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1.
Eur J Cancer ; 132: 11-16, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32305831

RESUMO

INTRODUCTION: Since the beginning of COVID-19 pandemic, it is known that the severe course of the disease occurs mostly among the elderly, whereas it is rare among children and young adults. Comorbidities, in particular, diabetes and hypertension, clearly associated with age, besides obesity and smoke, are strongly associated with the need for intensive treatment and a dismal outcome. A weaker immunity of the elderly has been proposed as a possible explanation of this uneven age distribution. Thus, there is concern that children treated for cancer may allso be at risk for an unfavourable course of infection. Along the same line, anecdotal information from Wuhan, China, mentioned a severe course of COVID-19 in a child treated for leukaemia. AIM AND METHODS: We made a flash survey on COVID-19 incidence and severity among children on anticancer treatment. Respondents were asked by email to fill in a short Web-based survey. RESULTS: We received reports from 25 countries, where approximately 10,000 patients at risk are followed up. At the time of the survey, more than 200 of these children were tested, nine of whom were positive for COVID-19. Eight of the nine cases had asymptomatic to mild disease, and one was just diagnosed with COVID-19. We also discuss preventive measures that are in place or should be taken and treatment options in immunocompromised children with COVID-19. CONCLUSION: Thus, even children receiving anticancer chemotherapy may have a mild or asymptomatic course of COVID-19. While we should not underestimate the risk of developing a more severe course of COVID-19 than that observed here, the intensity of preventive measures should not cause delays or obstructions in oncological treatment.

2.
Ann Hematol ; 99(4): 809-818, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32078009

RESUMO

Risk-adapted therapy has significantly contributed to improved survival rates in pediatric acute lymphoblastic leukemia (ALL) and reliable detection of chromosomal aberrations is mandatory for risk group stratification. This study evaluated the applicability of panel-based RNA sequencing and array CGH within the diagnostic workflow of the German study group of the international AIEOP-BFM ALL 2017 trial. In a consecutive cohort of 117 children with B cell precursor (BCP) ALL, array analysis identified twelve cases with an IKZF1plus profile of gene deletions and one case of masked hypodiploidy. Genetic markers BCR-ABL1 (n = 1), ETV6-RUNX1 (n = 25), and rearrangements involving KMT2A (n = 3) or TCF3 (n = 3) were assessed by established conventional techniques such as karyotyping, FISH, and RT-PCR. Comparison of these results with RNA sequencing analysis revealed overall consistency in n=115/117 cases, albeit with one undetected AFF1-KMT2A fusion in RNA sequencing and one undetected ETV6-RUNX1 fusion in conventional analyses. The combined application of RNA sequencing, FISH, and CGH+SNP array reliably detected all genetic markers necessary for risk stratification and will be used as the diagnostic standard workflow for BCP-ALL patients enrolled in the AIEOP-BFM ALL 2017 study. Prospectively, consistent collection of genome-wide CGH+SNP array as well as RNA sequencing data will be a valuable source to elucidate new prognostic lesions beyond established markers of pediatric ALL. In this respect, RNA sequencing identified various gene fusions in up to half of the IKZF1plus (n = 6/12) and B-other (n = 19/36) cases but not in cases with hyperdiploid karyotypes (n = 35). Among these fusions, this study reports several previously undescribed in frame PAX5 fusions, including PAX5-MYO1G and PAX5-NCOA6.


Assuntos
Hibridização Genômica Comparativa , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , RNA Mensageiro/análise , RNA Neoplásico/análise , Análise de Sequência de RNA , Cariótipo Anormal , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Asparaginase/administração & dosagem , Ciclofosfamida/administração & dosagem , Citarabina/administração & dosagem , Daunorrubicina/administração & dosagem , Genes Neoplásicos , Humanos , Fator de Transcrição Ikaros/genética , Hibridização in Situ Fluorescente , Mercaptopurina/administração & dosagem , Metotrexato/administração & dosagem , Proteínas de Neoplasias/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Prednisona/administração & dosagem , Estudos Prospectivos , Fatores de Risco , Transcriptoma , Vincristina/administração & dosagem , Fluxo de Trabalho
3.
Blood ; 135(4): 252-260, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31821407

RESUMO

Improved personalized adjustment of primary therapy to the perceived risk of relapse by using new prognostic markers for treatment stratification may be beneficial to patients with acute lymphoblastic leukemia (ALL). Here, we review the advances that have shed light on the role of IKZF1 aberration as prognostic factor in pediatric ALL and summarize emerging concepts in this field. Continued research on the interplay of disease biology with exposure and response to treatment will be key to further improve treatment strategies.

4.
Nat Commun ; 10(1): 5348, 2019 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-31767839

RESUMO

There is increasing evidence for a strong inherited genetic basis of susceptibility to acute lymphoblastic leukaemia (ALL) in children. To identify new risk variants for B-cell ALL (B-ALL) we conducted a meta-analysis with four GWAS (genome-wide association studies), totalling 5321 cases and 16,666 controls of European descent. We herein describe novel risk loci for B-ALL at 9q21.31 (rs76925697, P = 2.11 × 10-8), for high-hyperdiploid ALL at 5q31.1 (rs886285, P = 1.56 × 10-8) and 6p21.31 (rs210143 in BAK1, P = 2.21 × 10-8), and ETV6-RUNX1 ALL at 17q21.32 (rs10853104 in IGF2BP1, P = 1.82 × 10-8). Particularly notable are the pleiotropic effects of the BAK1 variant on multiple haematological malignancies and specific effects of IGF2BP1 on ETV6-RUNX1 ALL evidenced by both germline and somatic genomic analyses. Integration of GWAS signals with transcriptomic/epigenomic profiling and 3D chromatin interaction data for these leukaemia risk loci suggests deregulation of B-cell development and the cell cycle as central mechanisms governing genetic susceptibility to ALL.

5.
Cancer Cell ; 36(6): 630-644.e9, 2019 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-31735627

RESUMO

The chimeric transcription factor TCF3-HLF defines an incurable acute lymphoblastic leukemia subtype. Here we decipher the regulome of endogenous TCF3-HLF and dissect its essential transcriptional components and targets by functional genomics. We demonstrate that TCF3-HLF recruits HLF binding sites at hematopoietic stem cell/myeloid lineage associated (super-) enhancers to drive lineage identity and self-renewal. Among direct targets, hijacking an HLF binding site in a MYC enhancer cluster by TCF3-HLF activates a conserved MYC-driven transformation program crucial for leukemia propagation in vivo. TCF3-HLF pioneers the cooperation with ERG and recruits histone acetyltransferase p300 (EP300), conferring susceptibility to EP300 inhibition. Our study provides a framework for targeting driving transcriptional dependencies in this fatal leukemia.

6.
Haematologica ; 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601692

RESUMO

ABL-class fusions other than BCR-ABL1 characterize about 2-3% of precursor B-cell acute lymphoblastic leukemia. Case series indicated that patients suffering from these subtypes have a dismal outcome and may benefit from the introduction of tyrosine kinase inhibitors. We analyzed clinical characteristics and outcome of 46 ABL-class fusion positive cases other than BCR-ABL1 treated according to AIEOP-BFM ALL 2000 and 2009 protocols; 13 of them received a tyrosine kinase inhibitor during different phases of treatment. ABL-class fusion positive cases had a poor early treatment response: minimal residual disease levels of >5x10-4 were observed in 71.4% of patients after induction treatment and in 51.2% after consolidation phase. For the entire cohort of 46 cases the 5-year probability of event-free survival was 49.1+8.9% and that of overall survival 69.6+7.8%; the cumulative incidence of relapse was 25.6+8.2% and treatment-related mortality 20.8+6.8%. One out of 13 cases with tyrosine kinase inhibitor added to chemotherapy relapsed while eight of 33 cases without tyrosine kinase inhibitor treatment suffered from relapse, including six in 17 patients who had not received hematopoietic stem cell transplantation. Stem cell transplantation seems to be effective in preventing relapses (only three relapses in 25 patients), but was associated with a very high treatment-related mortality (6 patients). These data indicate a major need for an early identification of ABL-class fusion positive acute lymphoblastic leukemia cases and to establish a properly designed, controlled study aimed at investigating the use of tyrosine kinase inhibitors, the appropriate chemotherapy backbone and the role of hematopoietic stem cell transplantation. (ClinicalTrials.gov identifier: NTC00430118, NCT00613457, NCT01117441).

7.
Blood Adv ; 3(20): 3143-3156, 2019 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-31648313

RESUMO

Survival of patients with pediatric acute lymphoblastic leukemia (ALL) after allogeneic hematopoietic stem cell transplantation (allo-SCT) is mainly compromised by leukemia relapse, carrying dismal prognosis. As novel individualized therapeutic approaches are urgently needed, we performed whole-exome sequencing of leukemic blasts of 10 children with post-allo-SCT relapses with the aim of thoroughly characterizing the mutational landscape and identifying druggable mutations. We found that post-allo-SCT ALL relapses display highly diverse and mostly patient-individual genetic lesions. Moreover, mutational cluster analysis showed substantial clonal dynamics during leukemia progression from initial diagnosis to relapse after allo-SCT. Only very few alterations stayed constant over time. This dynamic clonality was exemplified by the detection of thiopurine resistance-mediating mutations in the nucleotidase NT5C2 in 3 patients' first relapses, which disappeared in the post-allo-SCT relapses on relief of selective pressure of maintenance chemotherapy. Moreover, we identified TP53 mutations in 4 of 10 patients after allo-SCT, reflecting acquired chemoresistance associated with selective pressure of prior antineoplastic treatment. Finally, in 9 of 10 children's post-allo-SCT relapse, we found alterations in genes for which targeted therapies with novel agents are readily available. We could show efficient targeting of leukemic blasts by APR-246 in 2 patients carrying TP53 mutations. Our findings shed light on the genetic basis of post-allo-SCT relapse and may pave the way for unraveling novel therapeutic strategies in this challenging situation.

8.
Haematologica ; 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371414

RESUMO

Children with Down syndrome and acute lymphoblastic leukemia often suffer from severe toxicities during treatment, especially with high-dose methotrexate. Systematic data on methotrexate toxicity in these patients are rare. We analyzed seven methotrexate-associated toxicities during consolidation therapy in 103 Down-syndrome- and 1,109 Non-Down-syndrome-patients with acute lymphoblastic leukemia enrolled in ALL-BFM trials between 1995-2016 and 1995-2007, respectively. Patients received four courses methotrexate (5 g/m2 each) plus intrathecal methotrexate and 6-mercaptopurine. From 2004 on, a dose of 0.5 g/m2 in the 1st methotrexate course was recommended for Down-syndrome-patients. Down-syndrome-patients showed higher rates of 3/4 toxicities after the 1st course with 5 g/m2 methotrexate compared to Non-Down-syndrome-patients (62 3/4 toxicities in 45 Down-syndrome- vs. 516 in 1,089 Non-Down-syndrome-patients, p<0.001). Dose reduction (0.5 g/m2) in Down-syndrome-patients reduced toxicity (39 in 51 patients, p<0.001) without increasing the relapse risk (reduced dose, 5 year cumulative relapse incidence = 0.09+/-0.04 vs. high dose, 0.10+/-0.05, p=0.51). Methotrexate dose escalation to 1.0 g/m2 for Down-syndrome-patients who tolerated 0.5 g/m2 (n= 28/51 patients) did not result in an increased rate of 3/4 toxicities after the 2nd course (p=0.285). Differences in methotrexate plasma levels at 42 h and 48 h after start of the 1st methotrexate infusion did not explain higher toxicity rates in Down-syndrome-patients treated with 0.5 g/m2 as compared to Non-Down-syndrome-patients treated with 5 g/m2. Within the Down-syndrome cohort a higher methotrexate plasma level was associated with increased toxicity. In conclusion, dose reduction in the 1st methotrexate course reduced severe toxicities without increasing the risk of relapse.

10.
Cancer Cell ; 35(4): 664-676.e7, 2019 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-30991026

RESUMO

Resistance to asparaginase, an antileukemic enzyme that depletes asparagine, is a common clinical problem. Using a genome-wide CRISPR/Cas9 screen, we found a synthetic lethal interaction between Wnt pathway activation and asparaginase in acute leukemias resistant to this enzyme. Wnt pathway activation induced asparaginase sensitivity in distinct treatment-resistant subtypes of acute leukemia, but not in normal hematopoietic progenitors. Sensitization to asparaginase was mediated by Wnt-dependent stabilization of proteins (Wnt/STOP), which inhibits glycogen synthase kinase 3 (GSK3)-dependent protein ubiquitination and proteasomal degradation, a catabolic source of asparagine. Inhibiting the alpha isoform of GSK3 phenocopied this effect, and pharmacologic GSK3α inhibition profoundly sensitized drug-resistant leukemias to asparaginase. Our findings provide a molecular rationale for activation of Wnt/STOP signaling to improve the therapeutic index of asparaginase.


Assuntos
Antineoplásicos/farmacologia , Asparaginase/farmacologia , Resistencia a Medicamentos Antineoplásicos , Leucemia/tratamento farmacológico , Polietilenoglicóis/farmacologia , Mutações Sintéticas Letais , Via de Sinalização Wnt/genética , Proteína Wnt3A/genética , Animais , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glicogênio Sintase Quinase 3 beta/antagonistas & inibidores , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Células Jurkat , Leucemia/genética , Leucemia/metabolismo , Leucemia/patologia , Masculino , Camundongos Endogâmicos NOD , Camundongos Transgênicos , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Estabilidade Proteica , Proteólise , Células THP-1 , Ubiquitinação , Proteína Wnt3A/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Genet Med ; 21(9): 2145-2150, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-30728528

RESUMO

PURPOSE: Severe hematotoxicity in patients with thiopurine therapy has been associated with genetic polymorphisms in the thiopurine S-methyltransferase (TPMT). While TPMT genetic testing is clinically implemented for dose individualization, alterations in the nudix hydrolase 15 (NUDT15) emerged as independent determinant of thiopurine-related hematotoxicity. Because data for European patients are limited, we investigated the relevance of NUDT15 in Europeans. METHODS: Additionally to TPMT phenotyping/genotyping, we performed in-depth Sanger sequencing analyses of NUDT15 coding region in 107 European patients who developed severe thiopurine-related hematotoxicity as extreme phenotype. Moreover, genotyping for NUDT15 variants in 689 acute lymphoblastic leukemia (ALL) patients was performed. RESULTS: As expected TPMT was the main cause of severe hematotoxicity in 31% of patients, who were either TPMT deficient (10%) or heterozygous carriers of TPMT variants (21%). By comparison, NUDT15 genetic polymorphism was identified in 14 (13%) patients including one novel variant (p.Met1Ile). Six percent of patients with severe toxicity carried variants in both TPMT and NUDT15. Among patients who developed toxicity within 3 months of treatment, 13% were found to be carriers of NUDT15 variants. CONCLUSION: Taken together, NUDT15 and TPMT genetics explain ~50% of severe thiopurine-related hematotoxicity, providing a compelling rationale for additional preemptive testing of NUDT15 genetics not only in Asians, but also in Europeans.


Assuntos
Hipersensibilidade a Drogas/genética , Metiltransferases/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Erros Inatos do Metabolismo da Purina-Pirimidina/genética , Pirofosfatases/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Hipersensibilidade a Drogas/etiologia , Hipersensibilidade a Drogas/patologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/genética , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/patologia , Feminino , Predisposição Genética para Doença , Testes Genéticos/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Erros Inatos do Metabolismo da Purina-Pirimidina/patologia
13.
Nat Commun ; 10(1): 419, 2019 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-30664635

RESUMO

The original version of this Article contained an error in the spelling of a member of the PRACTICAL Consortium, Manuela Gago-Dominguez, which was incorrectly given as Manuela Gago Dominguez. This has now been corrected in both the PDF and HTML versions of the Article. Furthermore, in the original HTML version of this Article, the order of authors within the author list was incorrect. The PRACTICAL consortium was incorrectly listed after Richard S. Houlston and should have been listed after Nora Pashayan. This error has been corrected in the HTML version of the Article; the PDF version was correct at the time of publication.

14.
Math Med Biol ; 36(4): 471-488, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-30357334

RESUMO

Acute lymphoblastic leukemia is the most common malignancy in childhood and requires prolonged oral maintenance chemotherapy to prevent disease relapse after remission induction with intensive intravenous chemotherapy. In maintenance therapy, drug doses of 6-mercaptopurine (6-MP) and methotrexate (MTX) are adjusted to achieve sustained antileukemic activity without excessive myelosuppression. However, uncertainty exists regarding timing and extent of drug dose responses and optimal dose adaptation strategies. We propose a novel comprehensive mathematical model for 6-MP and MTX pharmacokinetics, pharmacodynamics and myelosuppression in acute lymphoblastic maintenance therapy. We personalize and cross-validate the mathematical model using clinical data and propose a real-time algorithm to predict chemotherapy responses with a clinical decision support system as a potential future application.

15.
Haematologica ; 104(3): 556-563, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30467200

RESUMO

Asparaginase-associated pancreatitis is a life-threatening toxicity to childhood acute lymphoblastic leukemia treatment. To elucidate genetic predisposition and asparaginase-associated pancreatitis pathogenesis, ten trial groups contributed remission samples from patients aged 1.0-17.9 years treated for acute lymphoblastic leukemia between 2000 and 2016. Cases (n=244) were defined by the presence of at least two of the following criteria: (i) abdominal pain; (ii) levels of pancreatic enzymes ≥3 × upper normal limit; and (iii) imaging compatible with pancreatitis. Controls (n=1320) completed intended asparaginase therapy, with 78% receiving ≥8 injections of pegylated-asparaginase, without developing asparaginase-associated pancreatitis. rs62228256 on 20q13.2 showed the strongest association with the development of asparaginase-associated pancreatitis (odds ratio=3.75; P=5.2×10-8). Moreover, rs13228878 (OR=0.61; P=7.1×10-6) and rs10273639 (OR=0.62; P=1.1×10-5) on 7q34 showed significant association with the risk of asparaginase-associated pancreatitis. A Dana Farber Cancer Institute ALL Consortium cohort consisting of patients treated on protocols between 1987 and 2004 (controls=285, cases=33), and the Children's Oncology Group AALL0232 cohort (controls=2653, cases=76) were available as replication cohorts for the 20q13.2 and 7q34 variants, respectively. While rs62228256 was not validated as a risk factor (P=0.77), both rs13228878 (P=0.03) and rs10273639 (P=0.04) were. rs13228878 and rs10273639 are in high linkage disequilibrium (r2=0.94) and associated with elevated expression of the PRSS1 gene, which encodes for trypsinogen, and are known risk variants for alcohol-associated and sporadic pancreatitis in adults. Intra-pancreatic trypsinogen cleavage to proteolytic trypsin induces autodigestion and pancreatitis. In conclusion, this study finds a shared genetic predisposition between asparaginase-associated pancreatitis and non-asparaginase-associated pancreatitis, and targeting the trypsinogen activation pathway may enable identification of effective interventions for asparaginase-associated pancreatitis.

16.
EMBO Mol Med ; 10(12)2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30389682

RESUMO

We compared 24 primary pediatric T-cell acute lymphoblastic leukemias (T-ALL) collected at the time of initial diagnosis and relapse from 12 patients and 24 matched patient-derived xenografts (PDXs). DNA methylation profile was preserved in PDX mice in 97.5% of the promoters (ρ = 0.99). Similarly, the genome-wide chromatin accessibility (ATAC-Seq) was preserved remarkably well (ρ = 0.96). Interestingly, both the ATAC regions, which showed a significant decrease in accessibility in PDXs and the regions hypermethylated in PDXs, were associated with immune response, which might reflect the immune deficiency of the mice and potentially the incomplete interaction between murine cytokines and human receptors. The longitudinal approach of this study allowed an observation that samples collected from patients who developed a type 1 relapse (clonal mutations maintained at relapse) preserved their genomic composition; whereas in patients who developed a type 2 relapse (subset of clonal mutations lost at relapse), the preservation of the leukemia's composition was more variable. In sum, this study underlines the remarkable genomic stability, and for the first time documents the preservation of the epigenomic landscape in T-ALL-derived PDX models.


Assuntos
Regulação da Expressão Gênica , Xenoenxertos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Animais , Humanos , Estudos Longitudinais , Camundongos , Transplante de Neoplasias , Recidiva
17.
Oncotarget ; 9(64): 32362-32372, 2018 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-30190792

RESUMO

Background: While standard RNA expression tests stratify patients into risk groups, RNA-Seq can guide personalized drug selection based on expressed mutations, fusion genes, and differential expression (DE) between tumor and normal tissue. However, patient-matched normal tissue may be unavailable. Additionally, biological variability in normal tissue and technological biases may confound results. Therefore, we present normal expression reference data for two sequencing methods that are suitable for breast biopsies. Results: We identified breast cancer related and drug related genes that are expressed uniformly across our normal samples. Large subsets of these genes are identical for formalin fixed paraffin embedded samples and fresh frozen samples. Adipocyte signatures were detected in frozen compared to formalin samples, prepared by surgeons and pathologists, respectively. Gene expression confounded by adipocytes was identified using fat tissue samples. Finally, immune repertoire statistics were obtained for healthy breast, tumor and fat tissues. Conclusions: Our reference data can be used with patient tumor samples that are asservated and sequenced with a matching aforementioned method. Coefficients of variation are given for normal gene expression. Thus, potential drug selection can be based on confidently overexpressed genes and immune repertoire statistics. Materials and Methods: Normal expression from formalin and frozen healthy breast tissue samples using Roche Kapa RiboErase (total RNA) (19 formalin, 9 frozen) and Illumina TruSeq RNA Access (targeted RNA-Seq, aka TruSeq RNA Exome) (11 formalin, 1 frozen), and fat tissue (6 frozen Access). Tumor DE using 10 formalin total RNA tumor samples and 1 frozen targeted RNA tumor sample.

18.
EMBO J ; 37(14)2018 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-29880602

RESUMO

The impact of LMO2 expression on cell lineage decisions during T-cell leukemogenesis remains largely elusive. Using genetic lineage tracing, we have explored the potential of LMO2 in dictating a T-cell malignant phenotype. We first initiated LMO2 expression in hematopoietic stem/progenitor cells and maintained its expression in all hematopoietic cells. These mice develop exclusively aggressive human-like T-ALL In order to uncover a potential exclusive reprogramming effect of LMO2 in murine hematopoietic stem/progenitor cells, we next showed that transient LMO2 expression is sufficient for oncogenic function and induction of T-ALL The resulting T-ALLs lacked LMO2 and its target-gene expression, and histologically, transcriptionally, and genetically similar to human LMO2-driven T-ALL We next found that during T-ALL development, secondary genomic alterations take place within the thymus. However, the permissiveness for development of T-ALL seems to be associated with wider windows of differentiation than previously appreciated. Restricted Cre-mediated activation of Lmo2 at different stages of B-cell development induces systematically and unexpectedly T-ALL that closely resembled those of their natural counterparts. Together, these results provide a novel paradigm for the generation of tumor T cells through reprogramming in vivo and could be relevant to improve the response of T-ALL to current therapies.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Carcinogênese , Transformação Celular Neoplásica , Proteínas com Domínio LIM/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Animais , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Células-Tronco Hematopoéticas/fisiologia , Histocitoquímica , Camundongos , Timo/patologia
19.
BMC Cancer ; 18(1): 663, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29914415

RESUMO

BACKGROUND: Deletions of 6q15-16.1 are recurrently found in pediatric T-cell acute lymphoblastic leukemia (T-ALL). This chromosomal region includes the mitogen-activated protein kinase kinase kinase 7 (MAP3K7) gene which has a crucial role in innate immune signaling and was observed to be functionally and prognostically relevant in different cancer entities. Therefore, we correlated the presence of MAP3K7 deletions with clinical parameters in a cohort of 327 pediatric T-ALL patients and investigated the function of MAP3K7 in the T-ALL cell lines CCRF-CEM, Jurkat and MOLT-4. METHODS: MAP3K7 deletions were detected by multiplex ligation-dependent probe amplification (MLPA). T-ALL cell lines were transduced with adeno-associated virus (AAV) vectors expressing anti-MAP3K7 shRNA or a non-silencing shRNA together with a GFP reporter. Transduction efficiency was measured by flow cytometry and depletion efficiency by RT-PCR and Western blots. Induction of apoptosis was measured by flow cytometry after staining with PE-conjugated Annexin V. In order to assess the contribution of NF-κB signaling to the effects of MAP3K7 depletion, cells were treated with TNF-α and cell lysates analyzed for components of the NF-κB pathway by Western blotting and for expression of the NF-κB target genes BCL2, CMYC, FAS, PTEN and TNF-α by RT-PCR. RESULTS: MAP3K7 is deleted in approximately 10% and point-mutated in approximately 1% of children with T-ALL. In 32 of 33 leukemias the deletion of MAP3K7 also included the adjacent CASP8AP2 gene. MAP3K7 deletions were associated with the occurrence of SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and outcome. Depletion of MAP3K7 expression in T-ALL cell lines by shRNAs slowed down proliferation and induced apoptosis, but neither changed protein levels of components of NF-κB signaling nor NF-κB target gene expression after stimulation with TNF-α. CONCLUSIONS: This study revealed that the recurrent deletion of MAP3K7/CASP8AP2 is associated with SIL-TAL1 fusions and a mature immunophenotype, but not with response to treatment and risk of relapse. Homozygous deletions of MAP3K7 were not observed, and efficient depletion of MAP3K7 interfered with viability of T-ALL cells, indicating that a residual expression of MAP3K7 is indispensable for T-lymphoblasts.


Assuntos
MAP Quinase Quinase Quinases/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Proteínas Reguladoras de Apoptose/genética , Proteínas de Ligação ao Cálcio/genética , Proliferação de Células/fisiologia , Criança , Pré-Escolar , Feminino , Deleção de Genes , Humanos , Estimativa de Kaplan-Meier , MAP Quinase Quinase Quinases/imunologia , MAP Quinase Quinase Quinases/metabolismo , Masculino , NF-kappa B/metabolismo , Proteínas de Fusão Oncogênica/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patologia , Modelos de Riscos Proporcionais , Resultado do Tratamento
20.
Nat Commun ; 9(1): 1340, 2018 04 09.
Artigo em Inglês | MEDLINE | ID: mdl-29632299

RESUMO

Genome-wide association studies (GWAS) have advanced our understanding of susceptibility to B-cell precursor acute lymphoblastic leukemia (BCP-ALL); however, much of the heritable risk remains unidentified. Here, we perform a GWAS and conduct a meta-analysis with two existing GWAS, totaling 2442 cases and 14,609 controls. We identify risk loci for BCP-ALL at 8q24.21 (rs28665337, P = 3.86 × 10-9, odds ratio (OR) = 1.34) and for ETV6-RUNX1 fusion-positive BCP-ALL at 2q22.3 (rs17481869, P = 3.20 × 10-8, OR = 2.14). Our findings provide further insights into genetic susceptibility to ALL and its biology.


Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Criança , Pré-Escolar , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Glicosiltransferases/genética , Antígenos HLA/genética , Humanos , Masculino , Proteínas de Fusão Oncogênica/genética , Polimorfismo de Nucleotídeo Único , Leucemia-Linfoma Linfoblástico de Células Precursoras B/imunologia , Prognóstico , Fatores de Risco
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