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1.
Genome Biol ; 25(1): 68, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38468286

RESUMO

BACKGROUND: In rheumatoid arthritis (RA), the activation of T and B cell clones specific for self-antigens leads to the chronic inflammation of the synovium. Here, we perform an in-depth quantitative analysis of the seven chains that comprise the adaptive immune receptor repertoire (AIRR) in RA. RESULTS: In comparison to controls, we show that RA patients have multiple and strong differences in the B cell receptor repertoire including reduced diversity as well as altered isotype, chain, and segment frequencies. We demonstrate that therapeutic tumor necrosis factor inhibition partially restores this alteration but find a profound difference in the underlying biochemical reactivities between responders and non-responders. Combining the AIRR with HLA typing, we identify the specific T cell receptor repertoire associated with disease risk variants. Integrating these features, we further develop a molecular classifier that shows the utility of the AIRR as a diagnostic tool. CONCLUSIONS: Simultaneous sequencing of the seven chains of the human AIRR reveals novel features associated with the disease and clinically relevant phenotypes, including response to therapy. These findings show the unique potential of AIRR to address precision medicine in immune-related diseases.


Assuntos
Artrite Reumatoide , Humanos , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/genética , Membrana Sinovial , Linfócitos B , Fator de Necrose Tumoral alfa , Fenótipo
2.
Genome Res ; 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37852782

RESUMO

Transcription factors (TFs) are trans-acting proteins that bind cis-regulatory elements (CREs) in DNA to control gene expression. Here, we analyzed the genomic localization profiles of 529 sequence-specific TFs and 151 cofactors and chromatin regulators in the human cancer cell line HepG2, for a total of 680 broadly termed DNA-associated proteins (DAPs). We used this deep collection to model each TF's impact on gene expression, and identified a cohort of 26 candidate transcriptional repressors. We examine high occupancy target (HOT) sites in the context of three-dimensional genome organization and show biased motif placement in distal-promoter connections involving HOT sites. We also found a substantial number of closed chromatin regions with multiple DAPs bound, and explored their properties, finding that a MAFF/MAFK TF pair correlates with transcriptional repression. Altogether, these analyses provide novel insights into the regulatory logic of the human cell line HepG2 genome and show the usefulness of large genomic analyses for elucidation of individual TF functions.

3.
EBioMedicine ; 80: 104053, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35576644

RESUMO

BACKGROUND: Rheumatoid arthritis (RA) is a chronic, immune-mediated inflammatory disease of the joints that has been associated with variation in the peripheral blood methylome. In this study, we aim to identify epigenetic variation that is associated with the response to tumor necrosis factor inhibitor (TNFi) therapy. METHODS: Peripheral blood genome-wide DNA methylation profiles were analyzed in a discovery cohort of 62 RA patients at baseline and at week 12 of TNFi therapy. DNA methylation of individual CpG sites and enrichment of biological pathways were evaluated for their association with drug response. Using a novel cell deconvolution approach, altered DNA methylation associated with TNFi response was also tested in the six main immune cell types in blood. Validation of the results was performed in an independent longitudinal cohort of 60 RA patients. FINDINGS: Treatment with TNFi was associated with significant longitudinal peripheral blood methylation changes in biological pathways related to RA (FDR<0.05). 139 biological functions were modified by therapy, with methylation levels changing systematically towards a signature similar to that of healthy controls. Differences in the methylation profile of T cell activation and differentiation, GTPase-mediated signaling, and actin filament organization pathways were associated with the clinical response to therapy. Cell type deconvolution analysis identified CpG sites in CD4+T, NK, neutrophils and monocytes that were significantly associated with the response to TNFi. INTERPRETATION: Our results show that treatment with TNFi restores homeostatic blood methylation in RA. The clinical response to TNFi is associated to methylation variation in specific biological pathways, and it involves cells from both the innate and adaptive immune systems. FUNDING: The Instituto de Salud Carlos III.


Assuntos
Antirreumáticos , Artrite Reumatoide , Antirreumáticos/farmacologia , Antirreumáticos/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/genética , Estudos de Coortes , Metilação de DNA , Humanos , Inibidores do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa/metabolismo
4.
Sci Rep ; 11(1): 14053, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234242

RESUMO

The kidney proximal tubule is the primary site for solute reabsorption, secretion and where kidney diseases can originate, including drug-induced toxicity. Two-dimensional cell culture systems of the human proximal tubule cells (hPTCs) are often used to study these processes. However, these systems fail to model the interplay between filtrate flow, fluid shear stress (FSS), and functionality essential for understanding renal diseases and drug toxicity. The impact of FSS exposure on gene expression and effects of FSS at differing rates on gene expression in hPTCs has not been thoroughly investigated. Here, we performed RNA-sequencing of human RPTEC/TERT1 cells in a microfluidic chip-based 3D model to determine transcriptomic changes. We measured transcriptional changes following treatment of cells in this device at three different fluidic shear stress. We observed that FSS changes the expression of PTC-specific genes and impacted genes previously associated with renal diseases in genome-wide association studies (GWAS). At a physiological FSS level, we observed cell morphology, enhanced polarization, presence of cilia, and transport functions using albumin reabsorption via endocytosis and efflux transport. Here, we present a dynamic view of hPTCs response to FSS with increasing fluidic shear stress conditions and provide insight into hPTCs cellular function under biologically relevant conditions.


Assuntos
Células Epiteliais/metabolismo , Túbulos Renais/citologia , Modelos Biológicos , Estresse Mecânico , Transcriptoma , Transporte Biológico , Biomarcadores , Biologia Computacional/métodos , Endocitose/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Humanos , Túbulos Renais Proximais/citologia , Resistência ao Cisalhamento , Transdução de Sinais
5.
BMC Cancer ; 21(1): 632, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34049503

RESUMO

BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) patients suffer poor outcomes, including a five-year survival of below 10%. Poor outcomes result in part from therapeutic resistance that limits the impact of cytotoxic first-line therapy. Novel therapeutic approaches are needed, but currently no targeted therapies exist to treat PDAC. METHODS: To assess cellular resistance mechanisms common to four cytotoxic chemotherapies (gemcitabine, 5-fluorouracil, irinotecan, and oxaliplatin) used to treat PDAC patients, we performed four genome-wide CRISPR activation (CRISPRact) and CRISPR knock-out (CRISPRko) screens in two common PDAC cell lines (Panc-1 and BxPC3). We used pathway analysis to identify gene sets enriched among our hits and conducted RNA-sequencing and chromatin immunoprecipitation-sequencing (ChIP-seq) to characterize top hits from our screen. We used scratch assays to assess changes in cellular migration with HDAC1 overexpression. RESULTS: Our data revealed activation of ABCG2, a well-described efflux pump, as the most consistent mediator of resistance in each of our screens. CRISPR-mediated activation of genes involved in transcriptional co-repressor complexes also conferred resistance to multiple drugs. Expression of many of these genes, including HDAC1, is associated with reduced survival in PDAC patients. Up-regulation of HDAC1 in vitro increased promoter occupancy and expression of several genes involved in the epithelial-to-mesenchymal transition (EMT). These cells also displayed phenotypic changes in cellular migration consistent with activation of the EMT pathway. The expression changes resulting from HDAC1 activation were also observed with activation of several other co-repressor complex members. Finally, we developed a publicly available analysis tool, PancDS, which integrates gene expression profiles with our screen results to predict drug sensitivity in resected PDAC tumors and cell lines. CONCLUSION: Our results provide a comprehensive resource for identifying cellular mechanisms of drug resistance in PDAC, mechanistically implicate HDAC1, and co-repressor complex members broadly, in multi-drug resistance, and provide an analytical tool for predicting treatment response in PDAC tumors and cell lines.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Ductal Pancreático/tratamento farmacológico , Resistência a Múltiplos Medicamentos/genética , Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias Pancreáticas/tratamento farmacológico , Antineoplásicos/uso terapêutico , Sistemas CRISPR-Cas/genética , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/mortalidade , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Sequenciamento de Cromatina por Imunoprecipitação , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Transição Epitelial-Mesenquimal/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , RNA-Seq
7.
Cancer Res ; 80(20): 4355-4370, 2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32816914

RESUMO

Breast cancers are divided into subtypes with different prognoses and treatment responses based on global differences in gene expression. Luminal breast cancer gene expression and proliferation are driven by estrogen receptor alpha, and targeting this transcription factor is the most effective therapy for this subtype. By contrast, it remains unclear which transcription factors drive the gene expression signature that defines basal-like triple-negative breast cancer, and there are no targeted therapies approved to treat this aggressive subtype. In this study, we utilized integrated genomic analysis of DNA methylation, chromatin accessibility, transcription factor binding, and gene expression in large collections of breast cancer cell lines and patient tumors to identify transcription factors responsible for the basal-like gene expression program. Glucocorticoid receptor (GR) and STAT3 bind to the same genomic regulatory regions, which were specifically open and unmethylated in basal-like breast cancer. These transcription factors cooperated to regulate expression of hundreds of genes in the basal-like gene expression signature, which were associated with poor prognosis. Combination treatment with small-molecule inhibitors of both transcription factors resulted in synergistic decreases in cell growth in cell lines and patient-derived organoid models. This study demonstrates that GR and STAT3 cooperate to regulate the basal-like breast cancer gene expression program and provides the basis for improved therapy for basal-like triple-negative breast cancer through rational combination of STAT3 and GR inhibitors. SIGNIFICANCE: This study demonstrates that GR and STAT3 cooperate to activate the canonical gene expression signature of basal-like triple-negative breast cancer and that combination treatment with STAT3 and GR inhibitors could provide synergistic therapeutic efficacy.


Assuntos
Receptores de Glucocorticoides/genética , Fator de Transcrição STAT3/genética , Neoplasias de Mama Triplo Negativas/genética , Neoplasias de Mama Triplo Negativas/patologia , Sítios de Ligação , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Metilação de DNA , Dexametasona/farmacologia , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Estimativa de Kaplan-Meier , Prognóstico , Receptores de Glucocorticoides/metabolismo , Sequências Reguladoras de Ácido Nucleico , Fator de Transcrição STAT3/metabolismo , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/mortalidade
8.
Nature ; 583(7818): 720-728, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32728244

RESUMO

Transcription factors are DNA-binding proteins that have key roles in gene regulation1,2. Genome-wide occupancy maps of transcriptional regulators are important for understanding gene regulation and its effects on diverse biological processes3-6. However, only a minority of the more than 1,600 transcription factors encoded in the human genome has been assayed. Here we present, as part of the ENCODE (Encyclopedia of DNA Elements) project, data and analyses from chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq) experiments using the human HepG2 cell line for 208 chromatin-associated proteins (CAPs). These comprise 171 transcription factors and 37 transcriptional cofactors and chromatin regulator proteins, and represent nearly one-quarter of CAPs expressed in HepG2 cells. The binding profiles of these CAPs form major groups associated predominantly with promoters or enhancers, or with both. We confirm and expand the current catalogue of DNA sequence motifs for transcription factors, and describe motifs that correspond to other transcription factors that are co-enriched with the primary ChIP target. For example, FOX family motifs are enriched in ChIP-seq peaks of 37 other CAPs. We show that motif content and occupancy patterns can distinguish between promoters and enhancers. This catalogue reveals high-occupancy target regions at which many CAPs associate, although each contains motifs for only a minority of the numerous associated transcription factors. These analyses provide a more complete overview of the gene regulatory networks that define this cell type, and demonstrate the usefulness of the large-scale production efforts of the ENCODE Consortium.


Assuntos
Sequenciamento de Cromatina por Imunoprecipitação , Cromatina/genética , Cromatina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Anotação de Sequência Molecular , Sequências Reguladoras de Ácido Nucleico/genética , Conjuntos de Dados como Assunto , Elementos Facilitadores Genéticos/genética , Células Hep G2 , Humanos , Motivos de Nucleotídeos/genética , Regiões Promotoras Genéticas/genética , Ligação Proteica , Fatores de Transcrição/metabolismo
9.
Genome Res ; 30(7): 939-950, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32616518

RESUMO

DNA-associated proteins (DAPs) classically regulate gene expression by binding to regulatory loci such as enhancers or promoters. As expanding catalogs of genome-wide DAP binding maps reveal thousands of loci that, unlike the majority of conventional enhancers and promoters, associate with dozens of different DAPs with apparently little regard for motif preference, an understanding of DAP association and coordination at such regulatory loci is essential to deciphering how these regions contribute to normal development and disease. In this study, we aggregated publicly available ChIP-seq data from 469 human DAPs assayed in three cell lines and integrated these data with an orthogonal data set of 352 nonredundant, in vitro-derived motifs mapped to the genome within DNase I hypersensitivity footprints to characterize regions with high numbers of DAP associations. We establish a generalizable definition for high occupancy target (HOT) loci and identify putative driver DAP motifs in HepG2 cells, including HNF4A, SP1, SP5, and ETV4, that are highly prevalent and show sequence conservation at HOT loci. The number of different DAPs associated with an element is positively associated with evidence of regulatory activity, and by systematically mutating 245 HOT loci with a massively parallel mutagenesis assay, we localized regulatory activity to a central core region that depends on the motif sequences of our previously nominated driver DAPs. In sum, this work leverages the increasingly large number of DAP motif and ChIP-seq data publicly available to explore how DAP associations contribute to genome-wide transcriptional regulation.


Assuntos
Elementos Facilitadores Genéticos , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Composição de Bases , Linhagem Celular , Cromatina/química , Sequenciamento de Cromatina por Imunoprecipitação , DNA/química , Loci Gênicos , Genoma , Células Hep G2 , Humanos , Mutagênese , Mutação , Motivos de Nucleotídeos
10.
Am J Hum Genet ; 106(5): 632-645, 2020 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-32330418

RESUMO

We conducted genome sequencing to search for rare variation contributing to early-onset Alzheimer's disease (EOAD) and frontotemporal dementia (FTD). Discovery analysis was conducted on 435 cases and 671 controls of European ancestry. Burden testing for rare variation associated with disease was conducted using filters based on variant rarity (less than one in 10,000 or private), computational prediction of deleteriousness (CADD) (10 or 15 thresholds), and molecular function (protein loss-of-function [LoF] only, coding alteration only, or coding plus non-coding variants in experimentally predicted regulatory regions). Replication analysis was conducted on 16,434 independent cases and 15,587 independent controls. Rare variants in TET2 were enriched in the discovery combined EOAD and FTD cohort (p = 4.6 × 10-8, genome-wide corrected p = 0.0026). Most of these variants were canonical LoF or non-coding in predicted regulatory regions. This enrichment replicated across several cohorts of Alzheimer's disease (AD) and FTD (replication only p = 0.0029). The combined analysis odds ratio was 2.3 (95% confidence interval [CI] 1.6-3.4) for AD and FTD. The odds ratio for qualifying non-coding variants considered independently from coding variants was 3.7 (95% CI 1.7-9.4). For LoF variants, the combined odds ratio (for AD, FTD, and amyotrophic lateral sclerosis, which shares clinicopathological overlap with FTD) was 3.1 (95% CI 1.9-5.2). TET2 catalyzes DNA demethylation. Given well-defined changes in DNA methylation that occur during aging, rare variation in TET2 may confer risk for neurodegeneration by altering the homeostasis of key aging-related processes. Additionally, our study emphasizes the relevance of non-coding variation in genetic studies of complex disease.


Assuntos
Proteínas de Ligação a DNA/deficiência , Proteínas de Ligação a DNA/genética , Mutação com Perda de Função/genética , Doenças Neurodegenerativas/genética , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Animais , Cognição , Dioxigenases , Feminino , Demência Frontotemporal/genética , Humanos , Masculino , Camundongos
11.
Breast Cancer Res ; 22(1): 22, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32070401

RESUMO

BACKGROUND: In preclinical studies, the expression of vascular endothelial growth factor (VEGF) in hormone receptor-positive breast cancer is associated with estrogen-independent tumor growth and resistance to endocrine therapies. This study investigated whether the addition of bevacizumab, a monoclonal antibody against VEGF, to letrozole enhanced the antitumor activity of the letrozole in the preoperative setting. METHODS: Postmenopausal women with newly diagnosed stage 2 or 3 estrogen and/or progesterone receptor-positive, HER2-negative breast cancer were randomly assigned (2:1) between letrozole 2.5 mg PO daily plus bevacizumab 15 mg/kg IV every 3 weeks (Let/Bev) and letrozole 2.5 mg PO daily (Let) for 24 weeks prior to definitive surgery. Primary objective was within-arm pathologic complete remission (pCR) rate. Secondary objectives were safety, objective response, and downstaging rate. RESULTS: Seventy-five patients were randomized (Let/Bev n = 50, Let n = 25). Of the 45 patients evaluable for pathological response in the Let/Bev arm, 5 (11%; 95% CI, 3.7-24.1%) achieved pCR and 4 (9%; 95% CI, 2.5-21.2%) had microscopic residual disease; no pCRs or microscopic residual disease was seen in the Let arm (0%; 95% CI, 0-14.2%). The rates of downstaging were 44.4% (95% CI, 29.6-60.0%) and 37.5% (95% CI, 18.8-59.4%) in the Let/Bev and Let arms, respectively. Adverse events typically associated with letrozole (hot flashes, arthralgias, fatigue, myalgias) occurred in similar frequencies in the two arms. Hypertension, headache, and proteinuria were seen exclusively in the Let/Bev arm. The rates of grade 3 and 4 adverse events and discontinuation due to adverse events were 18% vs 8% and 16% vs none in the Let/Bev and Let arms, respectively. A small RNA-based classifier predictive of response to preoperative Let/Bev was developed and confirmed on an independent cohort. CONCLUSION: In the preoperative setting, the addition of bevacizumab to letrozole was associated with a pCR rate of 11%; no pCR was seen with letrozole alone. There was additive toxicity with the incorporation of bevacizumab. Responses to Let/Bev can be predicted from the levels of 5 small RNAs in a pretreatment biopsy. TRIAL REGISTRATION: This trial is registered with ClinicalTrials.gov (Identifier: NCT00161291), first posted on September 12, 2005, and is completed.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Neoplasias Hormônio-Dependentes/tratamento farmacológico , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/metabolismo , Idoso , Idoso de 80 Anos ou mais , Bevacizumab/administração & dosagem , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Letrozol/administração & dosagem , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Hormônio-Dependentes/genética , Neoplasias Hormônio-Dependentes/metabolismo , Neoplasias Hormônio-Dependentes/patologia , Pós-Menopausa , Receptor ErbB-2/metabolismo , Transcriptoma
12.
Methods Mol Biol ; 2117: 3-34, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31960370

RESUMO

Chromatin immunoprecipitation followed by next-generation DNA sequencing (ChIP-seq) has been used to identify transcription factor (TF) binding proteins throughout the genome. Unfortunately, this approach traditionally requires commercially available, ChIP-seq grade antibodies that frequently fail to generate acceptable datasets. To obtain data for the many TFs for which there is no appropriate antibody, we recently developed a new method for performing ChIP-seq by epitope tagging endogenous TFs using CRISPR/Cas9 genome editing technology (CETCh-seq). Here, we describe our general protocol of CETCh-seq for both adherent and nonadherent cell lines using a commercially available FLAG antibody.


Assuntos
Epitopos/metabolismo , Fatores de Transcrição/análise , Fatores de Transcrição/genética , Sítios de Ligação , Sistemas CRISPR-Cas , Adesão Celular , Sequenciamento de Cromatina por Imunoprecipitação , Edição de Genes , Células Hep G2 , Humanos , Ligação Proteica
13.
Cell Rep ; 29(5): 1203-1220.e7, 2019 10 29.
Artigo em Inglês | MEDLINE | ID: mdl-31665634

RESUMO

The basic leucine zipper transcription factor activating transcription factor-like (Batf) contributes to transcriptional programming of multiple effector T cells and is required for T helper 17 (Th17) and T follicular helper (Tfh) cell development. Here, we examine mechanisms by which Batf initiates gene transcription in developing effector CD4 T cells. We find that, in addition to its pioneering function, Batf controls developmentally regulated recruitment of the architectural factor Ctcf to promote chromatin looping that is associated with lineage-specific gene transcription. The chromatin-organizing actions of Batf are largely dependent on Ets1, which appears to be indispensable for the Batf-dependent recruitment of Ctcf. Moreover, most of the Batf-dependent sites to which Ctcf is recruited lie outside of activating protein-1-interferon regulatory factor (Ap-1-Irf) composite elements (AICEs), indicating that direct involvement of Batf-Irf complexes is not required. These results identify a cooperative role for Batf, Ets1, and Ctcf in chromatin reorganization that underpins the transcriptional programming of effector T cells.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Fator de Ligação a CCCTC/metabolismo , Linfócitos T CD4-Positivos/metabolismo , Cromatina/metabolismo , Proteína Proto-Oncogênica c-ets-1/metabolismo , Animais , Montagem e Desmontagem da Cromatina , Genoma , Humanos , Fatores Reguladores de Interferon/metabolismo , Interleucinas/metabolismo , Ativação Linfocitária/imunologia , Camundongos Endogâmicos C57BL , Ligação Proteica , Regulação para Cima/genética
14.
iScience ; 17: 167-181, 2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31279934

RESUMO

The erythropoietin receptor (EPOR) plays an essential role in erythropoiesis and other cellular processes by forming distinct signaling complexes composed of EPOR homodimers or hetero-oligomers between the EPOR and another receptor, but the mechanism of heteroreceptor assembly and signaling is poorly understood. We report here a 46-residue, artificial transmembrane protein aptamer, designated ELI-3, that binds and activates the EPOR and induces growth factor independence in murine BaF3 cells expressing the EPOR. ELI-3 requires the transmembrane domain and JAK2-binding sites of the EPOR for activity, but not the cytoplasmic tyrosines that mediate canonical EPOR signaling. Instead, ELI-3-induced proliferation and activation of JAK/STAT signaling requires the transmembrane and cytoplasmic domains of the cytokine receptor ß-common subunit (ßcR) in addition to the EPOR. Moreover, ELI-3 fails to induce erythroid differentiation of primary human hematopoietic progenitor cells but inhibits nonhematopoietic cell death induced by serum withdrawal.

15.
EBioMedicine ; 44: 209-224, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31160272

RESUMO

BACKGROUND: Administration of amplitude modulated 27·12 MHz radiofrequency electromagnetic fields (AM RF EMF) by means of a spoon-shaped applicator placed on the patient's tongue is a newly approved treatment for advanced hepatocellular carcinoma (HCC). The mechanism of action of tumour-specific AM RF EMF is largely unknown. METHODS: Whole body and organ-specific human dosimetry analyses were performed. Mice carrying human HCC xenografts were exposed to AM RF EMF using a small animal AM RF EMF exposure system replicating human dosimetry and exposure time. We performed histological analysis of tumours following exposure to AM RF EMF. Using an agnostic genomic approach, we characterized the mechanism of action of AM RF EMF. FINDINGS: Intrabuccal administration results in systemic delivery of athermal AM RF EMF from head to toe at levels lower than those generated by cell phones held close to the body. Tumour shrinkage results from differentiation of HCC cells into quiescent cells with spindle morphology. AM RF EMF targeted antiproliferative effects and cancer stem cell inhibiting effects are mediated by Ca2+ influx through Cav3·2 T-type voltage-gated calcium channels (CACNA1H) resulting in increased intracellular calcium concentration within HCC cells only. INTERPRETATION: Intrabuccally-administered AM RF EMF is a systemic therapy that selectively block the growth of HCC cells. AM RF EMF pronounced inhibitory effects on cancer stem cells may explain the exceptionally long responses observed in several patients with advanced HCC. FUND: Research reported in this publication was supported by the National Cancer Institute's Cancer Centre Support Grant award number P30CA012197 issued to the Wake Forest Baptist Comprehensive Cancer Centre (BP) and by funds from the Charles L. Spurr Professorship Fund (BP). DWG is supported by R01 AA016852 and P50 AA026117.


Assuntos
Canais de Cálcio Tipo T/metabolismo , Cálcio/metabolismo , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/terapia , Magnetoterapia , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Carcinoma Hepatocelular/patologia , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/patologia , Magnetoterapia/métodos , Camundongos , Células-Tronco Neoplásicas/metabolismo , Especificidade de Órgãos , RNA Interferente Pequeno/genética , Radiometria , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Genome Res ; 29(5): 809-818, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30940688

RESUMO

Large-scale sequencing efforts in amyotrophic lateral sclerosis (ALS) have implicated novel genes using gene-based collapsing methods. However, pathogenic mutations may be concentrated in specific genic regions. To address this, we developed two collapsing strategies: One focuses rare variation collapsing on homology-based protein domains as the unit for collapsing, and the other is a gene-level approach that, unlike standard methods, leverages existing evidence of purifying selection against missense variation on said domains. The application of these two collapsing methods to 3093 ALS cases and 8186 controls of European ancestry, and also 3239 cases and 11,808 controls of diversified populations, pinpoints risk regions of ALS genes, including SOD1, NEK1, TARDBP, and FUS While not clearly implicating novel ALS genes, the new analyses not only pinpoint risk regions in known genes but also highlight candidate genes as well.


Assuntos
Esclerose Lateral Amiotrófica/genética , Análise Mutacional de DNA/métodos , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Feminino , Variação Genética , Humanos , Masculino , Mutação , Quinase 1 Relacionada a NIMA/genética , Domínios Proteicos/genética , Proteína FUS de Ligação a RNA/genética , Fatores de Risco , Superóxido Dismutase-1/genética , População Branca/genética , Sequenciamento do Exoma/métodos
17.
iScience ; 13: 43-54, 2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30818224

RESUMO

Histone deacetylases (HDACs) are promising targets for cancer therapy, although their individual actions remain incompletely understood. Here, we identify a role for HDAC2 in the regulation of MDM2 acetylation at previously uncharacterized lysines. Upon inactivation of HDAC2, this acetylation creates a structural signal in the lysine-rich domain of MDM2 to prevent the recognition and degradation of its downstream substrate, MCL-1 ubiquitin ligase E3 (MULE). This mechanism further reveals a therapeutic connection between the MULE ubiquitin ligase function and tumor suppression. Specifically, we show that HDAC inhibitor treatment promotes the accumulation of MULE, which diminishes the t(X; 18) translocation-associated synovial sarcomagenesis by directly targeting the fusion product SS18-SSX for degradation. These results uncover a new HDAC2-dependent pathway that integrates reversible acetylation signaling to the anticancer ubiquitin response.

18.
PLoS Genet ; 14(11): e1007671, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30500825

RESUMO

Mutations that alter signaling of RAS/MAPK-family proteins give rise to a group of Mendelian diseases known as RASopathies. However, among RASopathies, the matrix of genotype-phenotype relationships is still incomplete, in part because there are many RAS-related proteins and in part because the phenotypic consequences may be variable and/or pleiotropic. Here, we describe a cohort of ten cases, drawn from six clinical sites and over 16,000 sequenced probands, with de novo protein-altering variation in RALA, a RAS-like small GTPase. All probands present with speech and motor delays, and most have intellectual disability, low weight, short stature, and facial dysmorphism. The observed rate of de novo RALA variants in affected probands is significantly higher (p = 4.93 x 10(-11)) than expected from the estimated random mutation rate. Further, all de novo variants described here affect residues within the GTP/GDP-binding region of RALA; in fact, six alleles arose at only two codons, Val25 and Lys128. The affected residues are highly conserved across both RAL- and RAS-family genes, are devoid of variation in large human population datasets, and several are homologous to positions at which disease-associated variants have been observed in other GTPase genes. We directly assayed GTP hydrolysis and RALA effector-protein binding of the observed variants, and found that all but one tested variant significantly reduced both activities compared to wild-type. The one exception, S157A, reduced GTP hydrolysis but significantly increased RALA-effector binding, an observation similar to that seen for oncogenic RAS variants. These results show the power of data sharing for the interpretation and analysis of rare variation, expand the spectrum of molecular causes of developmental disability to include RALA, and provide additional insight into the pathogenesis of human disease caused by mutations in small GTPases.


Assuntos
Deficiências do Desenvolvimento/genética , Deficiência Intelectual/genética , Proteínas Mitocondriais/genética , Mutação , Domínios e Motivos de Interação entre Proteínas/genética , Proteínas ral de Ligação ao GTP/genética , Proteínas ras/genética , Fácies , Genótipo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Humanos , Proteínas Mitocondriais/química , Modelos Moleculares , Mutação de Sentido Incorreto , Fenótipo , Conformação Proteica , Proteínas ral de Ligação ao GTP/química , Proteínas ras/química
19.
PLoS Comput Biol ; 14(11): e1006571, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30485278

RESUMO

Sequencing of the T cell receptor (TCR) repertoire is a powerful tool for deeper study of immune response, but the unique structure of this type of data makes its meaningful quantification challenging. We introduce a new method, the Gamma-GPD spliced threshold model, to address this difficulty. This biologically interpretable model captures the distribution of the TCR repertoire, demonstrates stability across varying sequencing depths, and permits comparative analysis across any number of sampled individuals. We apply our method to several datasets and obtain insights regarding the differentiating features in the T cell receptor repertoire among sampled individuals across conditions. We have implemented our method in the open-source R package powerTCR.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sistema Imunitário , Receptores de Antígenos de Linfócitos T/genética , Processamento Alternativo , Animais , Neoplasias Encefálicas/metabolismo , Linfócitos T CD4-Positivos/citologia , Células Clonais , Análise por Conglomerados , Simulação por Computador , Glioblastoma/metabolismo , Humanos , Funções Verossimilhança , Pulmão/metabolismo , Camundongos , Linguagens de Programação , Receptores de Antígenos de Linfócitos T/química , Sarcoidose/metabolismo , Software
20.
Nat Commun ; 9(1): 3594, 2018 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-30185805

RESUMO

The inheritance of gene expression patterns is dependent on epigenetic regulation, but the establishment and maintenance of epigenetic landscapes during T cell differentiation are incompletely understood. Here we show that two stage-specific Cd4 cis-elements, the previously characterized enhancer E4p and a novel enhancer E4m, coordinately promote Cd4 transcription in mature thymic MHC-II-specific T cells, in part through the canonical Wnt pathway. Specifically, E4p licenses E4m to orchestrate DNA demethylation by TET1 and TET3, which in turn poises the Cd4 locus for transcription in peripheral T cells. Cd4 locus demethylation is important for subsequent Cd4 transcription in activated peripheral T cells wherein these cis-elements become dispensable. By contrast, in developing thymocytes the loss of TET1/3 does not affect Cd4 transcription, highlighting an uncoupled event between transcription and epigenetic modifications. Together our findings reveal an important function for thymic cis-elements in governing gene expression in the periphery via a heritable epigenetic mechanism.


Assuntos
Antígenos CD4/genética , Linfócitos T CD4-Positivos/fisiologia , Elementos Facilitadores Genéticos/fisiologia , Epigênese Genética/fisiologia , Regulação da Expressão Gênica/fisiologia , Animais , Antígenos CD4/metabolismo , Diferenciação Celular/genética , Quimera , Desmetilação do DNA , Metilação de DNA/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Dioxigenases , Feminino , Técnicas de Inativação de Genes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Timo/citologia , Timo/fisiologia
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