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1.
Immunity ; 54(5): 931-946.e11, 2021 05 11.
Artículo en Inglés | MEDLINE | ID: mdl-33838102

RESUMEN

Activation of the STAT5 transcription factor downstream of the Interleukin-2 receptor (IL-2R) induces expression of Foxp3, a critical step in the differentiation of regulatory T (Treg) cells. Due to the pleiotropic effects of IL-2R signaling, it is unclear how STAT5 acts directly on the Foxp3 locus to promote its expression. Here, we report that IL-2 - STAT5 signaling converged on an enhancer (CNS0) during Foxp3 induction. CNS0 facilitated the IL-2 dependent CD25+Foxp3- precursor to Treg cell transition in the thymus. Its deficiency resulted in impaired Treg cell generation in neonates, which was partially mitigated with age. While the thymic Treg cell paucity caused by CNS0 deficiency did not result in autoimmunity on its own, it exacerbated autoimmune manifestations caused by disruption of the Aire gene. Thus, CNS0 enhancer activity ensures robust Treg cell differentiation early in postnatal life and cooperatively with other tolerance mechanisms minimizes autoimmunity.


Asunto(s)
Linaje de la Célula/inmunología , Factores de Transcripción Forkhead/inmunología , Tolerancia Inmunológica/inmunología , Interleucina-2/inmunología , Linfocitos T Reguladores/inmunología , Animales , Autoinmunidad/inmunología , Diferenciación Celular/inmunología , Elementos de Facilitación Genéticos/inmunología , Femenino , Humanos , Subunidad alfa del Receptor de Interleucina-2/inmunología , Masculino , Ratones , Receptores de Interleucina-2/inmunología , Factor de Transcripción STAT5/inmunología , Transducción de Señal/inmunología
2.
Mol Cell ; 82(13): 2472-2489.e8, 2022 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-35537449

RESUMEN

Disruption of antagonism between SWI/SNF chromatin remodelers and polycomb repressor complexes drives the formation of numerous cancer types. Recently, an inhibitor of the polycomb protein EZH2 was approved for the treatment of a sarcoma mutant in the SWI/SNF subunit SMARCB1, but resistance occurs. Here, we performed CRISPR screens in SMARCB1-mutant rhabdoid tumor cells to identify genetic contributors to SWI/SNF-polycomb antagonism and potential resistance mechanisms. We found that loss of the H3K36 methyltransferase NSD1 caused resistance to EZH2 inhibition. We show that NSD1 antagonizes polycomb via cooperation with SWI/SNF and identify co-occurrence of NSD1 inactivation in SWI/SNF-defective cancers, indicating in vivo relevance. We demonstrate that H3K36me2 itself has an essential role in the activation of polycomb target genes as inhibition of the H3K36me2 demethylase KDM2A restores the efficacy of EZH2 inhibition in SWI/SNF-deficient cells lacking NSD1. Together our data expand the mechanistic understanding of SWI/SNF and polycomb interplay and identify NSD1 as the key for coordinating this transcriptional control.


Asunto(s)
Proteína Potenciadora del Homólogo Zeste 2 , Proteínas F-Box , N-Metiltransferasa de Histona-Lisina , Histona Demetilasas con Dominio de Jumonji , Proteínas del Grupo Polycomb , Proteína SMARCB1 , Cromatina/genética , Cromatina/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , N-Metiltransferasa de Histona-Lisina/genética , N-Metiltransferasa de Histona-Lisina/metabolismo , Histonas/genética , Histonas/metabolismo , Humanos , Histona Demetilasas con Dominio de Jumonji/genética , Histona Demetilasas con Dominio de Jumonji/metabolismo , Proteínas del Grupo Polycomb/genética , Proteínas del Grupo Polycomb/metabolismo , Tumor Rabdoide/genética , Tumor Rabdoide/metabolismo , Tumor Rabdoide/patología , Proteína SMARCB1/genética , Proteína SMARCB1/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Activación Transcripcional/genética , Células Tumorales Cultivadas/metabolismo
3.
Genes Dev ; 34(1-2): 37-52, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31831628

RESUMEN

In animals, the brain regulates feeding behavior in response to local energy demands of peripheral tissues, which secrete orexigenic and anorexigenic hormones. Although skeletal muscle is a key peripheral tissue, it remains unknown whether muscle-secreted hormones regulate feeding. In Drosophila, we found that decapentaplegic (dpp), the homolog of human bone morphogenetic proteins BMP2 and BMP4, is a muscle-secreted factor (a myokine) that is induced by nutrient sensing and that circulates and signals to the brain. Muscle-restricted dpp RNAi promotes foraging and feeding initiation, whereas dpp overexpression reduces it. This regulation of feeding by muscle-derived Dpp stems from modulation of brain tyrosine hydroxylase (TH) expression and dopamine biosynthesis. Consistently, Dpp receptor signaling in dopaminergic neurons regulates TH expression and feeding initiation via the downstream transcriptional repressor Schnurri. Moreover, pharmacologic modulation of TH activity rescues the changes in feeding initiation due to modulation of dpp expression in muscle. These findings indicate that muscle-to-brain endocrine signaling mediated by the myokine Dpp regulates feeding behavior.


Asunto(s)
Proteínas de Drosophila/metabolismo , Drosophila/genética , Drosophila/metabolismo , Conducta Alimentaria/fisiología , Animales , Encéfalo/fisiología , Proteínas de Unión al ADN/metabolismo , Dopaminérgicos/farmacología , Neuronas Dopaminérgicas/efectos de los fármacos , Neuronas Dopaminérgicas/fisiología , Drosophila/enzimología , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Levodopa/farmacología , Monoyodotirosina/farmacología , Transducción de Señal , Factores de Transcripción/metabolismo , Tirosina 3-Monooxigenasa/genética , Regulación hacia Arriba
4.
EMBO J ; 41(6): e108544, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-34850409

RESUMEN

Since numerous RNAs and RBPs prevalently localize to active chromatin regions, many RNA-binding proteins (RBPs) may be potential transcriptional regulators. RBPs are generally thought to regulate transcription via noncoding RNAs. Here, we describe a distinct, dual mechanism of transcriptional regulation by the previously uncharacterized tRNA-modifying enzyme, hTrmt13. On one hand, hTrmt13 acts in the cytoplasm to catalyze 2'-O-methylation of tRNAs, thus regulating translation in a manner depending on its tRNA-modification activity. On the other hand, nucleus-localized hTrmt13 directly binds DNA as a transcriptional co-activator of key epithelial-mesenchymal transition factors, thereby promoting cell migration independent of tRNA-modification activity. These dual functions of hTrmt13 are mutually exclusive, as it can bind either DNA or tRNA through its CHHC zinc finger domain. Finally, we find that hTrmt13 expression is tightly associated with poor prognosis and survival in diverse cancer patients. Our discovery of the noncatalytic roles of an RNA-modifying enzyme provides a new perspective for understanding epitranscriptomic regulation.


Asunto(s)
ARN de Transferencia , ARNt Metiltransferasas , Humanos , Metilación , ARN/metabolismo , Procesamiento Postranscripcional del ARN , ARN de Transferencia/metabolismo , Proteínas de Unión al ARN/genética , Proteínas de Unión al ARN/metabolismo , ARNt Metiltransferasas/genética , ARNt Metiltransferasas/metabolismo
5.
Blood ; 143(7): 619-630, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-37890156

RESUMEN

ABSTRACT: UBTF tandem duplications (UBTF-TDs) have recently emerged as a recurrent alteration in pediatric and adult acute myeloid leukemia (AML). UBTF-TD leukemias are characterized by a poor response to conventional chemotherapy and a transcriptional signature that mirrors NUP98-rearranged and NPM1-mutant AMLs, including HOX-gene dysregulation. However, the mechanism by which UBTF-TD drives leukemogenesis remains unknown. In this study, we investigated the genomic occupancy of UBTF-TD in transformed cord blood CD34+ cells and patient-derived xenograft models. We found that UBTF-TD protein maintained genomic occupancy at ribosomal DNA loci while also occupying genomic targets commonly dysregulated in UBTF-TD myeloid malignancies, such as the HOXA/HOXB gene clusters and MEIS1. These data suggest that UBTF-TD is a gain-of-function alteration that results in mislocalization to genomic loci dysregulated in UBTF-TD leukemias. UBTF-TD also co-occupies key genomic loci with KMT2A and menin, which are known to be key partners involved in HOX-dysregulated leukemias. Using a protein degradation system, we showed that stemness, proliferation, and transcriptional signatures are dependent on sustained UBTF-TD localization to chromatin. Finally, we demonstrate that primary cells from UBTF-TD leukemias are sensitive to the menin inhibitor SNDX-5613, resulting in markedly reduced in vitro and in vivo tumor growth, myeloid differentiation, and abrogation of the UBTF-TD leukemic expression signature. These findings provide a viable therapeutic strategy for patients with this high-risk AML subtype.


Asunto(s)
Proteínas de Homeodominio , Leucemia Mieloide Aguda , Humanos , Niño , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patología , Factores de Transcripción , Proteína 1 del Sitio de Integración Viral Ecotrópica Mieloide/genética
6.
Nucleic Acids Res ; 52(6): 3291-3309, 2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38165050

RESUMEN

The mechanisms by which the relatively conserved spliceosome manages the enormously large number of splicing events that occur in humans (∼200 000 versus ∼300 in yeast) are poorly understood. Here, we show deposition of one RNA modification-N2-methylguanosine (m2G) on the G72 of U6 snRNA (the catalytic center of the spliceosome) promotes efficient pre-mRNA splicing activity in human cells. This modification was identified to be conserved among vertebrates. Further, THUMPD2 was demonstrated as the methyltransferase responsible for U6 m2G72 by explicitly recognizing the U6-specific sequences and structural elements. The knock-out of THUMPD2 eliminated U6 m2G72 and impaired the pre-mRNA splicing activity, resulting in thousands of changed alternative splicing events of endogenous pre-mRNAs in human cells. Notably, the aberrantly spliced pre-mRNA population elicited the nonsense-mediated mRNA decay pathway. We further show that THUMPD2 was associated with age-related macular degeneration and retinal function. Our study thus demonstrates how an RNA epigenetic modification of the major spliceosome regulates global pre-mRNA splicing and impacts physiology and disease.


Asunto(s)
Precursores del ARN , Empalme del ARN , Proteínas de Unión al ARN , Degeneración Retiniana , Animales , Humanos , Metilación , Conformación de Ácido Nucleico , Degeneración Retiniana/metabolismo , Precursores del ARN/genética , Precursores del ARN/metabolismo , Empalme del ARN/genética , ARN Nuclear Pequeño/metabolismo , Saccharomyces cerevisiae/genética , Empalmosomas/genética , Empalmosomas/metabolismo
7.
Proc Natl Acad Sci U S A ; 120(16): e2220134120, 2023 04 18.
Artículo en Inglés | MEDLINE | ID: mdl-37036970

RESUMEN

Bromo- and extra-terminal domain inhibitors (BETi) have exhibited therapeutic activities in many cancers. However, the mechanisms controlling BETi response and resistance are not well understood. We conducted genome-wide loss-of-function CRISPR screens using BETi-treated KMT2A-rearranged (KMT2A-r) cell lines. We revealed that Speckle-type POZ protein (SPOP) gene (Speckle Type BTB/POZ Protein) deficiency caused significant BETi resistance, which was further validated in cell lines and xenograft models. Proteomics analysis and a kinase-vulnerability CRISPR screen indicated that cells treated with BETi are sensitive to GSK3 perturbation. Pharmaceutical inhibition of GSK3 reversed the BETi-resistance phenotype. Based on this observation, a combination therapy regimen inhibiting both BET and GSK3 was developed to impede KMT2A-r leukemia progression in patient-derived xenografts in vivo. Our results revealed molecular mechanisms underlying BETi resistance and a promising combination treatment regimen of ABBV-744 and CHIR-98014 by utilizing unique ex vivo and in vivo KMT2A-r PDX models.


Asunto(s)
Repeticiones Palindrómicas Cortas Agrupadas y Regularmente Espaciadas , Leucemia , Humanos , Glucógeno Sintasa Quinasa 3/metabolismo , Línea Celular Tumoral , Leucemia/tratamiento farmacológico , Leucemia/genética , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas Represoras/metabolismo
8.
Nature ; 576(7787): 471-476, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31827283

RESUMEN

Adoptive cell therapy represents a new paradigm in cancer immunotherapy, but it can be limited by the poor persistence and function of transferred T cells1. Here we use an in vivo pooled CRISPR-Cas9 mutagenesis screening approach to demonstrate that, by targeting REGNASE-1, CD8+ T cells are reprogrammed to long-lived effector cells with extensive accumulation, better persistence and robust effector function in tumours. REGNASE-1-deficient CD8+ T cells show markedly improved therapeutic efficacy against mouse models of melanoma and leukaemia. By using a secondary genome-scale CRISPR-Cas9 screening, we identify BATF as the key target of REGNASE-1 and as a rheostat that shapes antitumour responses. Loss of BATF suppresses the increased accumulation and mitochondrial fitness of REGNASE-1-deficient CD8+ T cells. By contrast, the targeting of additional signalling factors-including PTPN2 and SOCS1-improves the therapeutic efficacy of REGNASE-1-deficient CD8+ T cells. Our findings suggest that T cell persistence and effector function can be coordinated in tumour immunity and point to avenues for improving the efficacy of adoptive cell therapy for cancer.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Inmunoterapia Adoptiva/métodos , Leucemia/inmunología , Leucemia/terapia , Melanoma/inmunología , Melanoma/terapia , Terapia Molecular Dirigida , Ribonucleasas/metabolismo , Animales , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/deficiencia , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Linfocitos T CD8-positivos/citología , Sistemas CRISPR-Cas/genética , Modelos Animales de Enfermedad , Femenino , Eliminación de Gen , Humanos , Leucemia/genética , Leucemia/metabolismo , Linfocitos Infiltrantes de Tumor/inmunología , Linfocitos Infiltrantes de Tumor/metabolismo , Melanoma/genética , Melanoma/metabolismo , Ratones , Mitocondrias/metabolismo , Proteína Tirosina Fosfatasa no Receptora Tipo 2/genética , Proteína Tirosina Fosfatasa no Receptora Tipo 2/metabolismo , Reproducibilidad de los Resultados , Ribonucleasas/deficiencia , Ribonucleasas/genética , Ribonucleasas/inmunología , Proteína 1 Supresora de la Señalización de Citocinas/genética , Proteína 1 Supresora de la Señalización de Citocinas/metabolismo , Microambiente Tumoral/inmunología
9.
Nature ; 565(7737): 101-105, 2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30568299

RESUMEN

A defining feature of adaptive immunity is the development of long-lived memory T cells to curtail infection. Recent studies have identified a unique stem-like T-cell subset amongst exhausted CD8-positive T cells in chronic infection1-3, but it remains unclear whether CD4-positive T-cell subsets with similar features exist in chronic inflammatory conditions. Amongst helper T cells, TH17 cells have prominent roles in autoimmunity and tissue inflammation and are characterized by inherent plasticity4-7, although how such plasticity is regulated is poorly understood. Here we demonstrate that TH17 cells in a mouse model of autoimmune disease are functionally and metabolically heterogeneous; they contain a subset with stemness-associated features but lower anabolic metabolism, and a reciprocal subset with higher metabolic activity that supports transdifferentiation into TH1-like cells. These two TH17-cell subsets are defined by selective expression of the transcription factors TCF-1 and T-bet, and by discrete levels of CD27 expression. We also identify signalling via the kinase complex mTORC1 as a central regulator of TH17-cell fate decisions by coordinating metabolic and transcriptional programmes. TH17 cells with disrupted mTORC1 signalling or anabolic metabolism fail to induce autoimmune neuroinflammation or to develop into TH1-like cells, but instead upregulate TCF-1 expression and acquire stemness-associated features. Single-cell RNA sequencing and experimental validation reveal heterogeneity in fate-mapped TH17 cells, and a developmental arrest in the TH1 transdifferentiation trajectory upon loss of mTORC1 activity or metabolic perturbation. Our results establish that the dichotomy of stemness and effector function underlies the heterogeneous TH17 responses and autoimmune pathogenesis, and point to previously unappreciated metabolic control of plasticity in helper T cells.


Asunto(s)
Transdiferenciación Celular , Células Madre/citología , Células Madre/metabolismo , Células Th17/citología , Células Th17/metabolismo , Animales , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/metabolismo , Enfermedades Autoinmunes/patología , Modelos Animales de Enfermedad , Femenino , Memoria Inmunológica/inmunología , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/patología , Masculino , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Ratones , Proteína Reguladora Asociada a mTOR/deficiencia , Proteína Reguladora Asociada a mTOR/genética , Análisis de Secuencia de ARN , Transducción de Señal , Análisis de la Célula Individual , Células Madre/inmunología , Factor 1 de Transcripción de Linfocitos T/biosíntesis , Factor 1 de Transcripción de Linfocitos T/metabolismo , Proteínas de Dominio T Box/biosíntesis , Proteínas de Dominio T Box/metabolismo , Células Th17/inmunología , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismo
10.
Drug Resist Updat ; 72: 101017, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37988981

RESUMEN

The role of ABCC4, an ATP-binding cassette transporter, in the process of platelet formation, megakaryopoiesis, is unknown. Here, we show that ABCC4 is highly expressed in megakaryocytes (MKs). Mining of public genomic data (ATAC-seq and genome wide chromatin interactions, Hi-C) revealed that key megakaryopoiesis transcription factors (TFs) interacted with ABCC4 regulatory elements and likely accounted for high ABCC4 expression in MKs. Importantly these genomic interactions for ABCC4 ranked higher than for genes with known roles in megakaryopoiesis suggesting a role for ABCC4 in megakaryopoiesis. We then demonstrate that ABCC4 is required for optimal platelet formation as in vitro differentiation of fetal liver derived MKs from Abcc4-/- mice exhibited impaired proplatelet formation and polyploidization, features required for optimal megakaryopoiesis. Likewise, a human megakaryoblastic cell line, MEG-01 showed that acute ABCC4 inhibition markedly suppressed key processes in megakaryopoiesis and that these effects were related to reduced cAMP export and enhanced dissociation of a negative regulator of megakaryopoiesis, protein kinase A (PKA) from ABCC4. PKA activity concomitantly increased after ABCC4 inhibition which was coupled with significantly reduced GATA-1 expression, a TF needed for optimal megakaryopoiesis. Further, ABCC4 protected MKs from 6-mercaptopurine (6-MP) as Abcc4-/- mice show a profound reduction in MKs after 6-MP treatment. In total, our studies show that ABCC4 not only protects the MKs but is also required for maximal platelet production from MKs, suggesting modulation of ABCC4 function might be a potential therapeutic strategy to regulate platelet production.


Asunto(s)
Plaquetas , Megacariocitos , Animales , Humanos , Ratones , Transportadoras de Casetes de Unión a ATP/metabolismo , Plaquetas/metabolismo , Diferenciación Celular , Megacariocitos/metabolismo , Mercaptopurina/farmacología , Mercaptopurina/metabolismo , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/metabolismo
11.
Nature ; 562(7727): 373-379, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30209392

RESUMEN

Mixed phenotype acute leukaemia (MPAL) is a high-risk subtype of leukaemia with myeloid and lymphoid features, limited genetic characterization, and a lack of consensus regarding appropriate therapy. Here we show that the two principal subtypes of MPAL, T/myeloid (T/M) and B/myeloid (B/M), are genetically distinct. Rearrangement of ZNF384 is common in B/M MPAL, and biallelic WT1 alterations are common in T/M MPAL, which shares genomic features with early T-cell precursor acute lymphoblastic leukaemia. We show that the intratumoral immunophenotypic heterogeneity characteristic of MPAL is independent of somatic genetic variation, that founding lesions arise in primitive haematopoietic progenitors, and that individual phenotypic subpopulations can reconstitute the immunophenotypic diversity in vivo. These findings indicate that the cell of origin and founding lesions, rather than an accumulation of distinct genomic alterations, prime tumour cells for lineage promiscuity. Moreover, these findings position MPAL in the spectrum of immature leukaemias and provide a genetically informed framework for future clinical trials of potential treatments for MPAL.


Asunto(s)
Leucemia Bifenotípica Aguda/genética , Leucemia Bifenotípica Aguda/patología , Linaje de la Célula/genética , Análisis Mutacional de ADN , Femenino , Variación Genética/genética , Genoma Humano/genética , Genómica , Humanos , Inmunofenotipificación , Leucemia Bifenotípica Aguda/clasificación , Masculino , Modelos Genéticos , Mutación/genética , Células Madre Neoplásicas/inmunología , Células Madre Neoplásicas/metabolismo , Células Madre Neoplásicas/patología , Fenotipo , Transactivadores/genética
12.
Blood ; 137(2): 155-167, 2021 01 14.
Artículo en Inglés | MEDLINE | ID: mdl-33156908

RESUMEN

The histone mark H3K27me3 and its reader/writer polycomb repressive complex 2 (PRC2) mediate widespread transcriptional repression in stem and progenitor cells. Mechanisms that regulate this activity are critical for hematopoietic development but are poorly understood. Here we show that the E3 ubiquitin ligase F-box only protein 11 (FBXO11) relieves PRC2-mediated repression during erythroid maturation by targeting its newly identified substrate bromo adjacent homology domain-containing 1 (BAHD1), an H3K27me3 reader that recruits transcriptional corepressors. Erythroblasts lacking FBXO11 are developmentally delayed, with reduced expression of maturation-associated genes, most of which harbor bivalent histone marks at their promoters. In FBXO11-/- erythroblasts, these gene promoters bind BAHD1 and fail to recruit the erythroid transcription factor GATA1. The BAHD1 complex interacts physically with PRC2, and depletion of either component restores FBXO11-deficient erythroid gene expression. Our studies identify BAHD1 as a novel effector of PRC2-mediated repression and reveal how a single E3 ubiquitin ligase eliminates PRC2 repression at many developmentally poised bivalent genes during erythropoiesis.


Asunto(s)
Proteínas Cromosómicas no Histona/metabolismo , Eritropoyesis/fisiología , Proteínas F-Box/metabolismo , Regulación de la Expresión Génica/fisiología , Complejo Represivo Polycomb 2/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Línea Celular , Eritroblastos/metabolismo , Humanos , Proteolisis
13.
J Pathol ; 257(5): 579-592, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35342947

RESUMEN

Mesenchymal chondrosarcoma is a rare, high-grade, primitive mesenchymal tumor. It accounts for around 2-10% of all chondrosarcomas and mainly affects adolescents and young adults. We previously described the HEY1-NCOA2 as a recurrent gene fusion in mesenchymal chondrosarcoma, an important breakthrough for characterizing this disease; however, little study had been done to characterize the fusion protein functionally, in large part due to a lack of suitable models for evaluating the impact of HEY1-NCOA2 expression in the appropriate cellular context. We used iPSC-derived mesenchymal stem cells (iPSC-MSCs), which can differentiate into chondrocytes, and generated stable transduced iPSC-MSCs with inducible expression of HEY1-NCOA2 fusion protein, wildtype HEY1 or wildtype NCOA2. We next comprehensively analyzed both the DNA binding properties and transcriptional impact of HEY1-NCOA2 expression by integrating genome-wide chromatin immunoprecipitation sequencing (ChIP-seq) and expression profiling (RNA-seq). We demonstrated that HEY1-NCOA2 fusion protein preferentially binds to promoter regions of canonical HEY1 targets, resulting in transactivation of HEY1 targets, and significantly enhances cell proliferation. Intriguingly, we identified that both PDGFB and PDGFRA were directly targeted and upregulated by HEY1-NCOA2; and the fusion protein, but not wildtype HEY1 or NCOA2, dramatically increased the level of phospho-AKT (Ser473). Our findings provide a rationale for exploring PDGF/PI3K/AKT inhibition in treating mesenchymal chondrosarcoma. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neoplasias Óseas , Condrosarcoma Mesenquimal , Adolescente , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Neoplasias Óseas/genética , Neoplasias Óseas/patología , Carcinogénesis , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Transformación Celular Neoplásica , Condrosarcoma Mesenquimal/genética , Condrosarcoma Mesenquimal/metabolismo , Condrosarcoma Mesenquimal/patología , Fusión Génica , Genómica , Humanos , Coactivador 2 del Receptor Nuclear/genética , Coactivador 2 del Receptor Nuclear/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Adulto Joven
14.
Nature ; 549(7670): 96-100, 2017 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-28854174

RESUMEN

Paediatric solid tumours arise from endodermal, ectodermal, or mesodermal lineages. Although the overall survival of children with solid tumours is 75%, that of children with recurrent disease is below 30%. To capture the complexity and diversity of paediatric solid tumours and establish new models of recurrent disease, here we develop a protocol to produce orthotopic patient-derived xenografts at diagnosis, recurrence, and autopsy. Tumour specimens were received from 168 patients, and 67 orthotopic patient-derived xenografts were established for 12 types of cancer. The origins of the patient-derived xenograft tumours were reflected in their gene-expression profiles and epigenomes. Genomic profiling of the tumours, including detailed clonal analysis, was performed to determine whether the clonal population in the xenograft recapitulated the patient's tumour. We identified several drug vulnerabilities and showed that the combination of a WEE1 inhibitor (AZD1775), irinotecan, and vincristine can lead to complete response in multiple rhabdomyosarcoma orthotopic patient-derived xenografts tumours in vivo.


Asunto(s)
Neoplasias/tratamiento farmacológico , Ensayos Antitumor por Modelo de Xenoinjerto/métodos , Animales , Bortezomib/farmacología , Bortezomib/uso terapéutico , Camptotecina/análogos & derivados , Camptotecina/farmacología , Camptotecina/uso terapéutico , Proteínas de Ciclo Celular/antagonistas & inhibidores , Niño , Células Clonales , Quimioterapia Combinada , Epigénesis Genética , Femenino , Xenoinjertos/efectos de los fármacos , Xenoinjertos/metabolismo , Xenoinjertos/patología , Xenoinjertos/trasplante , Ensayos Analíticos de Alto Rendimiento/métodos , Humanos , Ácidos Hidroxámicos/farmacología , Ácidos Hidroxámicos/uso terapéutico , Indoles/farmacología , Indoles/uso terapéutico , Irinotecán , Ratones , Neoplasias/genética , Proteínas Nucleares/antagonistas & inhibidores , Panobinostat , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Pirazoles/farmacología , Pirazoles/uso terapéutico , Pirimidinas/farmacología , Pirimidinas/uso terapéutico , Pirimidinonas , Rabdomiosarcoma/tratamiento farmacológico , Rabdomiosarcoma/genética , Vincristina/farmacología , Vincristina/uso terapéutico
15.
Genes Dev ; 29(23): 2475-89, 2015 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-26584623

RESUMEN

Metabolic stress and changes in nutrient levels modulate many aspects of skeletal muscle function during aging and disease. Growth factors and cytokines secreted by skeletal muscle, known as myokines, are important signaling factors, but it is largely unknown whether they modulate muscle growth and differentiation in response to nutrients. Here, we found that changes in glucose levels increase the activity of the glucose-responsive transcription factor MLX (Max-like protein X), which promotes and is necessary for myoblast fusion. MLX promotes myogenesis not via an adjustment of glucose metabolism but rather by inducing the expression of several myokines, including insulin-like growth factor 2 (IGF2), whereas RNAi and dominant-negative MLX reduce IGF2 expression and block myogenesis. This phenotype is rescued by conditioned medium from control muscle cells and by recombinant IGF2, which activates the myogenic kinase Akt. Importantly, MLX-null mice display decreased IGF2 induction and diminished muscle regeneration in response to injury, indicating that the myogenic function of MLX is manifested in vivo. Thus, glucose is a signaling molecule that regulates myogenesis and muscle regeneration via MLX/IGF2/Akt signaling.


Asunto(s)
Desarrollo de Músculos/genética , Músculo Esquelético/citología , Proteínas Nucleares/metabolismo , Transducción de Señal , Factores de Transcripción/metabolismo , Acetilación , Animales , Factores de Transcripción Básicos con Cremalleras de Leucinas y Motivos Hélice-Asa-Hélice , Línea Celular , Regulación del Desarrollo de la Expresión Génica/genética , Glucosa/metabolismo , Histonas/metabolismo , Factor II del Crecimiento Similar a la Insulina/genética , Factor II del Crecimiento Similar a la Insulina/metabolismo , Ratones , Ratones Endogámicos C57BL , Músculo Esquelético/fisiología , Regeneración
16.
EMBO Rep ; 21(8): e50095, 2020 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-32558197

RESUMEN

tRNA modifications at the anti-codon loop are critical for accurate decoding. FTSJ1 was hypothesized to be a human tRNA 2'-O-methyltransferase. tRNAPhe (GAA) from intellectual disability patients with mutations in ftsj1 lacks 2'-O-methylation at C32 and G34 (Cm32 and Gm34). However, the catalytic activity, RNA substrates, and pathogenic mechanism of FTSJ1 remain unknown, owing, in part, to the difficulty in reconstituting enzymatic activity in vitro. Here, we identify an interacting protein of FTSJ1, WDR6. For the first time, we reconstitute the 2'-O-methylation activity of the FTSJ1-WDR6 complex in vitro, which occurs at position 34 of specific tRNAs with m1 G37 as a prerequisite. We find that modifications at positions 32, 34, and 37 are interdependent and occur in a hierarchical order in vivo. We also show that the translation efficiency of the UUU codon, but not the UUC codon decoded by tRNAPhe (GAA), is reduced in ftsj1 knockout cells. Bioinformatics analysis reveals that almost 40% of the high TTT-biased genes are related to brain/nervous functions. Our data potentially enhance our understanding of the relationship between FTSJ1 and nervous system development.


Asunto(s)
Discapacidad Intelectual , Codón , Humanos , Discapacidad Intelectual/genética , Metilación , Metiltransferasas/genética , Metiltransferasas/metabolismo , Proteínas Nucleares/metabolismo , ARN de Transferencia/genética , ARN de Transferencia/metabolismo , ARNt Metiltransferasas/genética , ARNt Metiltransferasas/metabolismo
17.
Nucleic Acids Res ; 47(13): 6699-6713, 2019 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-31127282

RESUMEN

Numerous pieces of evidence support the complex, 3D spatial organization of the genome dictates gene expression. CTCF is essential to define topologically associated domain boundaries and to facilitate the formation of insulated chromatin loop structures. To understand CTCF's direct role in global transcriptional regulation, we integrated the miniAID-mClover3 cassette to the endogenous CTCF locus in a human pediatric B-ALL cell line, SEM, and an immortal erythroid precursor cell line, HUDEP-2, to allow for acute depletion of CTCF protein by the auxin-inducible degron system. In SEM cells, CTCF loss notably disrupted intra-TAD loops and TAD integrity in concurrence with a reduction in CTCF-binding affinity, while showing no perturbation to nuclear compartment integrity. Strikingly, the overall effect of CTCF's loss on transcription was minimal. Whole transcriptome analysis showed hundreds of genes differentially expressed in CTCF-depleted cells, among which MYC and a number of MYC target genes were specifically downregulated. Mechanically, acute depletion of CTCF disrupted the direct interaction between the MYC promoter and its distal enhancer cluster residing ∼1.8 Mb downstream. Notably, MYC expression was not profoundly affected upon CTCF loss in HUDEP-2 cells suggesting that CTCF could play a B-ALL cell line specific role in maintaining MYC expression.


Asunto(s)
Factor de Unión a CCCTC/fisiología , Cromatina/ultraestructura , Elementos de Facilitación Genéticos/genética , Regulación Leucémica de la Expresión Génica , Genes myc , Regiones Promotoras Genéticas/genética , Proteínas Proto-Oncogénicas c-myc/biosíntesis , Factor de Unión a CCCTC/deficiencia , Línea Celular Tumoral , Núcleo Celular/metabolismo , Núcleo Celular/ultraestructura , Cromatina/genética , Regulación hacia Abajo , Células Precursoras Eritroides/metabolismo , Técnicas de Sustitución del Gen , Genes Reporteros , Humanos , Conformación de Ácido Nucleico , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Transcriptoma
18.
Int Immunol ; 31(3): 141-156, 2019 03 05.
Artículo en Inglés | MEDLINE | ID: mdl-30407507

RESUMEN

Nuclear hormone receptors including the estrogen receptor (ERα) and the retinoic acid receptor regulate a plethora of biological functions including reproduction, circulation and immunity. To understand how estrogen and other nuclear hormones influence antibody production, we characterized total serum antibody isotypes in female and male mice of C57BL/6J, BALB/cJ and C3H/HeJ mouse strains. Antibody levels were higher in females compared to males in all strains and there was a female preference for IgG2b production. Sex-biased patterns were influenced by vitamin levels, and by antigen specificity toward influenza virus or pneumococcus antigens. To help explain sex biases, we examined the direct effects of estrogen on immunoglobulin heavy chain sterile transcript production among purified, lipopolysaccharide-stimulated B cells. Supplemental estrogen in B-cell cultures significantly increased immunoglobulin heavy chain sterile transcripts. Chromatin immunoprecipitation analyses of activated B cells identified significant ERα binding to estrogen response elements (EREs) centered within enhancer elements of the immunoglobulin heavy chain locus, including the Eµ enhancer and hypersensitive site 1,2 (HS1,2) in the 3' regulatory region. The ERE in HS1,2 was conserved across animal species, and in humans marked a site of polymorphism associated with the estrogen-augmented autoimmune disease, lupus. Taken together, the results highlight: (i) the important targets of ERα in regulatory regions of the immunoglobulin heavy chain locus that influence antibody production, and (ii) the complexity of mechanisms by which estrogen instructs sex-biased antibody production profiles.


Asunto(s)
Formación de Anticuerpos/genética , Elementos de Facilitación Genéticos , Cadenas Pesadas de Inmunoglobulina/genética , Receptores de Estrógenos/metabolismo , Elementos de Respuesta/genética , Caracteres Sexuales , Animales , Formación de Anticuerpos/inmunología , Sitios de Unión , Cadenas Pesadas de Inmunoglobulina/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Elementos de Respuesta/inmunología
19.
Cell Immunol ; 346: 103996, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31703914

RESUMEN

Sex hormones are best known for their influences on reproduction, but they also have profound influences on the immune response. Examples of sex-specific differences include: (i) the relatively poor control of influenza virus infections in males compared to females, (ii) allergic asthma, an IgE-associated hypersensitivity reaction that is exacerbated in adolescent females compared to males, and (iii) systemic lupus erythematosus, a life-threatening autoimmune disease with a 9:1 female:male bias. Here we consider how estrogen and estrogen receptor α (ERα) may influence the immune response by modifying class switch recombination (CSR) and immunoglobulin expression patterns. We focus on ERα binding to enhancers (Eµ and the 3' regulatory region) and switch sites (Sµ and Sε) in the immunoglobulin heavy chain locus. Our preliminary data from ChIP-seq analyses of purified, activated B cells show estrogen-mediated changes in the positioning of ERα binding within and near Sµ and Sε. In the presence of estrogen, ERα is bound not only to estrogen response elements (ERE), but also to adenosine-cytidine (AC)-repeats and poly adenosine (poly A) sequences, in some cases within constant region gene introns. We propose that by binding these sites, estrogen and ERα directly participate in the DNA loop formation required for CSR. We further suggest that estrogen regulates immunoglobulin expression patterns and can thereby influence life-and-death outcomes of infection, hypersensitivity, and autoimmune disease.


Asunto(s)
Receptor alfa de Estrógeno/metabolismo , Estrógenos/metabolismo , Cambio de Clase de Inmunoglobulina/inmunología , Enfermedades Autoinmunes/inmunología , Femenino , Humanos , Hipersensibilidad/genética , Hipersensibilidad/inmunología , Masculino , Poli A/genética , Elementos de Respuesta/genética
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