Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
J Med Chem ; 67(2): 1262-1313, 2024 01 25.
Artigo em Inglês | MEDLINE | ID: mdl-38180485

RESUMO

The identification of VHL-binding proteolysis targeting chimeras (PROTACs) that potently degrade the BRM protein (also known as SMARCA2) in SW1573 cell-based experiments is described. These molecules exhibit between 10- and 100-fold degradation selectivity for BRM over the closely related paralog protein BRG1 (SMARCA4). They also selectively impair the proliferation of the H1944 "BRG1-mutant" NSCLC cell line, which lacks functional BRG1 protein and is thus highly dependent on BRM for growth, relative to the wild-type Calu6 line. In vivo experiments performed with a subset of compounds identified PROTACs that potently and selectively degraded BRM in the Calu6 and/or the HCC2302 BRG1 mutant NSCLC xenograft models and also afforded antitumor efficacy in the latter system. Subsequent PK/PD analysis established a need to achieve strong BRM degradation (>95%) in order to trigger meaningful antitumor activity in vivo. Intratumor quantitation of mRNA associated with two genes whose transcription was controlled by BRM (PLAU and KRT80) also supported this conclusion.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Quimera de Direcionamento de Proteólise , Xenoenxertos , Carcinoma Pulmonar de Células não Pequenas/patologia , Linhagem Celular , Neoplasias Pulmonares/genética , Fatores de Transcrição/genética , DNA Helicases/genética , Proteínas Nucleares/genética
2.
Nat Commun ; 13(1): 6814, 2022 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-36357397

RESUMO

The mammalian SWItch/Sucrose Non-Fermentable (SWI/SNF) helicase SMARCA4 is frequently mutated in cancer and inactivation results in a cellular dependence on its paralog, SMARCA2, thus making SMARCA2 an attractive synthetic lethal target. However, published data indicates that achieving a high degree of selective SMARCA2 inhibition is likely essential to afford an acceptable therapeutic index, and realizing this objective is challenging due to the homology with the SMARCA4 paralog. Herein we report the discovery of a potent and selective SMARCA2 proteolysis-targeting chimera molecule (PROTAC), A947. Selective SMARCA2 degradation is achieved in the absence of selective SMARCA2/4 PROTAC binding and translates to potent in vitro growth inhibition and in vivo efficacy in SMARCA4 mutant models, compared to wild type models. Global ubiquitin mapping and proteome profiling reveal no unexpected off-target degradation related to A947 treatment. Our study thus highlights the ability to transform a non-selective SMARCA2/4-binding ligand into a selective and efficacious in vivo SMARCA2-targeting PROTAC, and thereby provides a potential new therapeutic opportunity for patients whose tumors contain SMARCA4 mutations.


Assuntos
Neoplasias , Animais , Humanos , Proteólise , Neoplasias/genética , Mutação , Mamíferos , Fatores de Transcrição/genética , DNA Helicases/genética , Proteínas Nucleares/genética
3.
Cancer Cytopathol ; 130(6): 455-468, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35213075

RESUMO

BACKGROUND: Fine-needle aspiration (FNA) is a robust diagnostic technique often used for tissue diagnosis of metastatic carcinoma. For interpretation of FNA cytology, cell block immunohistochemistry (IHC) and clinicocytologic parameters are indispensable. In this review of a large cohort, the current report: 1) describes clinicocytologic parameters and immunoprofiles of aspirates of metastatic carcinoma, 2) compares the predictivity of immunostains and classical approaches for IHC interpretation, and 3) describes machine learning-based algorithms for IHC interpretation. METHODS: Aspirates of metastatic carcinoma that had IHC performed were retrieved. Clinicocytologic parameters, IHC results, the corresponding primary site, and histologic diagnoses were recorded. By using machine learning, decision trees for predicting the primary site were generated, their performance was compared with 2 human-designed algorithms, and the primary site was suggested in the historical diagnosis. RESULTS: In total, 1145 cases were identified. The 6 most populated groups were selected for machine learning and predictive analysis. With IHC input, the decision tree achieved a concordance rate of 94.5% and overall accuracy of 83.6%, which improved to 95.3% and 85.8%, respectively, when clinical data were incorporated and exceeded the human-designed IHC algorithms (P < .001). The historical diagnosis was more accurate unless indeterminate diagnoses were regarded as discordant (P < .001). CDX2 and TTF-1 immunostains had the highest weight in model accuracy, occupied the root of the decision trees, scored higher as features of importance, and outperformed the predictive power of cytokeratins 7 and 20. CONCLUSIONS: Cytokeratins 7 and 20 may be superseded in immunostaining panels, including organ-specific immunostains such as CDX2 and TTF-1. Machine learning generates algorithms that surpasses human-designed algorithms but is inferior to expert assessment integrating clinical and cytologic assessment.


Assuntos
Carcinoma , Algoritmos , Carcinoma/patologia , Humanos , Imuno-Histoquímica , Queratina-7 , Aprendizado de Máquina
4.
Cell Host Microbe ; 29(10): 1521-1530.e10, 2021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34492225

RESUMO

The pore-forming protein gasdermin D (GSDMD) executes lytic cell death called pyroptosis to eliminate the replicative niche of intracellular pathogens. Evolution favors pathogens that circumvent this host defense mechanism. Here, we show that the Shigella ubiquitin ligase IpaH7.8 functions as an inhibitor of GSDMD. Shigella is an enteroinvasive bacterium that causes hemorrhagic gastroenteritis in primates, but not rodents. IpaH7.8 contributes to species specificity by ubiquitinating human, but not mouse, GSDMD and targeting it for proteasomal degradation. Accordingly, infection of human epithelial cells with IpaH7.8-deficient Shigella flexneri results in increased GSDMD-dependent cell death compared with wild type. Consistent with pyroptosis contributing to murine disease resistance, eliminating GSDMD from NLRC4-deficient mice, which are already sensitized to oral infection with Shigella flexneri, leads to further enhanced bacterial replication and increased disease severity. This work highlights a species-specific pathogen arms race focused on maintenance of host cell viability.


Assuntos
Proteínas de Bactérias/metabolismo , Disenteria Bacilar/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Proteínas Citotóxicas Formadoras de Poros/metabolismo , Shigella flexneri/enzimologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Proteínas de Bactérias/genética , Disenteria Bacilar/genética , Disenteria Bacilar/microbiologia , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Feminino , Interações Hospedeiro-Patógeno , Humanos , Camundongos , Camundongos Knockout , Proteínas de Ligação a Fosfato/genética , Proteínas Citotóxicas Formadoras de Poros/genética , Proteólise , Shigella flexneri/genética , Shigella flexneri/fisiologia , Ubiquitina-Proteína Ligases/genética
5.
J Proteome Res ; 19(4): 1533-1547, 2020 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-32159963

RESUMO

Acquisition of drug resistance remains a chief impediment to successful cancer therapy, and we previously described a transient drug-tolerant cancer cell population (DTPs) whose survival is in part dependent on the activities of the histone methyltransferases G9a/EHMT2 and EZH2, the latter being the catalytic component of the polycomb repressive complex 2 (PRC2). Here, we apply multiple proteomic techniques to better understand the role of these histone methyltransferases (HMTs) in the establishment of the DTP state. Proteome-wide comparisons of lysine methylation patterns reveal that DTPs display an increase in methylation on K116 of PRC member Jarid2, an event that helps stabilize and recruit PRC2 to chromatin. We also find that EZH2, in addition to methylating histone H3K27, also can methylate G9a at K185, and that methylated G9a better recruits repressive complexes to chromatin. These complexes are similar to complexes recruited by histone H3 methylated at K9. Finally, a detailed histone post-translational modification (PTM) analysis shows that EZH2, either directly or through its ability to methylate G9a, alters H3K9 methylation in the context of H3 serine 10 phosphorylation, primarily in a cancer cell subpopulation that serves as DTP precursors. We also show that combinations of histone PTMs recruit a different set of complexes to chromatin, shedding light on the temporal mechanisms that contribute to drug tolerance.


Assuntos
Neoplasias , Proteômica , Tolerância a Medicamentos , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histonas/metabolismo , Metilação , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo
6.
Cell Rep ; 24(7): 1722-1729, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30110629

RESUMO

Acetylation of histone H3 at lysine 27 is a well-defined marker of enhancer activity. However, the functional impact of this modification at enhancers is poorly understood. Here, we use a chemical genetics approach to acutely block the function of the cAMP response element binding protein (CREB) binding protein (CBP)/P300 bromodomain in models of hematological malignancies and describe a consequent loss of H3K27Ac specifically from enhancers, despite the continued presence of CBP/P300 at chromatin. Using this approach to dissect the role of H3K27Ac at enhancers, we identify a critical role for this modification in the production of enhancer RNAs and transcription of enhancer-regulated gene networks.


Assuntos
Elementos Facilitadores Genéticos , Histonas/metabolismo , Processamento de Proteína Pós-Traducional , RNA Neoplásico/genética , Fatores de Transcrição de p300-CBP/genética , Acetilação , Sítios de Ligação , Linhagem Celular Tumoral , Cromatina/química , Cromatina/metabolismo , Neoplasias Hematológicas/genética , Neoplasias Hematológicas/metabolismo , Histonas/genética , Humanos , Lisina/metabolismo , Ligação Proteica , Domínios Proteicos , RNA Neoplásico/metabolismo , Transcrição Gênica , Fatores de Transcrição de p300-CBP/metabolismo
7.
Sci Immunol ; 3(22)2018 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-29678836

RESUMO

Loss of function of the nuclear deubiquitinating enzyme BRCA1-associated protein-1 (BAP1) is associated with a wide spectrum of cancers. We report that tamoxifen-induced BAP1 deletion in adult mice resulted in severe thymic atrophy. BAP1 was critical for T cell development at several stages. In the thymus, BAP1 was required for progression through the pre-T cell receptor checkpoint. Peripheral T cells lacking BAP1 demonstrated a defect in homeostatic and antigen-driven expansion. Deletion of BAP1 resulted in suppression of E2F target genes and defects in cell cycle progression, which was dependent on the catalytic activity of BAP1, but did not require its interaction with host cell factor-1 (HCF-1). Loss of BAP1 led to increased monoubiquitination of histone H2A at Lys119 (H2AK119ub) throughout the T cell lineage, in particular in immature thymocytes, but did not alter trimethylation of histone H3 at Lys27 (H3K27me3). Deletion of BAP1 also abrogated B cell development in the bone marrow. Our findings uncover a nonredundant function for BAP1 in maintaining the lymphoid lineage.


Assuntos
Linfócitos T/metabolismo , Timócitos/metabolismo , Timo/metabolismo , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Animais , Atrofia , Ciclo Celular/genética , Perfilação da Expressão Gênica , Histonas/genética , Histonas/metabolismo , Lisina/genética , Lisina/metabolismo , Camundongos Knockout , Camundongos Transgênicos , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Timo/patologia , Proteínas Supressoras de Tumor/metabolismo , Ubiquitina Tiolesterase/metabolismo , Ubiquitinação
8.
Clin Pharmacol Drug Dev ; 7(4): 435-440, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29058801

RESUMO

Venetoclax has been approved in the United States, Europe, Canada, and Australia for appropriate patients with difficult-to-treat chronic lymphocytic leukemia (CLL). The objective of this phase 1 study was to evaluate the pharmacokinetics of venetoclax in Chinese subjects to inform the dose selection of venetoclax in a phase 2 study of patients with relapsed/refractory (R/R) CLL in China. Twelve healthy first-generation Han Chinese subjects received a single 100-mg dose of venetoclax following a low-fat breakfast. Pharmacokinetic parameters were estimated using noncompartmental methods. After a single dose of venetoclax in healthy Chinese subjects, the median time to peak concentration was 6 hours (range, 4 to 6 hours), and the mean ± SD Cmax , AUCinf , and terminal half-life were 1.0 ± 0.32 µg/mL, 12.6 ± 5.4 µg·h/mL, and 18.4 ± 2.97 hours, respectively. On average, venetoclax Cmax and AUCinf values were 94% and 66% higher, respectively, in Chinese subjects compared with those observed historically for non-Asian subjects receiving the same dose. Based on these pharmacokinetic results and the established exposure-response relationship of venetoclax in non-Asian CLL subjects, a 400-mg once-daily dosage regimen was selected for evaluating the venetoclax pharmacokinetics, efficacy, and safety in the venetoclax phase 2 open-label study in Chinese subjects with R/R CLL.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Proteínas Proto-Oncogênicas c-bcl-2/antagonistas & inibidores , Sulfonamidas/farmacocinética , Adulto , Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , China/etnologia , Cálculos da Dosagem de Medicamento , Feminino , Meia-Vida , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Sulfonamidas/administração & dosagem
9.
Cancer Res ; 78(5): 1127-1139, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29282222

RESUMO

The H3K4 demethylase KDM5B is amplified and overexpressed in luminal breast cancer, suggesting it might constitute a potential cancer therapy target. Here, we characterize, in breast cancer cells, the molecular effects of a recently developed small-molecule inhibitor of the KDM5 family of proteins (KDM5i), either alone or in combination with the DNA-demethylating agent 5-aza-2'-deoxycytidine (DAC). KDM5i treatment alone increased expression of a small number of genes, whereas combined treatment with DAC enhanced the effects of the latter for increasing expression of hundreds of DAC-responsive genes. ChIP-seq studies revealed that KDM5i resulted in the broadening of existing H3K4me3 peaks. Furthermore, cells treated with the drug combination exhibited increased promoter and gene body H3K4me3 occupancy at DAC-responsive genes compared with DAC alone. Importantly, treatment with either DAC or DAC+KDM5i induced a dramatic increase in H3K27ac at enhancers with an associated significant increase in target gene expression, suggesting a previously unappreciated effect of DAC on transcriptional regulation. KDM5i synergized with DAC to reduce the viability of luminal breast cancer cells in in vitro assays. Our study provides the first look into the molecular effects of a novel KDM5i compound and suggests that combinatorial inhibition along with DAC represents a new area to explore in translational epigenetics.Significance: This study offers a first look into the molecular effects of a novel KDM5 inhibitory compound, suggesting how its use in combination with DNA methylation inhibitors presents new opportunities to explore in translational cancer epigenetics. Cancer Res; 78(5); 1127-39. ©2017 AACR.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Metilação de DNA , Decitabina/farmacologia , Inibidores Enzimáticos/farmacologia , Genoma Humano , Histonas/química , Histona Desmetilases com o Domínio Jumonji/antagonistas & inibidores , Proteínas Nucleares/antagonistas & inibidores , Proteínas Repressoras/antagonistas & inibidores , Apoptose , Neoplasias da Mama/enzimologia , Neoplasias da Mama/patologia , Proliferação de Células , Epigênese Genética , Feminino , Ensaios de Triagem em Larga Escala , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Repressoras/metabolismo , Células Tumorais Cultivadas
10.
Cancer Res ; 77(24): 7027-7037, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29046337

RESUMO

Antibody-drug conjugates (ADC) are designed to selectively bind to tumor antigens via the antibody and release their cytotoxic payload upon internalization. Controllable payload release through judicious design of the linker has been an early technological milestone. Here, we examine the effect of the protease-cleavable valine-citrulline [VC(S)] linker on ADC efficacy. The VC(S) linker was designed to be cleaved by cathepsin B, a lysosomal cysteine protease. Surprisingly, suppression of cathepsin B expression via CRISPR-Cas9 gene deletion or shRNA knockdown had no effect on the efficacy of ADCs with VC(S) linkers armed with a monomethyl auristatin E (MMAE) payload. Mass spectrometry studies of payload release suggested that other cysteine cathepsins can cleave the VC(S) linker. Also, ADCs with a nonprotease-cleavable enantiomer, the VC(R) isomer, mediated effective cell killing with a cysteine-VC(R)-MMAE catabolite generated by lysosomal catabolism. Based on these observations, we altered the payload to a pyrrolo[2,1-c][1,4]benzodiazepine dimer (PBD) conjugate that requires linker cleavage in order to bind its DNA target. Unlike the VC-MMAE ADCs, the VC(S)-PBD ADC is at least 20-fold more cytotoxic than the VC(R)-PBD ADC. Our findings reveal that the VC(S) linker has multiple paths to produce active catabolites and that antibody and intracellular targets are more critical to ADC efficacy. These results suggest that protease-cleavable linkers are unlikely to increase the therapeutic index of ADCs and that resistance based on linker processing is improbable. Cancer Res; 77(24); 7027-37. ©2017 AACR.


Assuntos
Anticorpos Monoclonais/metabolismo , Antineoplásicos/metabolismo , Catepsina B/fisiologia , Imunoconjugados/metabolismo , Pró-Fármacos/metabolismo , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos/uso terapêutico , Catepsina B/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Citrulina/metabolismo , Ensaios de Seleção de Medicamentos Antitumorais , Células HEK293 , Humanos , Imunoconjugados/uso terapêutico , Oligopeptídeos , Pró-Fármacos/uso terapêutico , Proteólise , Valina/metabolismo
11.
J Cell Biol ; 216(11): 3535-3549, 2017 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-28887438

RESUMO

A propensity for rewiring genetic and epigenetic regulatory networks, thus enabling sustained cell proliferation, suppression of apoptosis, and the ability to evade the immune system, is vital to cancer cell propagation. An increased understanding of how this is achieved is critical for identifying or improving therapeutic interventions. In this study, using acute myeloid leukemia (AML) human cell lines and a custom CRISPR/Cas9 screening platform, we identify the H3K9 methyltransferase SETDB1 as a novel, negative regulator of innate immunity. SETDB1 is overexpressed in many cancers, and loss of this gene in AML cells triggers desilencing of retrotransposable elements that leads to the production of double-stranded RNAs (dsRNAs). This is coincident with induction of a type I interferon response and apoptosis through the dsRNA-sensing pathway. Collectively, our findings establish a unique gene regulatory axis that cancer cells can exploit to circumvent the immune system.


Assuntos
Inativação Gênica , Interferon Tipo I/metabolismo , Leucemia Mieloide Aguda/enzimologia , Proteínas Metiltransferases/metabolismo , Retroelementos , Apoptose , Sistemas CRISPR-Cas , Linhagem Celular Tumoral , Sobrevivência Celular , Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Histona-Lisina N-Metiltransferase , Humanos , Imunidade Inata , Interferon Tipo I/imunologia , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/patologia , Proteínas Metiltransferases/genética , Interferência de RNA , RNA de Cadeia Dupla/biossíntese , RNA de Cadeia Dupla/genética , Transdução de Sinais , Fatores de Tempo , Transfecção , Evasão Tumoral
12.
Int J Surg Case Rep ; 39: 185-187, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28846952

RESUMO

INTRODUCTION: Incisional hernia is not an uncommon complication after abdominal operation, and laparoscopic ventral hernia repair with mesh is commonly performed nowadays. It is thought to have less complication compare to the traditional open repair, yet late complication is still observed occasionally and can be disastrous. CASE REPORT: We hereby report a case of abdominal wall necrotizing fasciitis 21 months after laparoscopic incisional hernia repair in lower midline with dual mesh, due to mesh migration and erosion into urinary bladder, resulting in fistulation between bladder and abdominal wall. Repeated debridement and removal of mesh was required for sepsis control and the patient required intensive care support due to multi-organ failure. Subsequent repair of urinary bladder and abdominoplasty was performed after condition stabilized. CONCLUSION: This case was the first reported incident with bladder erosion by dual mesh causing vesico-cutaneous fistula complicated with necrotizing fasciitis. Although dual mesh theoretically reduces the risk of mesh erosion, mesh erosion to viscera can still happen and cause severe complication. Its risk should be balanced and discussed with patient with full consent.

13.
Cancer Cell ; 32(2): 221-237.e13, 2017 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-28781121

RESUMO

Maintenance of phenotypic heterogeneity within cell populations is an evolutionarily conserved mechanism that underlies population survival upon stressful exposures. We show that the genomes of a cancer cell subpopulation that survives treatment with otherwise lethal drugs, the drug-tolerant persisters (DTPs), exhibit a repressed chromatin state characterized by increased methylation of histone H3 lysines 9 and 27 (H3K9 and H3K27). We also show that survival of DTPs is, in part, maintained by regulators of H3K9me3-mediated heterochromatin formation and that the observed increase in H3K9me3 in DTPs is most prominent over long interspersed repeat element 1 (LINE-1). Disruption of the repressive chromatin over LINE-1 elements in DTPs results in DTP ablation, which is partially rescued by reducing LINE-1 expression or function.


Assuntos
Cromatina/genética , Resistencia a Medicamentos Antineoplásicos/genética , Repressão Epigenética/efeitos dos fármacos , Elementos Nucleotídeos Longos e Dispersos/genética , Neoplasias/patologia , Animais , Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica/efeitos dos fármacos , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Metilação , Camundongos , Camundongos Nus , Camundongos SCID , Neoplasias/tratamento farmacológico , Neoplasias/genética , Estresse Fisiológico , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Semin Immunopathol ; 39(4): 487-500, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28451787

RESUMO

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by persistent joint inflammation. Without adequate treatment, patients with RA will develop joint deformity and progressive functional impairment. With the implementation of treat-to-target strategies and availability of biologic therapies, the outcomes for patients with RA have significantly improved. However, the unmet need in the treatment of RA remains high as some patients do not respond sufficiently to the currently available agents, remission is not always achieved and refractory disease is not uncommon. With better understanding of the pathophysiology of RA, new therapeutic approaches are emerging. Apart from more selective Janus kinase inhibition, there is a great interest in the granulocyte macrophage-colony stimulating factor pathway, Bruton's tyrosine kinase pathway, phosphoinositide-3-kinase pathway, neural stimulation and dendritic cell-based therapeutics. In this review, we will discuss the therapeutic potential of these novel approaches.


Assuntos
Artrite Reumatoide/terapia , Terapia de Alvo Molecular , Tirosina Quinase da Agamaglobulinemia , Animais , Antirreumáticos/farmacologia , Antirreumáticos/uso terapêutico , Artrite Reumatoide/etiologia , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Biomarcadores , Terapia Combinada , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Humanos , Imunoterapia , Janus Quinases/metabolismo , Neuroimunomodulação/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Transdução de Sinais/efeitos dos fármacos
15.
Nat Chem Biol ; 12(7): 531-8, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27214401

RESUMO

The KDM5 family of histone demethylases catalyzes the demethylation of histone H3 on lysine 4 (H3K4) and is required for the survival of drug-tolerant persister cancer cells (DTPs). Here we report the discovery and characterization of the specific KDM5 inhibitor CPI-455. The crystal structure of KDM5A revealed the mechanism of inhibition of CPI-455 as well as the topological arrangements of protein domains that influence substrate binding. CPI-455 mediated KDM5 inhibition, elevated global levels of H3K4 trimethylation (H3K4me3) and decreased the number of DTPs in multiple cancer cell line models treated with standard chemotherapy or targeted agents. These findings show that pretreatment of cancer cells with a KDM5-specific inhibitor results in the ablation of a subpopulation of cancer cells that can serve as the founders for therapeutic relapse.


Assuntos
Antineoplásicos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Proteína 2 de Ligação ao Retinoblastoma/antagonistas & inibidores , Antineoplásicos/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/química , Humanos , Modelos Moleculares , Estrutura Molecular , Proteína 2 de Ligação ao Retinoblastoma/metabolismo , Relação Estrutura-Atividade
16.
PLoS One ; 10(9): e0138350, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26379037

RESUMO

Manganese plays a central role in cellular detoxification of reactive oxygen species (ROS). Therefore, manganese acquisition is considered to be important for bacterial pathogenesis by counteracting the oxidative burst of phagocytic cells during host infection. However, detailed analysis of the interplay between bacterial manganese acquisition and phagocytic cells and its impact on bacterial pathogenesis has remained elusive for Staphylococcus aureus, a major human pathogen. Here, we show that a mntC mutant, which lacks the functional manganese transporter MntABC, was more sensitive to killing by human neutrophils but not murine macrophages, unless the mntC mutant was pre-exposed to oxidative stress. Notably, the mntC mutant formed strikingly small colonies when recovered from both type of phagocytic cells. We show that this phenotype is a direct consequence of the inability of the mntC mutant to reinitiate growth after exposure to phagocytic oxidative burst. Transcript and quantitative proteomics analyses revealed that the manganese-dependent ribonucleotide reductase complex NrdEF, which is essential for DNA synthesis and repair, was highly induced in the mntC mutant under oxidative stress conditions including after phagocytosis. Since NrdEF proteins are essential for S. aureus viability we hypothesize that cells lacking MntABC might attempt to compensate for the impaired function of NrdEF by increasing their expression. Our data suggest that besides ROS detoxification, functional manganese acquisition is likely crucial for S. aureus pathogenesis by repairing oxidative damages, thereby ensuring efficient bacterial growth after phagocytic oxidative burst, which is an attribute critical for disseminating and establishing infection in the host.


Assuntos
Proteínas de Bactérias/genética , Replicação do DNA/genética , Manganês/metabolismo , Proteínas de Membrana Transportadoras/genética , Estresse Oxidativo/genética , Explosão Respiratória/genética , Staphylococcus aureus/genética , Animais , Regulação Bacteriana da Expressão Gênica/genética , Humanos , Macrófagos/microbiologia , Camundongos , Neutrófilos/microbiologia , Fagocitose/genética , Proteômica/métodos , Espécies Reativas de Oxigênio/metabolismo , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/metabolismo
17.
Sci Rep ; 5: 13204, 2015 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-26278959

RESUMO

Patients receive dual antiplatelet therapy (DAPT) for 6-12 months after drug-eluting stents (DES) implantation. The efficacy and safety of prolonged DAPT has been questioned. Therefore, we performed a meta-analysis on randomised trials comparing different DAPT durations. Literature was searched on trials comparing different DAPT durations. For inclusion, reports must report frequency of cardiovascular and bleeding events. Ten trials were included. Compared to 12 months, DAPT beyond 12 months was associated with fewer myocardial infarctions (OR 0.58 95%CI: 0.40-0.84) and stent thrombosis (OR 0.35 95%CI: 0.20-0.62), but more major bleeds (OR 1.60 95%CI: 1.22-2.11) and all-cause (OR 1.30 95%CI: 1.02-1.66) mortality. There was no significant alteration in risk of stroke (OR 0.93 95%CI: 0.66-1.31) or cardiac (OR 1.12 95%CI: 0.73-1.71) mortality. Compared to less than 12 months DAPT, 12 months DAPT did not reduce risk of myocardial infarction, stent thrombosis, strokes, cardiac or all-cause mortality, but increased the risk of major bleeds (OR 1.60 95%CI: 1.22-2.11). DAPT beyond 12 months reduce risk of myocardial infarction and stent thrombosis, but there is substantial increase in major bleeding risk and all-cause mortality which need to be addressed. DAPT beyond 12 months does not appear to alter the risk of stroke.


Assuntos
Aspirina/uso terapêutico , Stents Farmacológicos , Infarto do Miocárdio/tratamento farmacológico , Inibidores da Agregação Plaquetária/uso terapêutico , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico , Trombose/tratamento farmacológico , Ensaios Clínicos como Assunto , Bases de Dados Factuais , Stents Farmacológicos/efeitos adversos , Hemorragia/etiologia , Humanos , Razão de Chances , Próteses e Implantes , Risco
18.
Mol Cell Proteomics ; 14(4): 1148-58, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25680960

RESUMO

Mass spectrometry is a powerful alternative to antibody-based methods for the analysis of histone post-translational modifications (marks). A key development in this approach was the deliberate propionylation of histones to improve sequence coverage across the lysine-rich and hydrophilic tails that bear most modifications. Several marks continue to be problematic however, particularly di- and tri-methylated lysine 4 of histone H3 which we found to be subject to substantial and selective losses during sample preparation and liquid chromatography-mass spectrometry. We developed a new method employing a "one-pot" hybrid chemical derivatization of histones, whereby an initial conversion of free lysines to their propionylated forms under mild aqueous conditions is followed by trypsin digestion and labeling of new peptide N termini with phenyl isocyanate. High resolution mass spectrometry was used to collect qualitative and quantitative data, and a novel web-based software application (Fishtones) was developed for viewing and quantifying histone marks in the resulting data sets. Recoveries of 53 methyl, acetyl, and phosphoryl marks on histone H3.1 were improved by an average of threefold overall, and over 50-fold for H3K4 di- and tri-methyl marks. The power of this workflow for epigenetic research and drug discovery was demonstrated by measuring quantitative changes in H3K4 trimethylation induced by small molecule inhibitors of lysine demethylases and siRNA knockdown of epigenetic modifiers ASH2L and WDR5.


Assuntos
Histonas/metabolismo , Espectrometria de Massas/métodos , Processamento de Proteína Pós-Traducional , Coloração e Rotulagem/métodos , Cromatografia Líquida , Técnicas de Silenciamento de Genes , Células HEK293 , Células HeLa , Histona Desmetilases/metabolismo , Humanos , Lisina/metabolismo , Metilação , Peptídeos/metabolismo , Propionatos/metabolismo , RNA Interferente Pequeno/metabolismo , Padrões de Referência , Tripsina/metabolismo
19.
Nature ; 515(7528): 572-6, 2014 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-25428506

RESUMO

Human tumours typically harbour a remarkable number of somatic mutations. If presented on major histocompatibility complex class I molecules (MHCI), peptides containing these mutations could potentially be immunogenic as they should be recognized as 'non-self' neo-antigens by the adaptive immune system. Recent work has confirmed that mutant peptides can serve as T-cell epitopes. However, few mutant epitopes have been described because their discovery required the laborious screening of patient tumour-infiltrating lymphocytes for their ability to recognize antigen libraries constructed following tumour exome sequencing. We sought to simplify the discovery of immunogenic mutant peptides by characterizing their general properties. We developed an approach that combines whole-exome and transcriptome sequencing analysis with mass spectrometry to identify neo-epitopes in two widely used murine tumour models. Of the >1,300 amino acid changes identified, ∼13% were predicted to bind MHCI, a small fraction of which were confirmed by mass spectrometry. The peptides were then structurally modelled bound to MHCI. Mutations that were solvent-exposed and therefore accessible to T-cell antigen receptors were predicted to be immunogenic. Vaccination of mice confirmed the approach, with each predicted immunogenic peptide yielding therapeutically active T-cell responses. The predictions also enabled the generation of peptide-MHCI dextramers that could be used to monitor the kinetics and distribution of the anti-tumour T-cell response before and after vaccination. These findings indicate that a suitable prediction algorithm may provide an approach for the pharmacodynamic monitoring of T-cell responses as well as for the development of personalized vaccines in cancer patients.


Assuntos
Exoma/genética , Fenômenos Imunogenéticos/genética , Espectrometria de Massas , Mutação , Neoplasias/genética , Animais , Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/imunologia , Linhagem Celular Tumoral , Feminino , Perfilação da Expressão Gênica , Imunidade Celular/imunologia , Imunoprecipitação , Camundongos , Camundongos Endogâmicos C57BL , Modelos Moleculares , Neoplasias/imunologia , Peptídeos/genética , Estrutura Terciária de Proteína
20.
Clin Exp Hypertens ; 36(4): 206-10, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23786432

RESUMO

PURPOSE: Hypertension is associated with inflammation. Whether the inflammation caused by allergic diseases such as allergic rhinitis can predispose to hypertension is controversial. Therefore, we studied the association between hay fever and hypertension in the United States National Health and Nutrition Examination Survey (NHANES). METHODS: We analyzed data on 1883 men and 2029 women in NHANES 2005-2006. We included participants aged 20 years or older who had valid data on hay fever and hypertension. RESULTS: 13.5% of the participants had a previous diagnosis of hay fever and 36.2% of them had hypertension. There were ethnic differences in the prevalence of previous hay fever diagnosis (p < 0.001) and hypertension (p < 0.001). There was no significant association between previous hay fever diagnosis and hypertension in men in any age group. The association between previous hay fever diagnosis and hypertension in women was significant in those aged 20-39 years (OR = 2.59, 95%CI = 1.26-5.30, p = 0.013). The association between previous hay fever diagnosis and hypertension in women aged form 20 to 39 years remained significant after adjustment for age, race and body mass index (OR = 2.74, 95%CI = 1.48-5.06, p = 0.003). After further adjustment for physical activity, alcohol consumption and smoking, the association was not attenuated (OR = 2.68, 95%CI = 1.38-5.18, p = 0.006). Further adjustment for liver enzymes, C-reactive protein and immunoglobulin E level attenuated the association slightly (OR = 2.72, 95%CI = 1.19-6.22, p = 0.021). CONCLUSIONS: In this nationally representative population-based survey, previous hay fever diagnosis is not significantly associated with hypertension in adults overall. There is an association in subgroup of young women aged 20-39. Further work is needed to confirm that this is a true association.


Assuntos
Hipertensão/epidemiologia , Inquéritos Nutricionais/métodos , Rinite Alérgica Sazonal/epidemiologia , Adulto , Distribuição por Idade , Fatores Etários , Pressão Sanguínea , Feminino , Seguimentos , Humanos , Hipertensão/etiologia , Hipertensão/fisiopatologia , Incidência , Masculino , Pessoa de Meia-Idade , Prevalência , Prognóstico , Estudos Retrospectivos , Rinite Alérgica Sazonal/complicações , Rinite Alérgica Sazonal/diagnóstico , Distribuição por Sexo , Estados Unidos/epidemiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA