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1.
Leukemia ; 34(1): 63-74, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31300747

RESUMO

Acute myeloid leukemias (AML) with mutations in the NPM1 gene (NPM1c+) represent a large AML subgroup with varying response to conventional treatment, highlighting the need to develop targeted therapeutic strategies for this disease. We screened a library of clinical drugs on a cohort of primary human AML specimens and identified the BCL2 inhibitor ABT-199 as a selective agent against NPM1c+ AML. Mutational analysis of ABT-199-sensitive and -resistant specimens identified mutations in NPM1, RAD21, and IDH1/IDH2 as predictors of ABT-199 sensitivity. Comparative transcriptome analysis further uncovered BCL2A1 as a potential mediator of ABT-199 resistance in AML. In line with our observation that RAD21 mutation confers sensitivity to ABT-199, we provide functional evidence that reducing RAD21 levels can sensitize AML cells to BCL2 inhibition. Moreover, we demonstrate that ABT-199 is able to produce selective anti-AML activity in vivo toward AML with mutations associated with compound sensitivity in PDX models. Overall, this study delineates the contribution of several genetic events to the response to ABT-199 and provides a rationale for the development of targeted therapies for NPM1c+ AML.

2.
Lancet Haematol ; 7(2): e134-e145, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31704264

RESUMO

BACKGROUND: Benefits of cord blood transplantation include low rates of relapse and chronic graft-versus-host disease (GVHD). However, the use of cord blood is rapidly declining because of the high incidence of infections, severe acute GVHD, and transplant-related mortality. UM171, a haematopoietic stem cell self-renewal agonist, has been shown to expand cord blood stem cells and enhance multilineage blood cell reconstitution in mice. We aimed to investigate the safety and feasibility of single UM171-expanded cord blood transplantation in patients with haematological malignancies who do not have a suitable HLA-matched donor. METHODS: This single-arm, open-label, phase 1-2 safety and feasibility study was done at two hospitals in Canada. The study had two parts. In part 1, patients received two cord blood units (one expanded with UM171 and one unmanipulated cord blood) until UM171-expanded cord blood demonstrated engraftment. Once engraftment was documented we initiated part 2, reported here, in which patients received a single UM171-expanded cord blood unit with a dose de-escalation design to determine the minimal cord blood unit cell dose that achieved prompt engraftment. Eligible patients were aged 3-64 years, weighed 12 kg or more, had a haematological malignancy with an indication for allogeneic hematopoietic stem cell transplant and did not have a suitable HLA-matched donor, and a had a Karnofsky performance status score of 70% or more. Five clinical sites were planned to participate in the study; however, only two study sites opened, both of which only treated adult patients, thus no paediatric patients (aged <18 years) were recruited. Patients aged younger than 50 years without comorbidities received a myeloablative conditioning regimen (cyclophosphamide 120 mg/kg, fludarabine 75 mg/m2, and 12 Gy total body irradiation) and patients aged older than 50 years and those with comorbidities received a less myeloablative conditioning regimen (cyclophosphamide 50 mg/kg, thiotepa 10 mg/kg, fludarabine 150 mg/m2, and 4 Gy total body irradiation). Patients were infused with the 7-day UM171-expanded CD34-positive cells and the lymphocyte-containing CD34-negative fraction. The primary endpoints were feasibility of UM171 expansion, safety of the transplant, kinetics of hematopoietic reconstitution (time to neutrophil and platelet engraftment) of UM171-expanded cord blood, and minimal pre-expansion cord blood unit cell dose that achieved prompt engraftment. We analysed feasibility in all enrolled patients and all other primary outcomes were analysed per protocol, in all patients who received single UM171-expanded cord blood transplantation. This trial has been completed and was registered with ClinicalTrials.gov, NCT02668315. FINDINGS: Between Feb 17, 2016, and Nov 11, 2018, we enrolled 27 patients, four of whom received two cord blood units for safety purposes in part 1 of the study. 23 patients were subsequently enrolled in part 2 to receive a single UM171-expanded cord blood transplant and 22 patients received a single UM171-expanded cord blood transplantation. At data cutoff (Dec 31, 2018), median follow-up was 18 months (IQR 12-22). The minimal cord blood unit cell dose at thaw that achieved prompt engraftment as a single cord transplant after UM171 expansion was 0·52 × 105 CD34-positive cells. We successfully expanded 26 (96%) of 27 cord blood units with UM171. Among the 22 patients who received single UM171-expanded cord blood transplantation, median time to engraftment of 100 neutrophils per µL was 9·5 days (IQR 8-12), median time to engraftment of 500 neutrophils per µL was 18 days (12·5-20·0), and no graft failure occurred. Median time to platelet recovery was 42 days (IQR 35-47). The most common non-haematological adverse events were grade 3 febrile neutropenia (16 [73%] of 22 patients) and bacteraemia (nine [41%]). No unexpected adverse events were observed. One (5%) of 22 patients died due to treatment-related diffuse alveolar haemorrhage. INTERPRETATION: Our preliminary findings suggest that UM171 cord blood stem cell expansion is feasible, safe, and allows for the use of small single cords without compromising engraftment. UM171-expanded cord blood might have the potential to overcome the disadvantages of other cord blood transplants while maintaining the benefits of low risk of chronic GVHD and relapse, and warrants further investigation in randomised trials. FUNDING: Canadian Institutes of Health Research, Canadian Cancer Society and Stem Cell Network.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Indóis/farmacologia , Pirimidinas/farmacologia , Adolescente , Adulto , Autorrenovação Celular/efeitos dos fármacos , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/transplante , Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Intervalo Livre de Doença , Estudos de Viabilidade , Neutropenia Febril/etiologia , Feminino , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/etiologia , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Células-Tronco Hematopoéticas/citologia , Humanos , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Resultado do Tratamento , Adulto Jovem
3.
Bioinformatics ; 35(14): i464-i473, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-31510684

RESUMO

MOTIVATION: The efficacy of a chemical compound is often tested through dose-response experiments from which efficacy metrics, such as the IC50, can be derived. The Marquardt-Levenberg algorithm (non-linear regression) is commonly used to compute estimations for these metrics. The analysis are however limited and can lead to biased conclusions. The approach does not evaluate the certainty (or uncertainty) of the estimates nor does it allow for the statistical comparison of two datasets. To compensate for these shortcomings, intuition plays an important role in the interpretation of results and the formulations of conclusions. We here propose a Bayesian inference methodology for the analysis and comparison of dose-response experiments. RESULTS: Our results well demonstrate the informativeness gain of our Bayesian approach in comparison to the commonly used Marquardt-Levenberg algorithm. It is capable to characterize the noise of dataset while inferring probable values distributions for the efficacy metrics. It can also evaluate the difference between the metrics of two datasets and compute the probability that one value is greater than the other. The conclusions that can be drawn from such analyzes are more precise. AVAILABILITY AND IMPLEMENTATION: We implemented a simple web interface that allows the users to analyze a single dose-response dataset, as well as to statistically compare the metrics of two datasets.

4.
ACS Omega ; 4(6): 10056-10069, 2019 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-31460098

RESUMO

The worldwide use of the broad-spectrum antimicrobial trimethoprim (TMP) has induced the rise of TMP-resistant microorganisms. In addition to resistance-causing mutations of the microbial chromosomal dihydrofolate reductase (Dfr), the evolutionarily and structurally unrelated type II Dfrs (DfrBs) have been identified in TMP-resistant microorganisms. DfrBs are intrinsically TMP-resistant and allow bacterial proliferation when the microbial chromosomal Dfr is TMP-inhibited, making these enzymes important targets for inhibitor development. Furthermore, DfrBs occur in multiresistance plasmids, potentially accelerating their dissemination. We previously reported symmetrical bisbenzimidazoles that are the first selective inhibitors of the only well-characterized DfrB, DfrB1. Here, their diversification provides a new series of inhibitors (K i = 1.7-12.0 µM). Our results reveal two prominent features: terminal carboxylates and inhibitor length allow the establishment of essential interactions with DfrB1. Two crystal structures demonstrate the simultaneous binding of two inhibitor molecules in the symmetrical active site. Observations of those dimeric inhibitors inspired the design of monomeric analogues, binding in a single copy yet offering similar inhibition potency (K i = 1.1 and 7.4 µM). Inhibition of a second member of the DfrB family, DfrB4, suggests the generality of these inhibitors. These results provide key insights into inhibition of the highly TMP-resistant DfrBs, opening avenues to downstream development of antibiotics for combatting this emergent source of resistance.

5.
Cancer Cell ; 36(1): 84-99.e8, 2019 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-31287994

RESUMO

To identify therapeutic targets in acute myeloid leukemia (AML), we chemically interrogated 200 sequenced primary specimens. Mubritinib, a known ERBB2 inhibitor, elicited strong anti-leukemic effects in vitro and in vivo. In the context of AML, mubritinib functions through ubiquinone-dependent inhibition of electron transport chain (ETC) complex I activity. Resistance to mubritinib characterized normal CD34+ hematopoietic cells and chemotherapy-sensitive AMLs, which displayed transcriptomic hallmarks of hypoxia. Conversely, sensitivity correlated with mitochondrial function-related gene expression levels and characterized a large subset of chemotherapy-resistant AMLs with oxidative phosphorylation (OXPHOS) hyperactivity. Altogether, our work thus identifies an ETC complex I inhibitor and reveals the genetic landscape of OXPHOS dependency in AML.

6.
J Med Chem ; 62(16): 7400-7416, 2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31246024

RESUMO

In an effort to identify novel antithrombotics, we have investigated protease-activated receptor 4 (PAR4) antagonism by developing and evaluating a tool compound, UDM-001651, in a monkey thrombosis model. Beginning with a high-throughput screening hit, we identified an imidazothiadiazole-based PAR4 antagonist chemotype. Detailed structure-activity relationship studies enabled optimization to a potent, selective, and orally bioavailable PAR4 antagonist, UDM-001651. UDM-001651 was evaluated in a monkey thrombosis model and shown to have robust antithrombotic efficacy and no prolongation of kidney bleeding time. This combination of excellent efficacy and safety margin strongly validates PAR4 antagonism as a promising antithrombotic mechanism.

7.
Sci Rep ; 9(1): 5504, 2019 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-30940883

RESUMO

Caspase-6 is a cysteine protease that plays essential roles in programmed cell death, axonal degeneration, and development. The excess neuronal activity of Caspase-6 is associated with Alzheimer disease neuropathology and age-dependent cognitive impairment. Caspase-6 inhibition is a promising strategy to stop early stage neurodegenerative events, yet finding potent and selective Caspase-6 inhibitors has been a challenging task due to the overlapping structural and functional similarities between caspase family members. Here, we investigated how four rare non-synonymous missense single-nucleotide polymorphisms (SNPs), resulting in amino acid substitutions outside human Caspase-6 active site, affect enzyme structure and catalytic efficiency. Three investigated SNPs were found to align with a putative allosteric pocket with low sequence conservation among human caspases. Virtual screening of 57,700 compounds against the putative Caspase-6 allosteric pocket, followed by in vitro testing of the best virtual hits in recombinant human Caspase-6 activity assays identified novel allosteric Caspase-6 inhibitors with IC50 and Ki values ranging from ~2 to 13 µM. This report may pave the way towards the development and optimisation of novel small molecule allosteric Caspase-6 inhibitors and illustrates that functional characterisation of rare natural variants holds promise for the identification of allosteric sites on other therapeutic targets in drug discovery.

8.
Org Lett ; 21(7): 2265-2268, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30883143

RESUMO

The synthesis of several 1,1-disubstituted trifluoromethyl-cyclopropanes (TFCPs), known as tert-butyl bioisosteres, has been achieved from the reaction between trifluoromethylalkenes and unstabilized sulfonium ylides in yields of ≤97%. This method offers practical access to this cyclopropyl moiety of pharmacological interest, employing a commercially available reagent at low temperatures. The synthesis of cyclopropanes bearing other electron-withdrawing groups as well as trisubstituted TFCPs was also accomplished.

9.
Blood Adv ; 3(4): 552-563, 2019 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-30782614

RESUMO

Patients diagnosed with acute myeloid leukemia with complex karyotype (CK AML) have an adverse prognosis using current therapies, especially when accompanied by TP53 alterations. We hereby report the RNA-sequencing analysis of the 68 CK AML samples included in the Leucegene 415 patient cohort. We confirm the frequent occurrence of TP53 alterations in this subgroup and further characterize the allele expression profile and transcript alterations of this gene. We also document that the RAS pathway (N/KRAS, NF1, PTPN11, BRAF) is frequently altered in this disease. Targeted chemical interrogation of genetically characterized primary CK AML samples identifies polo-like kinase 1 (PLK1) inhibitors as the most selective agents for this disease subgroup. TP53 status did not alter sensitivity to PLK1 inhibitors. Interestingly, CK AML specimens display a G2/M transcriptomic signature that includes higher expression levels of PLK1 and correlates with PLK1 inhibition sensitivity. Together, our results highlight vulnerability in CK AML. In line with these in vitro data, volasertib shows a strong anti-AML activity in xenotransplantation mouse models of human adverse AML. Considering that PLK1 inhibitors are currently being investigated clinically in AML and myelodysplastic syndromes, our results provide a new rationale for PLK1-directed therapy in patients with adverse cytogenetic AML.

10.
Neurocrit Care ; 30(2): 440-448, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30267280

RESUMO

BACKGROUND: Early diagnostic orientation for differentiating pneumonia from pneumonitis at the early stage after aspiration would be valuable to avoid unnecessary antibiotic therapy. We assessed the accuracy of procalcitonin (PCT) in diagnosing aspiration pneumonia (AP) in intensive care unit (ICU) patients requiring mechanical ventilation after out-of-hospital coma. METHODS: Prospective observational 2-year cohort study in a medical-surgical ICU. PCT, C-reactive protein (CRP) and white blood cell count (WBC) were measured at admission (H0) and 6 h (H), H12, H24, H48, H96, and H120 after inclusion. Lower respiratory tract microbiological investigations performed routinely in patients with aspiration syndrome were the reference standard for diagnosing AP. Performance of PCT, CRP, and WBC up to H48 in diagnosing AP was compared based on the areas under the ROC curves (AUC) and likelihood ratios (LR+ and LR-) computed for the best cutoff values. RESULTS: Of 103 patients with coma, 45 (44%) had AP. Repeated PCT assays demonstrated a significant increase in patients with AP versus without AP from H0 to H120. Among the three biomarkers, PCT showed the earliest change. ROC-AUC values were poor for all three biomarkers. Best ROC-AUC values for diagnosing AP were for CRP at H24 [0.73 (95%CI 0.61-0.84)] and PCT at H48 [0.73 (95%CI 0.61-0.84)]. LR+ was best for PCT at H24 (3.5) and LR- for CRP and WBC at H24 (0.4 and 0.4, respectively). CONCLUSIONS: Early and repeated assays of PCT, CRP, and WBC demonstrated significant increases in all three biomarkers in patients with versus without AP. All three biomarkers had poor diagnostic performance for ruling out AP. Whereas PCT had the fastest kinetics, PCT assays within 48 h after ICU admission do not help to diagnose AP in ICU patients with coma.


Assuntos
Coma/terapia , Cuidados Críticos/normas , Técnicas de Diagnóstico Neurológico/normas , Pneumonia Aspirativa/sangue , Pneumonia Aspirativa/diagnóstico , Pró-Calcitonina/sangue , Respiração Artificial/efeitos adversos , Adulto , Biomarcadores/sangue , Coma/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pneumonia Aspirativa/etiologia , Estudos Prospectivos , Sensibilidade e Especificidade
11.
Leukemia ; 32(6): 1349-1357, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29550835

RESUMO

Acute promyelocytic leukemia (APL) is a medical emergency because of associated lethal early bleeding, a condition preventable by prompt diagnosis and therapeutic intervention. The mechanisms underlying the hemostatic anomalies of APL are not completely elucidated. RNA-sequencing-based characterization of APL (n = 30) was performed and compared to that of other acute myeloid leukemia (n = 400) samples and normal promyelocytes. Perturbations in the transcriptome of coagulation and fibrinolysis-related genes in APL extend beyond known culprits and now include Thrombin, Factor X and Urokinase Receptor. Most intriguingly, the Podoplanin (PDPN) gene, involved in platelet aggregation, is aberrantly expressed in APL promyelocytes and is the most distinctive transcript for this disease. Using an antibody panel optimized for AML diagnosis by flow cytometry, we also found that PDPN was the most specific surface marker for APL, and that all-trans retinoic acid therapy rapidly decreases its expression. Functional studies showed that engineered overexpression of this gene in human leukemic cells causes aberrant platelet binding, activation and aggregation. PDPN-expressing primary APL cells, but not PDPN-negative primary leukemias, specifically induce platelet binding, activation and aggregation. Finally, PDPN expression on leukemia cells in a xenograft model was associated with thrombocytopenia and prolonged bleeding time in vivo. Together our results suggest that PDPN may contribute to the hemostatic perturbations found in APL.


Assuntos
Hemorragia/etiologia , Leucemia Promielocítica Aguda/complicações , Glicoproteínas de Membrana/fisiologia , Transcriptoma , Adulto , Idoso , Animais , Feminino , Citometria de Fluxo , Humanos , Leucemia Promielocítica Aguda/genética , Masculino , Glicoproteínas de Membrana/genética , Camundongos , Pessoa de Meia-Idade , Agregação Plaquetária , Trombocitopenia/etiologia , Tretinoína/farmacologia
12.
Clin Cancer Res ; 23(22): 6969-6981, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-28855357

RESUMO

Purpose:RUNX1-mutated (RUNX1mut) acute myeloid leukemia (AML) is associated with adverse outcome, highlighting the urgent need for a better genetic characterization of this AML subgroup and for the design of efficient therapeutic strategies for this disease. Toward this goal, we further dissected the mutational spectrum and gene expression profile of RUNX1mut AML and correlated these results to drug sensitivity to identify novel compounds targeting this AML subgroup.Experimental Design: RNA-sequencing of 47 RUNX1mut primary AML specimens was performed and sequencing results were compared to those of RUNX1 wild-type samples. Chemical screens were also conducted using RUNX1mut specimens to identify compounds selectively affecting the viability of RUNX1mut AML.Results: We show that samples with no remaining RUNX1 wild-type allele are clinically and genetically distinct and display a more homogeneous gene expression profile. Chemical screening revealed that most RUNX1mut specimens are sensitive to glucocorticoids (GCs) and we confirmed that GCs inhibit AML cell proliferation through their interaction with the glucocorticoid receptor (GR). We observed that specimens harboring RUNX1 mutations expected to result in low residual RUNX1 activity are most sensitive to GCs, and that coassociating mutations as well as GR levels contribute to GC sensitivity. Accordingly, acquired glucocorticoid sensitivity was achieved by negatively regulating RUNX1 expression in human AML cells.Conclusions: Our findings show the profound impact of RUNX1 allele dosage on gene expression profile and glucocorticoid sensitivity in AML, thereby opening opportunities for preclinical testing which may lead to drug repurposing and improved disease characterization. Clin Cancer Res; 23(22); 6969-81. ©2017 AACR.


Assuntos
Alelos , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Resistencia a Medicamentos Antineoplásicos/genética , Dosagem de Genes , Glucocorticoides/farmacologia , Leucemia Mieloide Aguda/genética , Mutação , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Feminino , Regulação Leucêmica da Expressão Gênica , Inativação Gênica , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade
13.
Sci Transl Med ; 9(371)2017 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-28053157

RESUMO

Antiplatelet agents are proven efficacious treatments for cardiovascular and cerebrovascular diseases. However, the existing drugs are compromised by unwanted and sometimes life-threatening bleeding that limits drug usage or dosage. There is a substantial unmet medical need for an antiplatelet drug with strong efficacy and low bleeding risk. Thrombin is a potent platelet agonist that directly induces platelet activation via the G protein (heterotrimeric guanine nucleotide-binding protein)-coupled protease-activated receptors PAR1 and PAR4. A PAR1 antagonist is approved for clinical use, but its use is limited by a substantial bleeding risk. Conversely, the potential of PAR4 as an antiplatelet target has not been well characterized. Using anti-PAR4 antibodies, we demonstrated a low bleeding risk and an effective antithrombotic profile with PAR4 inhibition in guinea pigs. Subsequently, high-throughput screening and an extensive medicinal chemistry effort resulted in the discovery of BMS-986120, an orally active, selective, and reversible PAR4 antagonist. In a cynomolgus monkey arterial thrombosis model, BMS-986120 demonstrated potent and highly efficacious antithrombotic activity. BMS-986120 also exhibited a low bleeding liability and a markedly wider therapeutic window compared to the standard antiplatelet agent clopidogrel tested in the same nonhuman primate model. These preclinical findings define the biological role of PAR4 in mediating platelet aggregation. In addition, they indicate that targeting PAR4 is an attractive antiplatelet strategy with the potential to treat patients at a high risk of atherothrombosis with superior safety compared with the current standard of care.


Assuntos
Anticorpos/uso terapêutico , Fibrinolíticos/uso terapêutico , Hemorragia/tratamento farmacológico , Inibidores da Agregação de Plaquetas/uso terapêutico , Receptores de Trombina/antagonistas & inibidores , Administração Oral , Animais , Plaquetas/metabolismo , Cobaias , Células HEK293 , Humanos , Concentração Inibidora 50 , Macaca fascicularis , Masculino , Domínios Proteicos , Receptor PAR-1/metabolismo , Acidente Vascular Cerebral/tratamento farmacológico , Trombina/química , Trombose , Resultado do Tratamento
14.
Sci Rep ; 5: 37581, 2016 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-27874094

RESUMO

Polo-like kinase 1 (Plk1) plays several roles in cell division and it is a recognized cancer drug target. Plk1 levels are elevated in cancer and several types of cancer cells are hypersensitive to Plk1 inhibition. Small molecule inhibitors of the kinase domain (KD) of Plk1 have been developed. Their selectivity is limited, which likely contributes to their toxicity. Polo-like kinases are characterized by a Polo-Box Domain (PBD), which mediates interactions with phosphorylation substrates or regulators. Inhibition of the PBD could allow better selectivity or result in different effects than inhibition of the KD. In vitro screens have been used to identify PBD inhibitors with mixed results. We developed the first cell-based assay to screen for PBD inhibitors, using Bioluminescence Resonance Energy Transfer (BRET). We screened through 112 983 compounds and characterized hits in secondary biochemical and biological assays. Subsequent Structure-Activity Relationship (SAR) analysis on our most promising hit revealed that it requires an alkylating function for its activity. In addition, we show that the previously reported PBD inhibitors thymoquinone and Poloxin are also alkylating agents. Our cell-based assay is a promising tool for the identification of new PBD inhibitors with more drug-like profiles using larger and more diverse chemical libraries.


Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Alquilantes/química , Alquilantes/farmacologia , Benzoatos/química , Benzoatos/farmacologia , Benzoquinonas/química , Benzoquinonas/farmacologia , Técnicas de Transferência de Energia por Ressonância de Bioluminescência , Células HEK293 , Ensaios de Triagem em Larga Escala , Humanos , Domínios e Motivos de Interação entre Proteínas , Inibidores de Proteínas Quinases/química , Quinonas/química , Quinonas/farmacologia , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade
15.
J Clin Invest ; 126(12): 4569-4584, 2016 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-27797342

RESUMO

Current chemotherapies for T cell acute lymphoblastic leukemia (T-ALL) efficiently reduce tumor mass. Nonetheless, disease relapse attributed to survival of preleukemic stem cells (pre-LSCs) is associated with poor prognosis. Herein, we provide direct evidence that pre-LSCs are much less chemosensitive to existing chemotherapy drugs than leukemic blasts because of a distinctive lower proliferative state. Improving therapies for T-ALL requires the development of strategies to target pre-LSCs that are absolutely dependent on their microenvironment. Therefore, we designed a robust protocol for high-throughput screening of compounds that target primary pre-LSCs maintained in a niche-like environment, on stromal cells that were engineered for optimal NOTCH1 activation. The multiparametric readout takes into account the intrinsic complexity of primary cells in order to specifically monitor pre-LSCs, which were induced here by the SCL/TAL1 and LMO1 oncogenes. We screened a targeted library of compounds and determined that the estrogen derivative 2-methoxyestradiol (2-ME2) disrupted both cell-autonomous and non-cell-autonomous pathways. Specifically, 2-ME2 abrogated pre-LSC viability and self-renewal activity in vivo by inhibiting translation of MYC, a downstream effector of NOTCH1, and preventing SCL/TAL1 activity. In contrast, normal hematopoietic stem/progenitor cells remained functional. These results illustrate how recapitulating tissue-like properties of primary cells in high-throughput screening is a promising avenue for innovation in cancer chemotherapy.


Assuntos
Estradiol/análogos & derivados , Células-Tronco Neoplásicas/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/metabolismo , Microambiente Tumoral/efeitos dos fármacos , 2-Metoxiestradiol , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Estradiol/farmacologia , Humanos , Células Jurkat , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/metabolismo , Camundongos , Células-Tronco Neoplásicas/patologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Receptor Notch1/genética , Receptor Notch1/metabolismo , Proteína 1 de Leucemia Linfocítica Aguda de Células T , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Microambiente Tumoral/genética , Ensaio Tumoral de Célula-Tronco , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Blood ; 127(24): 3054-61, 2016 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-27034432

RESUMO

In this study, we analyzed RNA-sequencing data of 14 samples characterized by biallelic CEBPA (CEBPA(bi)) mutations included in the Leucegene collection of 415 primary acute myeloid leukemia (AML) specimens, and describe for the first time high frequency recurrent mutations in the granulocyte colony-stimulating factor receptor gene CSF3R, which signals through JAK-STAT proteins. Chemical interrogation of these primary human specimens revealed a uniform and specific sensitivity to all JAK inhibitors tested irrespective of their CSF3R mutation status, indicating a general sensitization of JAK-STAT signaling in this leukemia subset. Altogether, these results identified the co-occurrence of mutations in CSF3R and CEBPA in a well-defined AML subset, which uniformly responds to JAK inhibitors and paves the way to personalized clinical trials for this disease.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/genética , Resistencia a Medicamentos Antineoplásicos/genética , Janus Quinases/antagonistas & inibidores , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/genética , Inibidores de Proteínas Quinases/uso terapêutico , Receptores de Fator Estimulador de Colônias/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Análise Mutacional de DNA/métodos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Perfilação da Expressão Gênica , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Leucemia Mieloide Aguda/classificação , Leucemia Mieloide Aguda/patologia , Masculino , Pessoa de Meia-Idade , Mutação , Medicina de Precisão , Transcriptoma , Células Tumorais Cultivadas , Adulto Jovem
17.
Nat Genet ; 47(9): 1030-7, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26237430

RESUMO

Using next-generation sequencing of primary acute myeloid leukemia (AML) specimens, we identified to our knowledge the first unifying genetic network common to the two subgroups of KMT2A (MLL)-rearranged leukemia, namely having MLL fusions or partial tandem duplications. Within this network, we experimentally confirmed upregulation of the gene with the most subtype-specific increase in expression, LOC100289656, and identified cryptic MLL fusions, including a new MLL-ENAH fusion. We also identified a subset of MLL fusion specimens carrying mutations in SPI1 accompanied by inactivation of its transcriptional network, as well as frequent RAS pathway mutations, which sensitized the leukemias to synthetic lethal interactions between MEK and receptor tyrosine kinase inhibitors. This transcriptomics-based characterization and chemical interrogation of human MLL-rearranged AML was a valuable approach for identifying complementary features that define this disease.


Assuntos
Regulação Leucêmica da Expressão Gênica , Histona-Lisina N-Metiltransferase/genética , Leucemia Mieloide Aguda/genética , Proteína de Leucina Linfoide-Mieloide/genética , Transcriptoma , Animais , Antineoplásicos/farmacologia , Estudos de Casos e Controles , Resistencia a Medicamentos Antineoplásicos , Redes Reguladoras de Genes , Humanos , Leucemia Mieloide Aguda/metabolismo , Camundongos Endogâmicos NOD , Camundongos SCID , Mutação , Transplante de Neoplasias , Proteínas de Fusão Oncogênica/genética , Translocação Genética , Proteínas ras/genética
18.
Nat Struct Mol Biol ; 22(1): 37-43, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25437913

RESUMO

Reported RAF kinase domain structures adopt a side-to-side dimer configuration reflective of an 'on' state that underpins an allosteric mechanism of regulation. Atomic details of the monomer 'off' state have been elusive. Reinspection of the BRAF kinase domain structures revealed that sulfonamide inhibitors induce features of an off state, primarily a laterally displaced helix αC stabilized by the activation segment helix 1 (AS-H1). These features correlated with the ability of sulfonamides to disrupt human BRAF homodimers in cells, in vitro and in crystals yielding a structure of BRAF in a monomer state. The crystal structure revealed exaggerated, nonproductive positions of helix αC and AS-H1, the latter of which is the target of potent BRAF oncogenic mutations. Together, this work provides formal proof of an allosteric link between the RAF dimer interface, the activation segment and the catalytic infrastructure.


Assuntos
Regulação Alostérica , Proteínas Proto-Oncogênicas B-raf/química , Proteínas Proto-Oncogênicas B-raf/metabolismo , Humanos , Ligação Proteica , Conformação Proteica , Multimerização Proteica/efeitos dos fármacos , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Sulfonamidas/metabolismo
19.
Science ; 345(6203): 1509-12, 2014 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-25237102

RESUMO

The small number of hematopoietic stem and progenitor cells in cord blood units limits their widespread use in human transplant protocols. We identified a family of chemically related small molecules that stimulates the expansion ex vivo of human cord blood cells capable of reconstituting human hematopoiesis for at least 6 months in immunocompromised mice. The potent activity of these newly identified compounds, UM171 being the prototype, is independent of suppression of the aryl hydrocarbon receptor, which targets cells with more-limited regenerative potential. The properties of UM171 make it a potential candidate for hematopoietic stem cell transplantation and gene therapy.


Assuntos
Sangue Fetal/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Células-Tronco Hematopoéticas/efeitos dos fármacos , Indóis/farmacologia , Pirimidinas/farmacologia , Receptores de Hidrocarboneto Arílico/antagonistas & inibidores , Regeneração/efeitos dos fármacos , Animais , Técnicas de Cultura de Células , Sangue Fetal/citologia , Sangue Fetal/fisiologia , Terapia Genética/métodos , Hematopoese/fisiologia , Transplante de Células-Tronco Hematopoéticas/métodos , Células-Tronco Hematopoéticas/fisiologia , Humanos , Hospedeiro Imunocomprometido , Indóis/química , Camundongos , Pirimidinas/química , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia
20.
Nat Methods ; 11(4): 436-42, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24562423

RESUMO

Leukemic stem cells (LSCs) are considered a major cause of relapse in acute myeloid leukemia (AML). Defining pathways that control LSC self-renewal is crucial for a better understanding of underlying mechanisms and for the development of targeted therapies. However, currently available culture conditions do not prevent spontaneous differentiation of LSCs, which greatly limits the feasibility of cell-based assays. To overcome these constraints we conducted a high-throughput chemical screen and identified small molecules that inhibit differentiation and support LSC activity in vitro. Similar to reports with cord blood stem cells, several of these compounds suppressed the aryl-hydrocarbon receptor (AhR) pathway, which we show to be inactive in vivo and rapidly activated ex vivo in AML cells. We also identified a compound, UM729, that collaborates with AhR suppressors in preventing AML cell differentiation. Together, these findings provide newly defined culture conditions for improved ex vivo culture of primary human AML cells.


Assuntos
Adenina/análogos & derivados , Técnicas de Cultura de Células/métodos , Indóis/farmacologia , Leucemia/metabolismo , Células-Tronco Neoplásicas/fisiologia , Pirimidinas/farmacologia , Adenina/farmacologia , Meios de Cultura Livres de Soro , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Leucemia Mieloide Aguda , Estrutura Molecular
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