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1.
Leukemia ; 35(1): 169-176, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32203141

RESUMO

Richter transformation (RT) is defined as development of aggressive lymphoma in patients (pts) with CLL. The incidence rates of RT among pts with CLL range from 2 to 10%. The aim of this analysis is to report the frequency, characteristics and outcomes of pts with RT enrolled in trials of the GCLLSG. A total of 2975 pts with advanced CLL were reviewed for incidence of RT. Clinical, laboratory, and genetic data were pooled. Time-to-event data, starting from time of CLL diagnosis, of first-line therapy or of RT diagnosis, were analyzed by Kaplan-Meier methodology. One hundred and three pts developed RT (3%): 95 pts diffuse large B-cell lymphoma (92%) and eight pts Hodgkin lymphoma (8%). Median observation time was 53 months (interquartile range 38.1-69.5). Median OS from initial CLL diagnosis for pts without RT was 167 months vs 71 months for pts with RT (HR 2.64, CI 2.09-3.33). Median OS after diagnosis of RT was 9 months. Forty-seven pts (46%) received CHOP-like regimens for RT treatment. Three pts subsequently underwent allogeneic and two pts autologous stem cell transplantation. Our findings show that within a large cohort of GCLLSG trial participants, 3% of the pts developed RT after receiving first-line chemo- or chemoimmunotherapy. This dataset confirms the ongoing poor prognosis and high mortality associated with RT.


Assuntos
Transformação Celular Neoplásica , Leucemia Linfocítica Crônica de Células B/patologia , Linfoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Transformação Celular Neoplásica/genética , Progressão da Doença , Feminino , Variação Genética , Alemanha , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/terapia , Linfoma/etiologia , Linfoma/mortalidade , Linfoma/terapia , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Análise de Sobrevida , Fatores de Tempo , Adulto Jovem
2.
Blood ; 136(24): 2786-2802, 2020 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-33301031

RESUMO

T-cell prolymphocytic leukemia (T-PLL) is a poor-prognostic neoplasm. Differentiation stage and immune-effector functions of the underlying tumor cell are insufficiently characterized. Constitutive activation of the T-cell leukemia 1A (TCL1A) oncogene distinguishes the (pre)leukemic cell from regular postthymic T cells. We assessed activation-response patterns of the T-PLL lymphocyte and interrogated the modulatory impact by TCL1A. Immunophenotypic and gene expression profiles revealed a unique spectrum of memory-type differentiation of T-PLL with predominant central-memory stages and frequent noncanonical patterns. Virtually all T-PLL expressed a T-cell receptor (TCR) and/or CD28-coreceptor without overrepresentation of specific TCR clonotypes. The highly activated leukemic cells also revealed losses of negative-regulatory TCR coreceptors (eg, CTLA4). TCR stimulation of T-PLL cells evoked higher-than-normal cell-cycle transition and profiles of cytokine release that resembled those of normal memory T cells. More activated phenotypes and higher TCL1A correlated with inferior clinical outcomes. TCL1A was linked to the marked resistance of T-PLL to activation- and FAS-induced cell death. Enforced TCL1A enhanced phospho-activation of TCR kinases, second-messenger generation, and JAK/STAT or NFAT transcriptional responses. This reduced the input thresholds for IL-2 secretion in a sensitizer-like fashion. Mice of TCL1A-initiated protracted T-PLL development resembled such features. When equipped with epitope-defined TCRs or chimeric antigen receptors, these Lckpr-hTCL1Atg T cells gained a leukemogenic growth advantage in scenarios of receptor stimulation. Overall, we propose a model of T-PLL pathogenesis in which TCL1A enhances TCR signals and drives the accumulation of death-resistant memory-type cells that use amplified low-level stimulatory input, and whose loss of negative coregulators additionally maintains their activated state. Treatment rationales are provided by combined interception in TCR and survival signaling.


Assuntos
Memória Imunológica , Leucemia Prolinfocítica de Células T/imunologia , Proteínas Proto-Oncogênicas/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Animais , Humanos , Leucemia Prolinfocítica de Células T/genética , Leucemia Prolinfocítica de Células T/patologia , Camundongos , Camundongos Knockout , Proteínas Proto-Oncogênicas/genética , Receptores de Antígenos de Linfócitos T/genética , Transdução de Sinais/genética , Linfócitos T/patologia
4.
Nat Commun ; 9(1): 697, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29449575

RESUMO

T-cell prolymphocytic leukemia (T-PLL) is a rare and poor-prognostic mature T-cell malignancy. Here we integrated large-scale profiling data of alterations in gene expression, allelic copy number (CN), and nucleotide sequences in 111 well-characterized patients. Besides prominent signatures of T-cell activation and prevalent clonal variants, we also identify novel hot-spots for CN variability, fusion molecules, alternative transcripts, and progression-associated dynamics. The overall lesional spectrum of T-PLL is mainly annotated to axes of DNA damage responses, T-cell receptor/cytokine signaling, and histone modulation. We formulate a multi-dimensional model of T-PLL pathogenesis centered around a unique combination of TCL1 overexpression with damaging ATM aberrations as initiating core lesions. The effects imposed by TCL1 cooperate with compromised ATM toward a leukemogenic phenotype of impaired DNA damage processing. Dysfunctional ATM appears inefficient in alleviating elevated redox burdens and telomere attrition and in evoking a p53-dependent apoptotic response to genotoxic insults. As non-genotoxic strategies, synergistic combinations of p53 reactivators and deacetylase inhibitors reinstate such cell death execution.


Assuntos
Proteínas Mutadas de Ataxia Telangiectasia/genética , Dano ao DNA , Epigênese Genética , Leucemia Prolinfocítica de Células T/genética , Proteínas Proto-Oncogênicas/genética , Adulto , Idoso , Animais , Proteínas Mutadas de Ataxia Telangiectasia/metabolismo , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica/métodos , Células HEK293 , Humanos , Estimativa de Kaplan-Meier , Leucemia Prolinfocítica de Células T/tratamento farmacológico , Leucemia Prolinfocítica de Células T/metabolismo , Masculino , Camundongos Transgênicos , Pessoa de Meia-Idade , Mutação , Proteínas Proto-Oncogênicas/metabolismo
5.
Leukemia ; 32(5): 1070-1080, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29467486

RESUMO

In chronic lymphocytic leukemia (CLL), TP53 gene defects, due to deletion of the 17p13 locus and/or mutation(s) within the TP53 gene, are associated with resistance to chemoimmunotherapy and a particularly dismal clinical outcome. On these grounds, analysis of TP53 aberrations has been incorporated into routine clinical diagnostics to improve patient stratification and optimize therapeutic decisions. The predictive implications of TP53 aberrations have increasing significance in the era of novel targeted therapies, i.e., inhibitors of B-cell receptor (BcR) signaling and anti-apoptotic BCL2 family members, owing to their efficacy in patients with TP53 defects. In this report, the TP53 Network of the European Research Initiative on Chronic Lymphocytic Leukemia (ERIC) presents updated recommendations on the methodological approaches for TP53 mutation analysis. Moreover, it provides guidance to ensure that the analysis is performed in a timely manner for all patients requiring treatment and that the data is interpreted and reported in a consistent, standardized, and accurate way. Since next-generation sequencing technologies are gaining prominence within diagnostic laboratories, this report also offers advice and recommendations for the interpretation of TP53 mutation data generated by this methodology.


Assuntos
Análise Mutacional de DNA/métodos , Genes p53/genética , Leucemia Linfocítica Crônica de Células B/genética , Europa (Continente) , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos
6.
Leukemia ; 32(2): 364-375, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28804121

RESUMO

Somatic hypermutation (SHM) is a pivotal process in adaptive immunity that occurs in the germinal centre and allows B cells to change their primary DNA sequence and diversify their antigen receptors. Here, we report that genome binding of Lamin B1, a component of the nuclear envelope involved in epigenetic chromatin regulation, is reduced during B-cell activation and formation of lymphoid germinal centres. Chromatin immunoprecipitation-Seq analysis showed that kappa and heavy variable immunoglobulin domains were released from the Lamin B1 suppressive environment when SHM was induced in B cells. RNA interference-mediated reduction of Lamin B1 resulted in spontaneous SHM as well as kappa-light chain aberrant surface expression. Finally, Lamin B1 expression level correlated with progression-free and overall survival in chronic lymphocytic leukaemia, and was strongly involved in the transformation of follicular lymphoma. In summary, here we report that Lamin B1 is a negative epigenetic regulator of SHM in normal B-cells and a 'mutational gatekeeper', suppressing the aberrant mutations that drive lymphoid malignancy.


Assuntos
Linfócitos B/patologia , Lamina Tipo B/genética , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Hipermutação Somática de Imunoglobulina/genética , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina/métodos , Progressão da Doença , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Linfoma Folicular/genética , Linfoma Folicular/patologia
11.
Leukemia ; 31(5): 1177-1186, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27773933

RESUMO

Treatment resistance becomes a challenge at some point in the course of most patients with chronic lymphocytic leukemia (CLL). This applies to fludarabine-based regimens, and is also an increasing concern in the era of more targeted therapies. As cells with low-replicative activity rely on repair that triggers checkpoint-independent noncanonical pathways, we reasoned that targeting the nucleotide excision repair (NER) reaction addresses a vulnerability of CLL and might even synergize with fludarabine, which blocks the NER gap-filling step. We interrogated here especially the replication-independent transcription-coupled-NER ((TC)-NER) in prospective trial patients, primary CLL cultures, cell lines and mice. We screen selected (TC)-NER-targeting compounds as experimental (illudins) or clinically approved (trabectedin) drugs. They inflict transcription-stalling DNA lesions requiring TC-NER either for their removal (illudins) or for generation of lethal strand breaks (trabectedin). Genetically defined systems of NER deficiency confirmed their specificity. They selectively and efficiently induced cell death in CLL, irrespective of high-risk cytogenetics, IGHV status or clinical treatment history, including resistance. The substances induced ATM/p53-independent apoptosis and showed marked synergisms with fludarabine. Trabectedin additionally perturbed stromal-cell protection and showed encouraging antileukemic profiles even in aggressive and transforming murine CLL. This proof-of-principle study established (TC)-NER as a mechanism to be further exploited to resensitize CLL cells.


Assuntos
Reparo do DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Leucemia Linfocítica Crônica de Células B/genética , Transcrição Gênica , Animais , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Ensaios Clínicos como Assunto , Dioxóis/uso terapêutico , Sinergismo Farmacológico , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Camundongos , Tetra-Hidroisoquinolinas/uso terapêutico , Trabectedina , Células Tumorais Cultivadas , Vidarabina/análogos & derivados , Vidarabina/uso terapêutico
12.
Leukemia ; 30(11): 2179-2186, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27282254

RESUMO

Histone methyltransferases (HMTs) are important epigenetic regulators of gene transcription and are disrupted at the genomic level in a spectrum of human tumours including haematological malignancies. Using high-resolution single nucleotide polymorphism (SNP) arrays, we identified recurrent deletions of the SETD2 locus in 3% (8/261) of chronic lymphocytic leukaemia (CLL) patients. Further validation in two independent cohorts showed that SETD2 deletions were associated with loss of TP53, genomic complexity and chromothripsis. With next-generation sequencing we detected mutations of SETD2 in an additional 3.8% of patients (23/602). In most cases, SETD2 deletions or mutations were often observed as a clonal event and always as a mono-allelic lesion, leading to reduced mRNA expression in SETD2-disrupted cases. Patients with SETD2 abnormalities and wild-type TP53 and ATM from five clinical trials employing chemotherapy or chemo-immunotherapy had reduced progression-free and overall survival compared with cases wild type for all three genes. Consistent with its postulated role as a tumour suppressor, our data highlight SETD2 aberration as a recurrent, early loss-of-function event in CLL pathobiology linked to aggressive disease.


Assuntos
Genômica , Histona-Lisina N-Metiltransferase/genética , Leucemia Linfocítica Crônica de Células B/genética , Mutação , Proteínas Mutadas de Ataxia Telangiectasia/genética , Intervalo Livre de Doença , Feminino , Genes Supressores de Tumor , Histona Metiltransferases , Humanos , Leucemia Linfocítica Crônica de Células B/enzimologia , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Prognóstico , Taxa de Sobrevida , Proteína Supressora de Tumor p53/genética
13.
Leukemia ; 30(10): 2019-2025, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27133817

RESUMO

This study aimed to assess the frequency of and the contributing factors for second primary malignancies (SPMs) and Richter's transformations (RTs) following first-line treatment of chronic lymphocytic leukemia within four phase II/III trials of the GCLLSG evaluating fludarabine (F) vs F+cyclophosphamide (FC), chlorambucil vs F, FC without or with rituximab, and bendamustine+R (BR). Among 1458 patients, 239 (16.4%) experienced either an SPM (N=191) or a RT (N=75). Solid tumors (N=115; 43.2% of all second neoplasias) appeared most frequently, followed by RTs (N=75; 28.2%). Patients showed a 1.23-fold increased risk of solid tumors in comparison to the age-matched general population from the German cancer registry. Age>65 (hazard ratio (HR) 2.1; P<0.001), male sex (HR 1.7; P=0.01), co-morbidities (HR 1.6; P=0.01) and number of subsequent treatments⩾1 (HR 12.1; P<0.001) showed an independent adverse prognostic impact on SPM-free survival. Serum thymidine kinase>10 U/l at trial enrollment (HR 3.9; P=0.02), non-response to first-line treatment (HR 3.6; P<0.001) and number of subsequent treatments⩾1 (HR 30.2; P<0.001) were independently associated with increased risk for RT.


Assuntos
Transformação Celular Neoplásica/induzido quimicamente , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Segunda Neoplasia Primária/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Cloridrato de Bendamustina/administração & dosagem , Cloridrato de Bendamustina/uso terapêutico , Estudos de Casos e Controles , Clorambucila/administração & dosagem , Clorambucila/uso terapêutico , Ciclofosfamida/administração & dosagem , Ciclofosfamida/uso terapêutico , Intervalo Livre de Doença , Feminino , Alemanha , Humanos , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Segunda Neoplasia Primária/mortalidade , Sistema de Registros , Medição de Risco , Fatores de Risco , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados , Vidarabina/uso terapêutico
15.
Blood Cancer J ; 6: e404, 2016 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-26967821

RESUMO

Efficacy of lenalidomide was investigated in 103 patients with relapsed/refractory chronic lymphocytic leukemia (CLL) treated on the prospective, multicenter randomized phase-II CLL-009 trial. Interphase cytogenetic and mutational analyses identified TP53 mutations, unmutated IGHV, or del(17p) in 36/96 (37.5%), 68/88 (77.3%) or 22/92 (23.9%) patients. The overall response rate (ORR) was 40.4% (42/104). ORRs were similar irrespective of TP53 mutation (36.1% (13/36) vs 43.3% (26/60) for patients with vs without mutation) or IGHV mutation status (45.0% (9/20) vs 39.1% (27/68)); however, patients with del(17p) had lower ORRs than those without del(17p) (21.7% (5/22) vs 47.1% (33/70); P=0.049). No significant differences in progression-free survival and overall survival (OS) were observed when comparing subgroups defined by the presence or absence of high-risk genetic characteristics. In multivariate analyses, only multiple prior therapies (⩾3 lines) significantly impacted outcomes (median OS: 21.2 months vs not reached; P=0.019). This analysis indicates that lenalidomide is active in patients with relapsed/refractory CLL with unfavorable genetic profiles, including TP53 inactivation or unmutated IGHV. (ClinicalTrials.gov identifier: NCT00963105).


Assuntos
Antineoplásicos/uso terapêutico , Resistencia a Medicamentos Antineoplásicos , Fatores Imunológicos/uso terapêutico , Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Talidomida/análogos & derivados , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Lenalidomida , Leucemia Linfocítica Crônica de Células B/genética , Masculino , Pessoa de Meia-Idade , Mutação , Prognóstico , Recidiva , Retratamento , Análise de Sobrevida , Talidomida/uso terapêutico , Resultado do Tratamento , Proteína Supressora de Tumor p53/genética
16.
Cell Death Dis ; 7: e2052, 2016 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-26775704

RESUMO

SMAC-mimetics represent a targeted therapy approach to overcome apoptosis resistance in many tumors. Here, we investigated the efficacy of the SMAC-mimetic BV6 in B-cell precursor acute lymphoblastic leukemia (BCP-ALL). In ALL cell lines, intrinsic apoptosis sensitivity was associated with rapid cIAP degradation, NF-κB activation, TNF-α secretion and induction of an autocrine TNF-α-dependent cell death loop. This pattern of responsiveness was also observed upon ex vivo analysis of 40 primograft BCP-ALL samples. Treatment with BV6 induced cell death in the majority of ALL primografts including leukemias with high-risk and poor-prognosis features. Inhibition of cell death by the TNF receptor fusion protein etanercept demonstrated that BV6 activity is dependent on TNF-α. In a preclinical NOD/SCID/huALL model of high-risk ALL, marked anti-leukemia effectivity and significantly prolonged survival were observed upon BV6 treatment. Interestingly, also in vivo, intrinsic SMAC-mimetic activity was mediated by TNF-α. Importantly, BV6 increased the effectivity of conventional induction therapy including vincristine, dexamethasone and asparaginase leading to prolonged remission induction. These data suggest SMAC-mimetics as an important addendum to efficient therapy of pediatric BCP-ALL.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Apoptose , Morte Celular , Linhagem Celular Tumoral , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Fatores de Risco , Transdução de Sinais
17.
Leukemia ; 29(10): 2003-14, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25936528

RESUMO

Dysregulated T-cell leukemia/lymphoma-1A (TCL1A), a modulator in B-cell receptor (BCR) signaling, is causally implicated in chronic lymphocytic leukemia (CLL). However, the mechanisms of the perturbed TCL1A regulation are largely unknown. To characterize TCL1A-upstream networks, we functionally screened for TCL1A-repressive micro-RNAs (miRs) and their transcriptional regulators. We identified the novel miR-484 to target TCL1A's 3'-UTR and to be downregulated in CLL. In chromatin immunoprecipitations and reporter assays, the oncogenic transcription factor of myeloid cells, EVI1, bound and activated the miR-484 promoter. Most common in CLL was a pan-EVI1 transcript variant. EVI1 protein expression revealed distinct normal-tissue and leukemia-associated patterns of EVI1/TCL1A co-regulation. EVI1 levels were particularly low in TCL1A-high CLL or such cellular subsets. Global gene expression profiles from a 337-patient set linked EVI1 networks to BCR signaling and cell survival via TCL1A, BTK and other molecules of relevance in CLL. Enforced EVI1, as did miR-484, repressed TCL1A. Furthermore, it reduced phospho-kinase levels, impaired cell survival, mitigated BCR-induced Ca-flux and diminished the in vitro ibrutinib response. Moreover, TCL1A and EVI1 showed a strongly interactive hazard prediction in prospectively treated patients. Overall, we present regressive EVI1 as a novel regulatory signature in CLL. Through enhanced TCL1A and other EVI1-targeted hallmarks of CLL, this contributes to an aggressive cellular and clinical phenotype.


Assuntos
Apoptose , Proteínas de Ligação a DNA/metabolismo , Regulação Leucêmica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/mortalidade , MicroRNAs/genética , Proteínas Proto-Oncogênicas/metabolismo , Fatores de Transcrição/metabolismo , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Estudos de Casos e Controles , Proliferação de Células , Imunoprecipitação da Cromatina , Proteínas de Ligação a DNA/genética , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Leucemia Linfocítica Crônica de Células B/patologia , Proteína do Locus do Complexo MDS1 e EVI1 , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes/genética , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Taxa de Sobrevida , Fatores de Transcrição/genética , Células Tumorais Cultivadas
18.
Leukemia ; 29(2): 329-36, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24943832

RESUMO

Through the European Research Initiative on chronic lymphocytic leukemia (CLL) (ERIC), we screened 3490 patients with CLL for mutations within the NOTCH1 (n=3334), SF3B1 (n=2322), TP53 (n=2309), MYD88 (n=1080) and BIRC3 (n=919) genes, mainly at diagnosis (75%) and before treatment (>90%). BIRC3 mutations (2.5%) were associated with unmutated IGHV genes (U-CLL), del(11q) and trisomy 12, whereas MYD88 mutations (2.2%) were exclusively found among M-CLL. NOTCH1, SF3B1 and TP53 exhibited variable frequencies and were mostly enriched within clinically aggressive cases. Interestingly, as the timespan between diagnosis and mutational screening increased, so too did the incidence of SF3B1 mutations; no such increase was observed for NOTCH1 mutations. Regarding the clinical impact, NOTCH1 mutations, SF3B1 mutations and TP53 aberrations (deletion/mutation, TP53ab) correlated with shorter time-to-first-treatment (P<0.0001) in 889 treatment-naive Binet stage A cases. In multivariate analysis (n=774), SF3B1 mutations and TP53ab along with del(11q) and U-CLL, but not NOTCH1 mutations, retained independent significance. Importantly, TP53ab and SF3B1 mutations had an adverse impact even in U-CLL. In conclusion, we support the clinical relevance of novel recurrent mutations in CLL, highlighting the adverse impact of SF3B1 and TP53 mutations, even independent of IGHV mutational status, thus underscoring the need for urgent standardization/harmonization of the detection methods.


Assuntos
Leucemia Linfocítica Crônica de Células B/diagnóstico , Leucemia Linfocítica Crônica de Células B/genética , Mutação , Idoso , Citogenética , Análise Mutacional de DNA , Europa (Continente) , Feminino , Deleção de Genes , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Fosfoproteínas/genética , Polimorfismo de Nucleotídeo Único , Prognóstico , Fatores de Processamento de RNA , Receptor Notch1/genética , Recidiva , Ribonucleoproteína Nuclear Pequena U2/genética , Fatores de Tempo , Proteína Supressora de Tumor p53/genética
19.
Internist (Berl) ; 55(12): 1400, 1402-4, 1406-9, 2014 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-25392275

RESUMO

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the western world and affects mainly elderly patients. In current phase III trials, standard treatment options were established that differ mainly based on the fitness and age of the patient. The combination of fludarabine, cyclophosphamide, and the CD20 antibody rituximab (FCR) is recommended for young patients without relevant comorbidity, while bendamustine and rituximab (BR) should be favored for elderly (ca. >65 years) fit individuals. Bendamustine plus ofatumumab is another option in this situation. Patients with major comorbidities should receive chlorambucil combined with CD20 antibody (obinutuzumab or ofatumumab). In 2014, several new compounds were approved for patients with ultrahigh risk genetic factors (17p-, TP53mut) and for relapsed/refractory CLL: both idelalisib and ibrutinib are orally bioavailable kinase inhibitors that block key regulators of central pathways. For both agents, very impressive data are available with regard to tolerability and efficacy that will change the treatment paradigm in CLL. With ABT-199, a direct apoptosis inducer is being developed that in early clinical trials produced high remission rates combined with good tolerability. Combinations and sequences of the "novel" compounds obinutuzumab, ofatumumab, idelalisib, ibrutinib, and ABT-199 will be studied in coming years in clinical trials in order to prolong remission duration and reduce side effects with the eventual aim of curing CLL.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/patologia , Oncologia/métodos , Guias de Prática Clínica como Assunto , Sulfonamidas/uso terapêutico , Medicina Baseada em Evidências , Alemanha , Humanos , Resultado do Tratamento
20.
Leukemia ; 28(6): 1289-98, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24280868

RESUMO

Chronic lymphocytic leukemia (CLL) is an incurable malignancy of mature B cells. One of the major challenges in treatment of CLL is the achievement of a complete remission to prevent relapse of disease originating from cells within lymphoid tissues and subsequent chemoresistance. In search for novel drugs that target CLL cells in protective microenvironments, we performed a fungal extract screen using cocultures of primary CLL cells with bone marrow-derived stromal cells. A secondary metabolite produced by Penicillium aquamarinium was identified as Chaetoglobosin A (ChA), a member of the cytochalasan family that showed preferential induction of apoptosis in CLL cells, even under culture conditions that mimic lymphoid tissues. In vitro testing of 89 CLL cases revealed effective targeting of CLL cells by ChA, independent of bad prognosis characteristics, like 17p deletion or TP53 mutation. To provide insight into its mechanism of action, we showed that ChA targets filamentous actin in CLL cells and thereby induces cell-cycle arrest and inhibits membrane ruffling and cell migration. Our data further revealed that ChA prevents CLL cell activation and sensitizes them for treatment with PI3K and BTK inhibitors, suggesting this compound as a novel potential drug for CLL.


Assuntos
Apoptose/efeitos dos fármacos , Citocinese/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Alcaloides Indólicos/farmacologia , Leucemia Linfocítica Crônica de Células B/patologia , Micotoxinas/farmacologia , Células Estromais/efeitos dos fármacos , Actinas/metabolismo , Western Blotting , Estudos de Casos e Controles , Adesão Celular/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Técnicas de Cocultura , Citoesqueleto/metabolismo , Citometria de Fluxo , Fungos/química , Voluntários Saudáveis , Humanos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Células Estromais/metabolismo , Células Estromais/patologia , Células Tumorais Cultivadas
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