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1.
Br J Haematol ; 204(1): 206-220, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37726227

RESUMO

Progression to aggressive secondary acute myeloid leukaemia (sAML) poses a significant challenge in the management of myeloproliferative neoplasms (MPNs). Since the physiopathology of MPN is closely linked to the activation of interferon (IFN) signalling and that AML initiation and aggressiveness is driven by leukaemia stem cells (LSCs), we investigated these pathways in MPN to sAML progression. We found that high IFN signalling correlated with low LSC signalling in MPN and AML samples, while MPN progression and AML transformation were characterized by decreased IFN signalling and increased LSC signature. A high LSC to IFN expression ratio in MPN patients was associated with adverse clinical prognosis and higher colony forming potential. Moreover, treatment with hypomethylating agents (HMAs) activates the IFN signalling pathway in MPN cells by inducing a viral mimicry response. This response is characterized by double-stranded RNA (dsRNA) formation and MDA5/RIG-I activation. The HMA-induced IFN response leads to a reduction in LSC signature, resulting in decreased stemness. These findings reveal the frequent evasion of viral mimicry during MPN-to-sAML progression, establish the LSC-to-IFN expression ratio as a progression biomarker, and suggests that HMAs treatment can lead to haematological response in murine models by re-activating dsRNA-associated IFN signalling.


Assuntos
Leucemia Mieloide Aguda , Transtornos Mieloproliferativos , Humanos , Animais , Camundongos , Transtornos Mieloproliferativos/tratamento farmacológico , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/complicações , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Prognóstico , Biomarcadores , Interferons/uso terapêutico
2.
Nature ; 563(7732): 579-583, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30429608

RESUMO

The use of liquid biopsies for cancer detection and management is rapidly gaining prominence1. Current methods for the detection of circulating tumour DNA involve sequencing somatic mutations using cell-free DNA, but the sensitivity of these methods may be low among patients with early-stage cancer given the limited number of recurrent mutations2-5. By contrast, large-scale epigenetic alterations-which are tissue- and cancer-type specific-are not similarly constrained6 and therefore potentially have greater ability to detect and classify cancers in patients with early-stage disease. Here we develop a sensitive, immunoprecipitation-based protocol to analyse the methylome of small quantities of circulating cell-free DNA, and demonstrate the ability to detect large-scale DNA methylation changes that are enriched for tumour-specific patterns. We also demonstrate robust performance in cancer detection and classification across an extensive collection of plasma samples from several tumour types. This work sets the stage to establish biomarkers for the minimally invasive detection, interception and classification of early-stage cancers based on plasma cell-free DNA methylation patterns.


Assuntos
Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/metabolismo , Metilação de DNA , DNA de Neoplasias/sangue , DNA de Neoplasias/metabolismo , Detecção Precoce de Câncer/métodos , Neoplasias/classificação , Neoplasias/genética , Adenocarcinoma/sangue , Adenocarcinoma/genética , Animais , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/sangue , Neoplasias Colorretais/genética , Análise Mutacional de DNA , Epigênese Genética , Feminino , Xenoenxertos , Humanos , Biópsia Líquida , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Transplante de Neoplasias , Neoplasias/sangue , Especificidade de Órgãos , Neoplasias Pancreáticas/sangue , Neoplasias Pancreáticas/genética
3.
Bioinformatics ; 38(8): 2088-2095, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35150236

RESUMO

MOTIVATION: Single-molecule molecular inversion probes (smMIPs) provide an exceptionally cost-effective and modular approach for routine or large-cohort next-generation sequencing. However, processing the derived raw data to generate highly accurate variants calls remains challenging. RESULTS: We introduce SmMIP-tools, a comprehensive computational method that promotes the detection of single nucleotide variants and short insertions and deletions from smMIP-based sequencing. Our approach delivered near-perfect performance when benchmarked against a set of known mutations in controlled experiments involving DNA dilutions and outperformed other commonly used computational methods for mutation detection. Comparison against clinically approved diagnostic testing of leukaemia patients demonstrated the ability to detect both previously reported variants and a set of pathogenic mutations that did not pass detection by clinical testing. Collectively, our results indicate that increased performance can be achieved when tailoring data processing and analysis to its related technology. The feasibility of using our method in research and clinical settings to benefit from low-cost smMIP technology is demonstrated. AVAILABILITY AND IMPLEMENTATION: The source code for SmMIP-tools, its manual and additional scripts aimed to foster large-scale data processing and analysis are all available on github (https://github.com/abelson-lab/smMIP-tools). Raw sequencing data generated in this study have been submitted to the European Genome-Phenome Archive (EGA; https://ega-archive.org) and can be accessed under accession number EGAS00001005359. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Genoma , Leucemia , Humanos , Mutação , Software , Sequenciamento de Nucleotídeos em Larga Escala/métodos
4.
Blood ; 138(3): 234-245, 2021 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-34292323

RESUMO

Venetoclax, a Bcl-2 inhibitor, in combination with the hypomethylating agent azacytidine, achieves complete remission with or without count recovery in ∼70% of treatment-naive elderly patients unfit for conventional intensive chemotherapy. However, the mechanism of action of this drug combination is not fully understood. We discovered that venetoclax directly activated T cells to increase their cytotoxicity against acute myeloid leukemia (AML) in vitro and in vivo. Venetoclax enhanced T-cell effector function by increasing reactive oxygen species generation through inhibition of respiratory chain supercomplexes formation. In addition, azacytidine induced a viral mimicry response in AML cells by activating the STING/cGAS pathway, thereby rendering the AML cells more susceptible to T cell-mediated cytotoxicity. Similar findings were seen in patients treated with venetoclax, as this treatment increased reactive oxygen species generation and activated T cells. Collectively, this study presents a new immune-mediated mechanism of action for venetoclax and azacytidine in the treatment of AML and highlights a potential combination of venetoclax and adoptive cell therapy for patients with AML.


Assuntos
Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Sulfonamidas/farmacologia , Linfócitos T/efeitos dos fármacos , Adulto , Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Células Cultivadas , Humanos , Imunidade Celular/efeitos dos fármacos , Leucemia Mieloide Aguda/imunologia , Espécies Reativas de Oxigênio/imunologia , Sulfonamidas/uso terapêutico , Linfócitos T/imunologia , Células Tumorais Cultivadas
5.
Haematologica ; 108(9): 2343-2357, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37021547

RESUMO

Outcomes for patients with acute myeloid leukemia (AML) remain poor due to the inability of current therapeutic regimens to fully eradicate disease-initiating leukemia stem cells (LSC). Previous studies have demonstrated that oxidative phosphorylation (OXPHOS) is an essential process that is targetable in LSC. Sirtuin 3 (SIRT3), a mitochondrial deacetylase with a multi-faceted role in metabolic regulation, has been shown to regulate OXPHOS in cancer models; however, it has not yet been studied in the context of LSC. Thus, we sought to identify if SIRT3 is important for LSC function. Using RNAi and a SIRT3 inhibitor (YC8-02), we demonstrate that SIRT3 is a critical target for the survival of primary human LSC but is not essential for normal human hematopoietic stem and progenitor cell function. In order to elucidate the molecular mechanisms by which SIRT3 is essential in LSC we combined transcriptomic, proteomic, and lipidomic approaches, showing that SIRT3 is important for LSC function through the regulation of fatty acid oxidation (FAO) which is required to support OXPHOS and ATP production in human LSC. Further, we discovered two approaches to further sensitize LSC to SIRT3 inhibition. First, we found that LSC tolerate the toxic effects of fatty acid accumulation induced by SIRT3 inhibition by upregulating cholesterol esterification. Disruption of cholesterol homeostasis sensitizes LSC to YC8-02 and potentiates LSC death. Second, SIRT3 inhibition sensitizes LSC to the BCL-2 inhibitor venetoclax. Together, these findings establish SIRT3 as a regulator of lipid metabolism and potential therapeutic target in primitive AML cells.


Assuntos
Leucemia Mieloide Aguda , Sirtuína 3 , Humanos , Sirtuína 3/genética , Sirtuína 3/metabolismo , Sirtuína 3/farmacologia , Proteômica , Células-Tronco Neoplásicas/metabolismo , Metabolismo dos Lipídeos , Homeostase , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Ácidos Graxos/metabolismo , Ácidos Graxos/farmacologia , Ácidos Graxos/uso terapêutico , Colesterol
6.
Am J Hematol ; 97(12): 1538-1547, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36087071

RESUMO

Autologous stem cell transplantation (ASCT) remains a key therapeutic strategy for treating patients with relapsed or refractory non-Hodgkin and Hodgkin lymphoma. Clonal hematopoiesis (CH) has been proposed as a major contributor not only to the development of therapy-related myeloid neoplasms but also to inferior overall survival (OS) in patients who had undergone ASCT. Herein, we aimed to investigate the prognostic implications of CH after ASCT in a cohort of 420 lymphoma patients using ultra-deep, highly sensitive error-correction sequencing. CH was identified in the stem cell product samples of 181 patients (43.1%) and was most common in those with T-cell lymphoma (72.2%). The presence of CH was associated with a longer time to neutrophil and platelet recovery. Moreover, patients with evidence of CH had inferior 5-year OS from the time of first relapse (39.4% vs. 45.8%, p = .043) and from the time of ASCT (51.8% vs. 59.3%, p = .018). The adverse prognostic impact of CH was not due to therapy-related myeloid neoplasms, the incidence of which was low in our cohort (10-year cumulative incidence of 3.3% vs. 3.0% in those with and without CH, p = .445). In terms of specific-gene mutations, adverse OS was mostly associated with PPM1D mutations (hazard ratio (HR) 1.74, 95% confidence interval (CI) 1.13-2.67, p = .011). In summary, we found that CH is associated with an increased risk of non-lymphoma-related death after ASCT, which suggests that lymphoma survivors with CH may need intensified surveillance strategies to prevent and treat late complications.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Doença de Hodgkin , Linfoma , Segunda Neoplasia Primária , Humanos , Transplante Autólogo/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Hematopoiese Clonal , Linfoma/terapia , Linfoma/complicações , Doença de Hodgkin/complicações , Segunda Neoplasia Primária/terapia , Segunda Neoplasia Primária/genética , Transplante de Células-Tronco/efeitos adversos , Estudos Retrospectivos
7.
Nature ; 540(7633): 433-437, 2016 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-27926740

RESUMO

Refractoriness to induction chemotherapy and relapse after achievement of remission are the main obstacles to cure in acute myeloid leukaemia (AML). After standard induction chemotherapy, patients are assigned to different post-remission strategies on the basis of cytogenetic and molecular abnormalities that broadly define adverse, intermediate and favourable risk categories. However, some patients do not respond to induction therapy and another subset will eventually relapse despite the lack of adverse risk factors. There is an urgent need for better biomarkers to identify these high-risk patients before starting induction chemotherapy, to enable testing of alternative induction strategies in clinical trials. The high rate of relapse in AML has been attributed to the persistence of leukaemia stem cells (LSCs), which possess a number of stem cell properties, including quiescence, that are linked to therapy resistance. Here, to develop predictive and/or prognostic biomarkers related to stemness, we generated a list of genes that are differentially expressed between 138 LSC+ and 89 LSC- cell fractions from 78 AML patients validated by xenotransplantation. To extract the core transcriptional components of stemness relevant to clinical outcomes, we performed sparse regression analysis of LSC gene expression against survival in a large training cohort, generating a 17-gene LSC score (LSC17). The LSC17 score was highly prognostic in five independent cohorts comprising patients of diverse AML subtypes (n = 908) and contributed greatly to accurate prediction of initial therapy resistance. Patients with high LSC17 scores had poor outcomes with current treatments including allogeneic stem cell transplantation. The LSC17 score provides clinicians with a rapid and powerful tool to identify AML patients who do not benefit from standard therapy and who should be enrolled in trials evaluating novel upfront or post-remission strategies.


Assuntos
Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/terapia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Algoritmos , Animais , Estudos de Coortes , Feminino , Regulação Leucêmica da Expressão Gênica , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Camundongos , Prognóstico , Medição de Risco , Transplante de Células-Tronco , Análise de Sobrevida , Transcriptoma , Transplante Homólogo , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Br J Haematol ; 194(3): 557-567, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34131896

RESUMO

There is limited understanding of the impact of frailty on clinical outcomes in patients with myelofibrosis (MF). In this retrospective cohort study on 439 chronic phase MF patients [mean age: 68·7 ± 12 years; median follow-up: 3·4 years (IQR 0·4-8·6)] from 2004 till 2018, we used a 35-variable frailty index (FI) to categorise patient's frailty status as fit (FI < 0·2, reference), prefrail (FI 0·2-0·29) or frail (FI ≥ 0·3). The association of frailty with overall survival (OS) and cumulative JAK inhibitor (JAKi) therapy failure was measured using hazard ratio (HR, 95% CI). In multivariable analysis, prefrail (HR 1·7, 1·1-2·5) and frail patients (HR 2·9, 1·6-5·5), those with higher DIPSS score (HR 2·5, 1·6-3·9) and transfusion dependency (HR 1·9, 1·3-2·9) had shorter OS. In a subset analysis of patients on JAKi treatment (n = 222), frail patients (HR 2·5, 1·1-5·7), patients with higher DIPSS score (HR 1·7, 1·0-3·1) and transfusion dependence (HR 1·7, 1·1-2·7) had higher cumulative incidence of JAKi failure. Age, comorbidities, ECOG performance status, and MPN driver mutations did not impact outcomes. Thus, higher frailty scores are associated with worse OS and increased JAKi failure in MF, and is a superior indicator of fitness in comparison to age, comorbidities, and performance status.


Assuntos
Fragilidade/complicações , Mielofibrose Primária/complicações , Mielofibrose Primária/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Idoso , Idoso de 80 Anos ou mais , Idoso Fragilizado , Humanos , Pessoa de Meia-Idade , Mielofibrose Primária/epidemiologia , Estudos Retrospectivos , Análise de Sobrevida , Resultado do Tratamento
9.
Biol Blood Marrow Transplant ; 25(6): 1142-1151, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30625392

RESUMO

Mutational profiling has demonstrated utility in predicting the likelihood of disease progression in patients with myelofibrosis (MF). However, there is limited data regarding the prognostic utility of genetic profiling in MF patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HCT). We performed high-throughput sequencing of 585 genes on pre-transplant samples from 101 patients with MF who underwent allo-HCT and evaluated the association of mutations and clinical variables with transplantation outcomes. Overall survival (OS) at 5 years post-transplantation was 52%, and relapse-free survival (RFS) was 51.1 % for this cohort. Nonrelapse mortality (NRM) accounted for most deaths. Patient's age, donor's age, donor type, and Dynamic International Prognostic Scoring System score at diagnosis did not predict for outcomes. Mutations known to be associated with increased risk of disease progression, such as ASXL1, SRSF2, IDH1/2, EZH2, and TP53, did not impact OS or RFS. The presence of U2AF1 (P = .007) or DNMT3A (P = .034) mutations was associated with worse OS. A Mutation-Enhanced International Prognostic Scoring System 70 score was available for 80 patients (79%), and there were no differences in outcomes between patients with high risk scores and those with intermediate and low risk scores. Collectively, these data identify mutational predictors of outcome in MF patients undergoing allo-HCT. These genetic biomarkers in conjunction with clinical variables may have important utility in guiding transplantation decision making.


Assuntos
Mielofibrose Primária/terapia , Idoso , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Mielofibrose Primária/patologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
11.
Pharm Biol ; 54(11): 2652-2663, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27241623

RESUMO

CONTEXT: Eugenia dysenterica DC. (Myrtaceae) has been widely used in the folk medicine and it presents phytochemicals constituents associated to antioxidant properties. OBJECTIVE: The objective of this study was to investigate the protective effects of E. dysenterica leaf hydroalcoholic extract (EDE) in vitro and in vivo using AMJ2-C11 cells and Swiss mice exposed to hexavalent chromium [Cr(VI)], respectively. MATERIALS AND METHODS: AMJ2-C11 cells were pretreated with EDE and exposed to Cr(VI) to evaluate cytotoxicity and the pathways involved in the chemopreventive effects of the extract. Mice were daily pretreated with EDE and then exposed to Cr(VI). Survival analysis, histopathological examination and determination of Cr levels in biological tissues were carried out. RESULTS: In vitro studies showed that pretreatment of the AMJ2-C11 cells with EDE protected against the cytotoxicity and oxidative stress induced by Cr(VI). Consequently, the pretreatment with EDE reduced reactive oxygen species and apoptosis triggered by Cr(VI), probably by a marked antioxidant and chelating activities demonstrated by EDE. Regarding in vivo studies, pretreatment for 10 days with EDE increased survival of the mice exposed to Cr(VI). In addition, EDE prevented liver and kidney pathological damages, in parallel with reduction in chromium levels found in these organs and plasma. EDE also showed a marked antioxidant potential associated with the presence of polyphenols, especially flavonoids and tannins, as confirmed by HPLC-PDA. CONCLUSION: The study showed that EDE protects against Cr(VI)-induced damage in vitro and in vivo supporting further studies for the development of therapeutic products applied to prevent the damage induced by toxic metals, especially Cr(VI).


Assuntos
Cromo/toxicidade , Eugenia , Extratos Vegetais/farmacologia , Animais , Antioxidantes/farmacologia , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Células Cultivadas , Rim/efeitos dos fármacos , Rim/patologia , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Extratos Vegetais/análise , Espécies Reativas de Oxigênio/metabolismo
13.
Blood Adv ; 8(5): 1281-1294, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38170760

RESUMO

ABSTRACT: Transformation of BCR::ABL1-negative myeloproliferative neoplasms (MPN) to an accelerated or blast phase is associated with poor outcomes. The efficacy of acute myeloid leukemia (AML)-type intensive and nonintensive hypomethylating agent-based regimens is not well studied. We therefore performed a retrospective analysis of patients with MPN-AP/BP (N = 138) treated with intensive (N = 81) and nonintensive (N = 57) blast-reduction strategies. We used clinically relatable response criteria developed at the Princess Margaret Cancer Centre. The overall best response, comprising complete remission (CR), complete remission with incomplete hematologic recovery (CRi), and reversion to chronic phase MPN (cMPN), in the intensive and nonintensive groups was 77% (62 of 81) and 39% (21 of 54), respectively. Similar overall best response rates were observed in patients receiving induction with daunorubicin combined with cytarabine arabinoside (daunorubicin + ara-C) (74% [23 of 31]) or FLAG-IDA/NOVE-HiDAC (78% [39 of 50], P = .78). However, patients receiving daunorubicin + ara-C more often required second inductions (29% [9 of 31] vs 4% [2 of 50], P = .002). Most responses in the entire cohort were reversions to cMPN (55 of 83 [66%]). CR and CRi comprised 30% (25 of 83) and 4% (3 of 83) of responses, respectively. Mutations in TP53 (overall response [OR] 8.2 [95% confidence interval [CI] 2.01, 37.1], P = .004) and RAS pathway (OR 5.1 [95%CI 1.2, 23.7], P = .03) were associated with inferior treatment response for intensively treated patients, and poorer performance status (Eastern Cooperative Oncology Group) was associated with inferior treatment response in both intensively (OR 10.4 [95% CI 2.0, 78.5], P = .009) and nonintensively treated groups (OR 12 [95% CI 2.04, 230.3], P = .02). In patients with paired samples before and after therapy (N = 26), there was a significant residual mutation burden remaining irrespective of response to blast-reduction therapy.


Assuntos
Transtornos Mieloproliferativos , Humanos , Resultado do Tratamento , Estudos Retrospectivos , Transtornos Mieloproliferativos/genética , Citarabina/uso terapêutico , Daunorrubicina
14.
Blood Adv ; 8(10): 2361-2372, 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38447114

RESUMO

ABSTRACT: Advancements in genomics are transforming the clinical management of chronic myeloid leukemia (CML) toward precision medicine. The impact of somatic mutations on treatment outcomes is still under debate. We studied the association of somatic mutations in epigenetic modifier genes and activated signaling/myeloid transcription factors (AS/MTFs) with disease progression and treatment failure in patients with CML after tyrosine kinase inhibitor (TKI) therapy. A total of 394 CML samples were sequenced, including 254 samples collected at initial diagnosis and 140 samples taken during follow-up. Single-molecule molecular inversion probe (smMIP)-based next-generation sequencing (NGS) was conducted targeting recurrently mutated loci in 40 genes, with a limit of detection of 0.2%. Seventy mutations were detected in 57 diagnostic samples (22.4%), whereas 64 mutations were detected in 39 of the follow-up samples (27.9%). Carrying any mutation at initial diagnosis was associated with worse outcomes after TKI therapy, particularly in AS/MTF genes. Patients having these mutations at initial diagnosis and treated with imatinib showed higher risks of treatment failure (hazard ratio, 2.53; 95% confidence interval, 1.13-5.66; P = .0239). The adverse prognostic impact of the mutations was not clear for patients treated with second-generation TKIs. The multivariate analysis affirmed that mutations in AS/MTF genes independently serve as adverse prognostic factors for molecular response, failure-free survival, and progression risk. Additionally, there was an observable nonsignificant trend indicating a heightened risk of progression to advanced disease and worse overall survival. In conclusion, mutations in the AS/MTF genes using smMIP-based NGS can help identify patients with a potential risk of both treatment failure and progression and may help upfront TKI selection.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Mutação , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/mortalidade , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Masculino , Pessoa de Meia-Idade , Feminino , Adulto , Idoso , Transdução de Sinais , Inibidores de Proteínas Quinases/uso terapêutico , Prognóstico , Fatores de Transcrição/genética , Resultado do Tratamento , Sequenciamento de Nucleotídeos em Larga Escala , Adulto Jovem , Idoso de 80 Anos ou mais , Progressão da Doença
15.
J Immunol ; 187(11): 6002-10, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22031762

RESUMO

Signaling by innate immune receptors initiates and orchestrates the overall immune responses to infection. Macrophage receptors recognizing pathogens can be broadly grouped into surface receptors and receptors restricted to intracellular compartments, such as phagosomes and the cytoplasm. There is an expectation that ingestion and degradation of microorganisms by phagocytes contributes to activation of intracellular innate receptors, although direct demonstrations of this are rare, and many model ligands are studied in soluble form, outside of their microbial context. By comparing a wild-type strain of Staphylococcus aureus and a lysozyme-sensitive mutant, we have been able directly to address the role of degradation of live bacteria by mouse macrophages in determining the overall innate cellular inflammatory response. Our investigations revealed a biphasic response to S. aureus that consisted of an initial signal resulting from the engagement of surface TLR2, followed by a later, second wave on inflammatory gene induction. This second wave of inflammatory signaling was dependent on and correlated with the timing of bacterial degradation in phagosomes. We found that TLR2 signaling followed by TLR2/TLR9 signaling enhanced sensitivity to small numbers of bacteria. We further found that treating wild-type bacteria with the peptidoglycan synthesis-inhibiting antibiotic vancomycin made S. aureus more susceptible to degradation and resulted in increased inflammatory responses, similar to those observed for mutant degradation-sensitive bacteria.


Assuntos
Macrófagos/imunologia , Fagocitose/imunologia , Fagossomos/imunologia , Infecções Estafilocócicas/imunologia , Receptores Toll-Like/imunologia , Animais , Imunidade Inata/imunologia , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/microbiologia , Ligantes , Macrófagos/metabolismo , Macrófagos/microbiologia , Camundongos , Camundongos Knockout , Fagossomos/metabolismo , Reação em Cadeia da Polimerase , Transdução de Sinais/imunologia , Infecções Estafilocócicas/metabolismo , Staphylococcus aureus/imunologia , Receptores Toll-Like/metabolismo
16.
Nat Genet ; 55(7): 1186-1197, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37337105

RESUMO

In BCR-ABL1 lymphoblastic leukemia, treatment heterogeneity to tyrosine kinase inhibitors (TKIs), especially in the absence of kinase domain mutations in BCR-ABL1, is poorly understood. Through deep molecular profiling, we uncovered three transcriptomic subtypes of BCR-ABL1 lymphoblastic leukemia, each representing a maturation arrest at a stage of B-cell progenitor differentiation. An earlier arrest was associated with lineage promiscuity, treatment refractoriness and poor patient outcomes. A later arrest was associated with lineage fidelity, durable leukemia remissions and improved patient outcomes. Each maturation arrest was marked by specific genomic events that control different transition points in B-cell development. Interestingly, these events were absent in BCR-ABL1+ preleukemic stem cells isolated from patients regardless of subtype, which supports that transcriptomic phenotypes are determined downstream of the leukemia-initialing event. Overall, our data indicate that treatment response and TKI efficacy are unexpected outcomes of the differentiation stage at which this leukemia transforms.


Assuntos
Proteínas de Fusão bcr-abl , Leucemia-Linfoma Linfoblástico de Células Precursoras , Humanos , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Transcriptoma/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Perfilação da Expressão Gênica , Diferenciação Celular/genética , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico
17.
Leukemia ; 37(4): 751-764, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36720973

RESUMO

Acute myeloid leukemia (AML) is a heterogeneous, aggressive malignancy with dismal prognosis and with limited availability of targeted therapies. Epigenetic deregulation contributes to AML pathogenesis. KDM6 proteins are histone-3-lysine-27-demethylases that play context-dependent roles in AML. We inform that KDM6-demethylase function critically regulates DNA-damage-repair-(DDR) gene expression in AML. Mechanistically, KDM6 expression is regulated by genotoxic stress, with deficiency of KDM6A-(UTX) and KDM6B-(JMJD3) impairing DDR transcriptional activation and compromising repair potential. Acquired KDM6A loss-of-function mutations are implicated in chemoresistance, although a significant percentage of relapsed-AML has upregulated KDM6A. Olaparib treatment reduced engraftment of KDM6A-mutant-AML-patient-derived xenografts, highlighting synthetic lethality using Poly-(ADP-ribose)-polymerase-(PARP)-inhibition. Crucially, a higher KDM6A expression is correlated with venetoclax tolerance. Loss of KDM6A increased mitochondrial activity, BCL2 expression, and sensitized AML cells to venetoclax. Additionally, BCL2A1 associates with venetoclax resistance, and KDM6A loss was accompanied with a downregulated BCL2A1. Corroborating these results, dual targeting of PARP and BCL2 was superior to PARP or BCL2 inhibitor monotherapy in inducing AML apoptosis, and primary AML cells carrying KDM6A-domain mutations were even more sensitive to the combination. Together, our study illustrates a mechanistic rationale in support of a novel combination therapy for AML based on subtype-heterogeneity, and establishes KDM6A as a molecular regulator for determining therapeutic efficacy.


Assuntos
Leucemia Mieloide Aguda , Inibidores de Poli(ADP-Ribose) Polimerases , Humanos , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histona Desmetilases com o Domínio Jumonji , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Inibidores de Poli(ADP-Ribose) Polimerases/uso terapêutico , Proteínas Proto-Oncogênicas c-bcl-2/genética
18.
JCI Insight ; 7(20)2022 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-36125881

RESUMO

Cancer cells release large quantities of cell-free DNA (cfDNA) into the surrounding tissue and circulation. As cfDNA is a common source of biomarkers for liquid biopsy and has been implicated as a functional mediator for intercellular communication, fundamental characterization of cfDNA topology has widespread biological and clinical ramifications. Whether the topology of cfDNA is such that it exists predominantly in membrane-bound extracellular vesicles (EVs) or in nonvesicular DNA-protein complexes remains poorly understood. Here, we employed a DNA-targeted approach to comprehensively assess total cfDNA topology in cancer. Using preclinical models and patient samples, we demonstrate that nuclear cfDNA is predominantly associated with nucleosomal particles and not EVs, while a substantial subset of mitochondrial cfDNA is membrane protected and disproportionately derived from nontumor cells. In addition, discrimination between membrane-protected and accessible mitochondrial cfDNA added diagnostic and prognostic value in a cohort of head and neck cancer patients. Our results support a revised model for cfDNA topology in cancer. Due to its abundance, nuclear cfDNA within nucleosomal particles is the most compelling liquid biopsy substrate, while EV-bound and accessible mitochondrial cfDNA represent distinct reservoirs of potential cancer biomarkers whose structural conformations may also influence their extracellular stability and propensity for uptake by recipient cells.


Assuntos
Ácidos Nucleicos Livres , Neoplasias , Humanos , Biópsia Líquida/métodos , Neoplasias/genética , Biomarcadores Tumorais , DNA
19.
Leukemia ; 36(11): 2690-2704, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36131042

RESUMO

Many cancers are organized as cellular hierarchies sustained by cancer stem cells (CSC), whose eradication is crucial for achieving long-term remission. Difficulties to isolate and undertake in vitro and in vivo experimental studies of rare CSC under conditions that preserve their original properties currently constitute a bottleneck for identifying molecular mechanisms involving coding and non-coding genomic regions that govern stemness. We focussed on acute myeloid leukemia (AML) as a paradigm of the CSC model and developed a patient-derived system termed OCI-AML22 that recapitulates the cellular hierarchy driven by leukemia stem cells (LSC). Through classical flow sorting and functional analyses, we established that a single phenotypic population is highly enriched for LSC. The LSC fraction can be easily isolated and serially expanded in culture or in xenografts while faithfully recapitulating functional, transcriptional and epigenetic features of primary LSCs. A novel non-coding regulatory element was identified with a new computational approach using functionally validated primary AML LSC fractions and its role in LSC stemness validated through efficient CRISPR editing using methods optimized for OCI-AML22 LSC. Collectively, OCI-AML22 constitutes a valuable resource to uncover mechanisms governing CSC driven malignancies.


Assuntos
Leucemia Mieloide Aguda , Células-Tronco Neoplásicas , Humanos , Células-Tronco Neoplásicas/patologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia
20.
J Environ Chem Eng ; 10(5): 108298, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35873721

RESUMO

Since 2020, developed countries have rapidly shared both publicly and academically relevant wastewater surveillance information. Data on SARS-CoV-2 circulation is pivotal for guiding public health policies and improving the COVID-19 pandemic response. Conversely, low- and middle-income countries, such as Latin America and the Caribbean, showed timid activities in the Wastewater-Based Epidemiology (WBE) context. In these countries, isolated groups perform viral wastewater monitoring, and the data are unevenly shared or accessible to health agencies and the scientific community. This manuscript aims to highlight the relevance of a multiparty effort involving research, public health, and governmental agencies to support usage of WBE methodology to its full potential during the COVID-19 pandemic as part of a joint One Health surveillance approach. Thus, in this study, we explored the results obtained from wastewater surveillance in different regions of Brazil as a part of the COVID-19 Wastewater Monitoring Network ANA (National Water Agency), MCTI (Ministry of Science, Technology, and Innovations) and MS (Ministry of Health). Over the epidemiological weeks of 2021 and early 2022, viral RNA concentrations in wastewater followed epidemiological trends and variations. The highest viral loads in wastewater samples were detected during the second Brazilian wave of COVID-19. Corroborating international reports, our experience demonstrated usefulness of the WBE approach in viral surveillance. Wastewater surveillance allows hotspot identification, and therefore, early public health interventions. In addition, this methodology allows tracking of asymptomatic and oligosymptomatic individuals, who are generally underreported, especially in emerging countries with limited clinical testing capacity. Therefore, WBE undoubtedly contributes to improving public health responses in the context of this pandemic, as well as other sanitary emergencies.

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