possible correlations with SUVmax (by providing Spearman's rho ρ). Based on imaging, we also assessed the eligibility for CXCR4-targeted radioligand therapy or non-radioactive CXCR4 inhibitory treatment (defined as more than five CXCR4-avid target lesions [TL] with SUVmax above 10). RESULTS: One hundred three of 152 (67.8%) scans showed discernible uptake above blood pool (TBR > 1) in 462 lesions (52 primary tumors and 410 metastases). Median TBR was 4.4 (1.05-24.98), thereby indicating high image contrast. The highest SUVmax was observed in ovarian cancer, followed by small cell lung cancer, desmoplastic small round cell tumor, and adrenocortical carcinoma. When comparing radiotracer accumulation between primary tumors and metastases for the entire cohort, comparable SUVmax was recorded (P > 0.999), except for pulmonal findings (P = 0.013), indicative for uniform CXCR4 expression among TL. For higher IRS, a weak, but statistically significant correlation with increased SUVmax was observed (ρ = 0.328; P = 0.018). In 42/103 (40.8%) scans, more than five TL were recorded, with 12/42 (28.6%) exhibiting SUVmax above 10, suggesting eligibility for CXCR4-targeted treatment in this subcohort. CONCLUSIONS: In a whole-body tumor read-out, a substantial portion of prevalent solid tumors demonstrated increased and uniform [68 Ga]Ga-pentixafor uptake, along with high image contrast. We also observed a respective link between in- and ex-vivo CXCR4 expression, suggesting high specificity of the PET agent. Last, a fraction of patients with [68 Ga]Ga-pentixafor-positive tumor burden were rendered potentially suitable for CXCR4-directed therapy.


Asunto(s)
Complejos de Coordinación , Neoplasias , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Péptidos Cíclicos , Neoplasias/diagnóstico por imagen , Radioisótopos de Galio , Receptores CXCR4/metabolismo
9.
Br J Dermatol ; 2024 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-38924750

RESUMEN

BACKGROUND: Primary cutaneous acral CD8+ T-cell lymphoproliferative disorder (TLPD) is a rare and indolent lymphoma entity. Although known for years, the molecular pathogenesis is still unknown. OBJECTIVES: In order to better understand the molecular pathogenesis of cutaneous acral CD8+ TLPD and to identify further discriminatory markers to discern this lymphoma subtype from further CD8+ cutaneous lymphomas, we analysed five cases of cutaneous acral CD8+ TLPD for putative molecular alterations. METHODS: Somatic alterations were assessed by whole exome and targeted sequencing of paraffin-embedded tissue. Results were evaluated by immunohistochemical staining of respective relevant proteins. CD8+ cutaneous T-cell lymphomas (n = 12) served as control for KIR3DL1-staining. RESULTS: Copy number variations (CNV) analysis revealed a homozygous deletion of the KIR3DL1 gene in two of the analysed cases. This resulted in loss of KIR3DL1 protein expression which was observed in all cases of cutaneous acral CD8+ TLPD. In contrast, KIR3DL1 expression was more variable in other CD8+ cutaneous T-cell lymphomas with 50% of analysed cases (n = 12) being positive. In addition, one further case of acral CD8+ TLPD harboured a loss of function mutation in the PIK3R1 gene presumably activating the PI3K-AKT pathway. CONCLUSION: Alterations of KIR3DL1 gene may be of pathogenetic relevance for acral CD8+ TLPD. Loss of KIR3DL1 protein expression may support the diagnosis of this indolent lymphoma entity, albeit not being a subtype-specific discriminative feature.

10.
Nature ; 560(7718): 387-391, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29925955

RESUMEN

B cell receptor (BCR) signalling has emerged as a therapeutic target in B cell lymphomas, but inhibiting this pathway in diffuse large B cell lymphoma (DLBCL) has benefited only a subset of patients1. Gene expression profiling identified two major subtypes of DLBCL, known as germinal centre B cell-like and activated B cell-like (ABC)2,3, that show poor outcomes after immunochemotherapy in ABC. Autoantigens drive BCR-dependent activation of NF-κB in ABC DLBCL through a kinase signalling cascade of SYK, BTK and PKCß to promote the assembly of the CARD11-BCL10-MALT1 adaptor complex, which recruits and activates IκB kinase4-6. Genome sequencing revealed gain-of-function mutations that target the CD79A and CD79B BCR subunits and the Toll-like receptor signalling adaptor MYD885,7, with MYD88(L265P) being the most prevalent isoform. In a clinical trial, the BTK inhibitor ibrutinib produced responses in 37% of cases of ABC1. The most striking response rate (80%) was observed in tumours with both CD79B and MYD88(L265P) mutations, but how these mutations cooperate to promote dependence on BCR signalling remains unclear. Here we used genome-wide CRISPR-Cas9 screening and functional proteomics to determine the molecular basis of exceptional clinical responses to ibrutinib. We discovered a new mode of oncogenic BCR signalling in ibrutinib-responsive cell lines and biopsies, coordinated by a multiprotein supercomplex formed by MYD88, TLR9 and the BCR (hereafter termed the My-T-BCR supercomplex). The My-T-BCR supercomplex co-localizes with mTOR on endolysosomes, where it drives pro-survival NF-κB and mTOR signalling. Inhibitors of BCR and mTOR signalling cooperatively decreased the formation and function of the My-T-BCR supercomplex, providing mechanistic insight into their synergistic toxicity for My-T-BCR+ DLBCL cells. My-T-BCR supercomplexes characterized ibrutinib-responsive malignancies and distinguished ibrutinib responders from non-responders. Our data provide a framework for the rational design of oncogenic signalling inhibitors in molecularly defined subsets of DLBCL.


Asunto(s)
Carcinogénesis , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Complejos Multiproteicos/metabolismo , Transducción de Señal , Adenina/análogos & derivados , Animales , Biopsia , Sistemas CRISPR-Cas/genética , Carcinogénesis/genética , Diseño de Fármacos , Femenino , Humanos , Linfoma de Células B Grandes Difuso/genética , Ratones , Complejos Multiproteicos/química , Mutación , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , FN-kappa B/metabolismo , Piperidinas , Proteómica , Pirazoles/farmacología , Pirazoles/uso terapéutico , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Receptores de Antígenos de Linfocitos B/antagonistas & inhibidores , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/genética , Serina-Treonina Quinasas TOR/antagonistas & inhibidores , Serina-Treonina Quinasas TOR/metabolismo , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/metabolismo , Células Tumorales Cultivadas , Ensayos Antitumor por Modelo de Xenoinjerto
11.
PLoS Pathog ; 17(2): e1009210, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33596248

RESUMEN

Epstein-Barr virus (EBV) is best known for infection of B cells, in which it usually establishes an asymptomatic lifelong infection, but is also associated with the development of multiple B cell lymphomas. EBV also infects epithelial cells and is associated with all cases of undifferentiated nasopharyngeal carcinoma (NPC). EBV is etiologically linked with at least 8% of gastric cancer (EBVaGC) that comprises a genetically and epigenetically distinct subset of GC. Although we have a very good understanding of B cell entry and lymphomagenesis, the sequence of events leading to EBVaGC remains poorly understood. Recently, ephrin receptor A2 (EPHA2) was proposed as the epithelial cell receptor on human cancer cell lines. Although we confirm some of these results, we demonstrate that EBV does not infect healthy adult stem cell-derived gastric organoids. In matched pairs of normal and cancer-derived organoids from the same patient, EBV only reproducibly infected the cancer organoids. While there was no clear pattern of differential expression between normal and cancer organoids for EPHA2 at the RNA and protein level, the subcellular location of the protein differed markedly. Confocal microscopy showed EPHA2 localization at the cell-cell junctions in primary cells, but not in cancer cell lines. Furthermore, histologic analysis of patient tissue revealed the absence of EBV in healthy epithelium and presence of EBV in epithelial cells from inflamed tissue. These data suggest that the EPHA2 receptor is not accessible to EBV on healthy gastric epithelial cells with intact cell-cell contacts, but either this or another, yet to be identified receptor may become accessible following cellular changes induced by inflammation or transformation, rendering changes in the cellular architecture an essential prerequisite to EBV infection.


Asunto(s)
Células Epiteliales/virología , Infecciones por Virus de Epstein-Barr/virología , Herpesvirus Humano 4/fisiología , Organoides/virología , Receptor EphA2/metabolismo , Estómago/virología , Internalización del Virus , Células Epiteliales/metabolismo , Infecciones por Virus de Epstein-Barr/metabolismo , Humanos , Organoides/metabolismo , Estómago/fisiología , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/virología
12.
Blood ; 138(10): 871-884, 2021 09 09.
Artículo en Inglés | MEDLINE | ID: mdl-33876201

RESUMEN

Despite the development of novel targeted drugs, the molecular heterogeneity of diffuse large B-cell lymphoma (DLBCL) still poses a substantial therapeutic challenge. DLBCL can be classified into at least 2 major subtypes (germinal center B cell [GCB]-like and activated B cell [ABC]-like DLBCL), each characterized by specific gene expression profiles and mutation patterns. Here we demonstrate a broad antitumor effect of dimethyl fumarate (DMF) on both DLBCL subtypes, which is mediated by the induction of ferroptosis, a form of cell death driven by the peroxidation of phospholipids. As a result of the high expression of arachidonate 5-lipoxygenase in concert with low glutathione and glutathione peroxidase 4 levels, DMF induces lipid peroxidation and thus ferroptosis, particularly in GCB DLBCL. In ABC DLBCL cells, which are addicted to NF-κB and STAT3 survival signaling, DMF treatment efficiently inhibits the activity of the IKK complex and Janus kinases. Interestingly, the BCL-2-specific BH3 mimetic ABT-199 and an inhibitor of ferroptosis suppressor protein 1 synergize with DMF in inducing cell death in DLBCL. Collectively, our findings identify the clinically approved drug DMF as a promising novel therapeutic option in the treatment of both GCB and ABC DLBCLs.


Asunto(s)
Dimetilfumarato/farmacología , Ferroptosis/efectos de los fármacos , Linfoma de Células B Grandes Difuso/metabolismo , FN-kappa B/metabolismo , Proteínas de Neoplasias/metabolismo , Factor de Transcripción STAT3/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Peroxidación de Lípido/efectos de los fármacos , Peroxidación de Lípido/genética , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Ratones , FN-kappa B/genética , Proteínas de Neoplasias/genética , Factor de Transcripción STAT3/genética , Transducción de Señal/genética , Ensayos Antitumor por Modelo de Xenoinjerto , Pez Cebra
13.
Blood ; 137(20): 2785-2799, 2021 05 20.
Artículo en Inglés | MEDLINE | ID: mdl-33232972

RESUMEN

Aberrant B-cell receptor/NF-κB signaling is a hallmark feature of B-cell non-Hodgkin lymphomas, especially in diffuse large B-cell lymphoma (DLBCL). Recurrent mutations in this cascade, for example, in CD79B, CARD11, or NFKBIZ, and also in the Toll-like receptor pathway transducer MyD88, all deregulate NF-κB, but their differential impact on lymphoma development and biology remains to be determined. Here, we functionally investigate primary mouse lymphomas that formed in recipient mice of Eµ-myc transgenic hematopoietic stem cells stably transduced with naturally occurring NF-κB mutants. Although most mutants supported Myc-driven lymphoma formation through repressed apoptosis, CARD11- or MyD88-mutant lymphoma cells selectively presented with a macrophage-activating secretion profile, which, in turn, strongly enforced transforming growth factor ß (TGF-ß)-mediated senescence in the lymphoma cell compartment. However, MyD88- or CARD11-mutant Eµ-myc lymphomas exhibited high-level expression of the immune-checkpoint mediator programmed cell death ligand 1 (PD-L1), thus preventing their efficient clearance by adaptive host immunity. Conversely, these mutant-specific dependencies were therapeutically exploitable by anti-programmed cell death 1 checkpoint blockade, leading to direct T-cell-mediated lysis of predominantly but not exclusively senescent lymphoma cells. Importantly, mouse-based mutant MyD88- and CARD11-derived signatures marked DLBCL subgroups exhibiting mirroring phenotypes with respect to the triad of senescence induction, macrophage attraction, and evasion of cytotoxic T-cell immunity. Complementing genomic subclassification approaches, our functional, cross-species investigation unveils pathogenic principles and therapeutic vulnerabilities applicable to and testable in human DLBCL subsets that may inform future personalized treatment strategies.


Asunto(s)
Inmunidad Adaptativa , Proteínas Adaptadoras de Señalización CARD/genética , Senescencia Celular/fisiología , Guanilato Ciclasa/genética , Linfoma de Células B Grandes Difuso/inmunología , Factor 88 de Diferenciación Mieloide/genética , Proteínas de Neoplasias/genética , Linfocitos T Citotóxicos/inmunología , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Antígeno B7-H1/antagonistas & inhibidores , Antígenos CD79/genética , Línea Celular Tumoral , Quimiotaxis , Regulación Neoplásica de la Expresión Génica , Redes Reguladoras de Genes , Genes Reporteros , Genes myc , Humanos , Inhibidores de Puntos de Control Inmunológico , Linfoma de Células B Grandes Difuso/patología , Linfoma de Células B Grandes Difuso/terapia , Macrófagos/fisiología , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Mutación Missense , FN-kappa B/genética , FN-kappa B/metabolismo , Mutación Puntual , Proteína 2 Ligando de Muerte Celular Programada 1/antagonistas & inhibidores , ARN Neoplásico/biosíntesis , ARN Neoplásico/genética , Transcriptoma
14.
Blood ; 137(5): 646-660, 2021 02 04.
Artículo en Inglés | MEDLINE | ID: mdl-33538798

RESUMEN

Richter's transformation (RT) is an aggressive lymphoma that occurs upon progression from chronic lymphocytic leukemia (CLL). Transformation has been associated with genetic aberrations in the CLL phase involving TP53, CDKN2A, MYC, and NOTCH1; however, a significant proportion of RT cases lack CLL phase-associated events. Here, we report that high levels of AKT phosphorylation occur both in high-risk CLL patients harboring TP53 and NOTCH1 mutations as well as in patients with RT. Genetic overactivation of Akt in the murine Eµ-TCL1 CLL mouse model resulted in CLL transformation to RT with significantly reduced survival and an aggressive lymphoma phenotype. In the absence of recurrent mutations, we identified a profile of genomic aberrations intermediate between CLL and diffuse large B-cell lymphoma. Multiomics assessment by phosphoproteomic/proteomic and single-cell transcriptomic profiles of this Akt-induced murine RT revealed an S100 protein-defined subcluster of highly aggressive lymphoma cells that developed from CLL cells, through activation of Notch via Notch ligand expressed by T cells. Constitutively active Notch1 similarly induced RT of murine CLL. We identify Akt activation as an initiator of CLL transformation toward aggressive lymphoma by inducing Notch signaling between RT cells and microenvironmental T cells.


Asunto(s)
Leucemia Linfocítica Crónica de Células B/patología , Linfoma de Células B Grandes Difuso/patología , Proteínas de Neoplasias/fisiología , Proteínas Proto-Oncogénicas c-akt/fisiología , Receptor Notch1/fisiología , Animales , Evolución Clonal , Progresión de la Enfermedad , Activación Enzimática , Regulación Neoplásica de la Expresión Génica , Genes p53 , Leucemia Linfocítica Crónica de Células B/genética , Leucemia Linfocítica Crónica de Células B/fisiopatología , Linfocitos Infiltrantes de Tumor/inmunología , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/fisiopatología , Ratones , Ratones Endogámicos C57BL , Fenotipo , Fosfoproteínas/fisiología , Proteínas Proto-Oncogénicas c-akt/genética , Receptores de Antígenos de Linfocitos B/inmunología , Transducción de Señal/fisiología , Transcriptoma , Microambiente Tumoral , Proteína p53 Supresora de Tumor/fisiología , Regulación hacia Arriba
15.
Blood ; 137(19): 2646-2656, 2021 05 13.
Artículo en Inglés | MEDLINE | ID: mdl-33512419

RESUMEN

First-line therapy for younger patients with peripheral T-cell non-Hodgkin lymphoma (T-NHL) consists of 6 courses of cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) with or without etoposide (CHOEP), consolidated by high-dose therapy and autologous stem cell transplantation (auto-SCT). We hypothesized that allogeneic stem cell transplantation (allo-SCT) could improve outcomes. 104 patients with peripheral T-cell non-Hodgkin lymphoma, except ALK+ anaplastic large cell lymphoma, 18 to 60 years, all stages, and all age adjusted International Prognostic Index scores, except 0 and stage I, were randomized to 4 cycles of CHOEP and 1 cycle of dexamethasone, cytosine-arabinoside, and platinum (DHAP) followed by high-dose therapy and auto-SCT or myeloablative conditioning and allo-SCT. The primary end point was event-free survival (EFS) at 3 years. After a median follow-up of 42 months, the 3-year EFS after allo-SCT was 43%, as compared with 38% after auto-SCT. Overall survival at 3 years was 57% vs 70% after allo- or auto-SCT, without significant differences between treatment arms. None of the 21 responding patients proceeding to allo-SCT relapsed, as opposed to 13 of 36 patients (36%) proceeding to auto-SCT. Eight of 26 patients (31%) and none of 41 patients died of transplant-related toxicity after allo- and auto-SCT, respectively. The strong graft-versus-lymphoma effect after allo-SCT was counterbalanced by transplant-related mortality. This trial is registered at www.clinicaltrials.gov as #NCT00984412.


Asunto(s)
Linfoma de Células T Periférico/terapia , Trasplante de Células Madre de Sangre Periférica , Adulto , Aloinjertos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cisplatino/administración & dosificación , Terapia Combinada , Quimioterapia de Consolidación , Ciclofosfamida/administración & dosificación , Citarabina/administración & dosificación , Dexametasona/administración & dosificación , Doxorrubicina/administración & dosificación , Etopósido/administración & dosificación , Femenino , Enfermedad Injerto contra Huésped/etiología , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Agonistas Mieloablativos/uso terapéutico , Neoplasias Primarias Secundarias/etiología , Prednisolona/administración & dosificación , Estudios Prospectivos , Riesgo , Acondicionamiento Pretrasplante , Trasplante Autólogo , Vincristina/administración & dosificación
16.
Histopathology ; 82(7): 1105-1111, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36849712

RESUMEN

AIMS: Subclassification of large B cell lymphoma (LBCL) is challenging due to the overlap in histopathological, immunophenotypical and genetic data. In particular, the criteria to separate diffuse large B cell lymphoma (DLBCL) and high-grade B cell lymphoma (HGBL) are difficult to apply in practice. The Lunenburg Lymphoma Biomarker Consortium previously reported a cohort of over 5000 LBCL that included fluorescence in-situ hybridisation (FISH) data. This cohort contained 209 cases with MYC rearrangement that were available for a validation study by a panel of eight expert haematopathologists of how various histopathological features are used. METHODS AND RESULTS: Digital whole slide images of haematoxylin and eosin-stained sections allowed the pathologists to visually score cases independently as well as participate in virtual joint review conferences. Standardised consensus guidelines were formulated for scoring histopathological features and included overall architecture/growth pattern, presence or absence of a starry-sky pattern, cell size, nuclear pleomorphism, nucleolar prominence and a range of cytological characteristics. Despite the use of consensus guidelines, the results show a high degree of discordance among the eight expert pathologists. Approximately 50% of the cases lacked a majority score, and this discordance spanned all six histopathological features. Moreover, none of the histological variables aided in prediction of MYC single versus double/triple-hit or immunoglobulin-partner FISH-based designations or clinical outcome measures. CONCLUSIONS: Our findings indicate that there are no specific conventional morphological parameters that help to subclassify MYC-rearranged LBCL or select cases for FISH analysis, and that incorporation of FISH data is essential for accurate classification and prognostication.


Asunto(s)
Linfoma de Células B Grandes Difuso , Humanos , Reproducibilidad de los Resultados , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Biomarcadores , Proteínas Proto-Oncogénicas c-myc/genética , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-6/genética , Reordenamiento Génico
17.
Cancer Invest ; 41(2): 133-143, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36314889

RESUMEN

There is ample evidence today that vitamin D signalling via the vitamin D receptor (VDR) plays a pivotal role in cancer growth and metastasis. The aim of this study was to analyse VDR expression of primary breast cancer and corresponding bone metastases tissue samples. Collectively, 15 sample pairs and 11 samples of patients that did not develop metastases were analysed histologically for VDR expression (n = 41). Overall, VDR expression was significantly lower in bone metastases compared to primary tumour samples (p < .0001). Downregulation of the VDR in breast cancer cells may define a critical turning point in oncogenesis that accelerates cancer cell dissemination and metastases.


Asunto(s)
Neoplasias Óseas , Neoplasias de la Mama , Humanos , Femenino , Receptores de Calcitriol/genética , Receptores de Calcitriol/metabolismo , Neoplasias de la Mama/genética , Vitamina D , Neoplasias Óseas/genética , Neoplasias Óseas/secundario , Transducción de Señal
18.
Int J Mol Sci ; 24(14)2023 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-37511420

RESUMEN

Pulmonary fibrosis is a chronic and progressive disease with limited therapeutic options. Nitric oxide (NO) is suggested to reduce the progression of pulmonary fibrosis via NO-sensitive guanylyl cyclase (NO-GC). The exact effects of NO-GC during pulmonary fibrosis are still elusive. Here, we used a NO-GC knockout mouse (GCKO) and examined fibrosis and inflammation after bleomycin treatment. Compared to wildtype (WT), GCKO mice showed an increased fibrotic reaction, as myofibroblast occurrence (p = 0.0007), collagen content (p = 0.0006), and mortality (p = 0.0009) were significantly increased. After fibrosis induction, lymphocyte accumulations were observed in the lungs of GCKO but not in WT littermates. In addition, the total number of immune cells, specifically lymphocytes (p = <0.0001) and neutrophils (p = 0.0047), were significantly higher in the bronchoalveolar lavage fluid (BALF) of GCKO animals compared to WT, indicating an increased inflammatory response in the absence of NO-GC. The pronounced fibrotic response in GCKO mice was paralleled by significantly increased levels of transforming growth factor ß (TGFß) in BALF (p = 0.0207), which correlated with the total number of immune cells. Taken together, our data show the effect of NO-GC deletion in the pathology of lung fibrosis and the effect on immune cells in BALF. In summary, our results show that NO-GC has anti-inflammatory and anti-fibrotic properties in the murine lung, very likely by attenuating TGFß-mediated effects.


Asunto(s)
Fibrosis Pulmonar , Ratones , Animales , Guanilil Ciclasa Soluble/metabolismo , Fibrosis Pulmonar/tratamiento farmacológico , Fibrosis Pulmonar/patología , Pulmón/patología , Ratones Noqueados , Líquido del Lavado Bronquioalveolar , Factor de Crecimiento Transformador beta/metabolismo , Antiinflamatorios/uso terapéutico , Bleomicina/farmacología , Ratones Endogámicos C57BL
19.
Br J Haematol ; 199(3): 382-391, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-35880396

RESUMEN

Different studies have characterized the microenvironment and its prognostic impact in classic Hodgkin lymphoma whereas such analyses are pending for nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). We thus investigated characteristics of tumour cells and microenvironment in NLPHL and evaluated possible correlations with the clinical presentation. Lymph node samples from 152 NLPHL patients who had first-line treatment within the randomized German Hodgkin Study Group HD16-HD18 trials were available and analysed with regard to IgD status and nuclear size of the tumour cells as well as presence of PD1-positive follicular T helper cells and CD163-positive macrophages in the microenvironment. While large tumour cell nuclei and high numbers of PD1-positive follicular T helper cells in the microenvironment were more common in patients presenting with early/intermediate stages than in patients with advanced-stage disease (p < 0.0001, unpaired t-test; p = 0.0022, Mann-Whitney test), no differences between risk groups were observed in terms of the IgD status of the tumour cells and the content of CD163-positive macrophages in the microenvironment. PD1-positive follicular T helper cells were present in both cases with typical and variant growth patterns and rosetting around the tumour cells was observed in 96% of patients, indicating an important role of PD1-positive follicular T helper cells in NLPHL.


Asunto(s)
Enfermedad de Hodgkin , Humanos , Enfermedad de Hodgkin/patología , Linfocitos T Colaboradores-Inductores , Ganglios Linfáticos/patología , Pronóstico , Inmunoglobulina D , Microambiente Tumoral
20.
Br J Haematol ; 198(3): 482-491, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35362552

RESUMEN

The prognosis of patients with relapsed diffuse large B-cell lymphoma (DLBCL) remains poor with current options. Here we prospectively evaluated the combination of pixantrone with obinutuzumab for up to six cycles for patients with relapsed or refractory DLBCL. Overall response rate (ORR) was the primary end-point. Sixty-eight patients were evaluated, median age was 75 years, median number of prior lines was three (range 1-10), 52 patients (76.5%) were diagnosed with DLBCL and 16 (23.5%) patients had transformed indolent lymphoma or follicular lymphoma (FL) IIIB. ORR was 35.3% for all and 40% for evaluable patients (16.6% complete response), median progression-free survival (PFS) and overall survival (OS) were 2.8 months and 8 months, respectively. Analysis of the cell of origin revealed a superior course for patients with non-GCB (germinal centre B-cell-like) phenotype [median OS not reached (n.r.) vs 5.2 months]. Patients with one prior line had an improved outcome over patients treated in later lines (PFS n.r. vs 2.5 months). Disease progression was the main reason for premature termination. Adverse events were mainly haematologic. The combination treatment revealed no unexpected adverse events. Most relevant non-haematologic toxicity was infection in 28% of patients. In summary, pixantrone-obinutuzumab showed clinical activity with sometimes long-term remission; however, the trial failed to meet its primary end-point.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Linfoma de Células B Grandes Difuso , Recurrencia Local de Neoplasia , Anciano , Anticuerpos Monoclonales Humanizados/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Humanos , Isoquinolinas/uso terapéutico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/patología , Recurrencia Local de Neoplasia/tratamiento farmacológico , Estudios Prospectivos , Resultado del Tratamiento
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