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1.
Genome Res ; 2018 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-29429977

RESUMEN

High expression of the transcription factor ZFX is correlated with proliferation, tumorigenesis, and patient survival in multiple types of human cancers. However, the mechanism by which ZFX influences transcriptional regulation has not been determined. We performed ChIP-seq in four cancer cell lines (representing kidney, colon, prostate, and breast cancers) to identify ZFX binding sites throughout the human genome. We identified ~9,000 ZFX binding sites and found that the majority of the sites are in CpG island promoters. Moreover, genes with promoters bound by ZFX are expressed at higher levels than genes with promoters not bound by ZFX. To determine if ZFX contributes to regulation of the promoters to which it is bound, we performed RNA-seq analysis after knockdown of ZFX by siRNA in prostate and breast cancer cells. Many genes with promoters bound by ZFX were downregulated upon ZFX knockdown, supporting the hypothesis that ZFX acts as a transcriptional activator. Surprisingly, ZFX binds at +240 bp downstream of the TSS of the responsive promoters. Using Nucleosome Occupancy and Methylome Sequencing (NOMe-seq), we show that ZFX binds between the open chromatin region at the TSS and the first downstream nucleosome, suggesting that ZFX may play a critical role in promoter architecture. We have also shown that a closely related zinc finger protein ZNF711 has a similar binding pattern at CpG island promoters, but ZNF711 may play a subordinate role to ZFX. This functional characterization of ZFX provides important new insights into transcription, chromatin structure, and the regulation of the cancer transcriptome.

2.
J Cell Biochem ; 120(3): 3056-3070, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30548288

RESUMEN

Distal regulatory elements influence the activity of gene promoters through chromatin looping. Chromosome conformation capture (3C) methods permit identification of chromatin contacts across different regions of the genome. However, due to limitations in the resolution of these methods, the detection of functional chromatin interactions remains a challenge. In the current study, we employ an integrated approach to define and characterize the functional chromatin contacts of human pancreatic cancer cells. We applied tethered chromatin capture to define classes of chromatin domains on a genome-wide scale. We identified three types of structural domains (topologically associated, boundary, and gap) and investigated the functional relationships of these domains with respect to chromatin state and gene expression. We uncovered six distinct sub-domains associated with epigenetic states. Interestingly, specific epigenetically active domains are sensitive to treatment with histone acetyltransferase (HAT) inhibitors and decrease in H3K27 acetylation levels. To examine whether the subdomains that change upon drug treatment are functionally linked to transcription factor regulation, we compared TCF7L2 chromatin binding and gene regulation to HAT inhibition. We identified a subset of coding RNA genes that together can stratify pancreatic cancer patients into distinct survival groups. Overall, this study describes a process to evaluate the functional features of chromosome architecture and reveals the impact of epigenetic inhibitors on chromosome architecture and identifies genes that may provide insight into disease outcome.


Asunto(s)
Benzoatos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Cromatina/metabolismo , Redes Reguladoras de Genes , Neoplasias Pancreáticas/genética , Pirazoles/farmacología , Pirimidinonas/farmacología , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Línea Celular Tumoral , Cromatina/química , Cromatina/genética , Ensamble y Desensamble de Cromatina , Mapeo Cromosómico , Epigénesis Genética/efectos de los fármacos , Epigenómica , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Redes Reguladoras de Genes/efectos de los fármacos , Humanos , Nitrobencenos , Neoplasias Pancreáticas/metabolismo , Pirazolonas , Proteína 2 Similar al Factor de Transcripción 7/genética
3.
Genome Res ; 25(4): 467-77, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25747664

RESUMEN

The holistic role of DNA methylation in the organization of the cancer epigenome is not well understood. Here we perform a comprehensive, high-resolution analysis of chromatin structure to compare the landscapes of HCT116 colon cancer cells and a DNA methylation-deficient derivative. The NOMe-seq accessibility assay unexpectedly revealed symmetrical and transcription-independent nucleosomal phasing across active, poised, and inactive genomic elements. DNA methylation abolished this phasing primarily at enhancers and CpG island (CGI) promoters, with little effect on insulators and non-CGI promoters. Abolishment of DNA methylation led to the context-specific reestablishment of the poised and active states of normal colon cells, which were marked in methylation-deficient cells by distinct H3K27 modifications and the presence of either well-phased nucleosomes or nucleosome-depleted regions, respectively. At higher-order genomic scales, we found that long, H3K9me3-marked domains had lower accessibility, consistent with a more compact chromatin structure. Taken together, our results demonstrate the nuanced and context-dependent role of DNA methylation in the functional, multiscale organization of cancer epigenomes.


Asunto(s)
Cromatina/genética , Neoplasias del Colon/genética , Metilación de ADN/genética , Línea Celular Tumoral , Islas de CpG/genética , ADN (Citosina-5-)-Metiltransferasa 1 , ADN (Citosina-5-)-Metiltransferasas/biosíntesis , ADN (Citosina-5-)-Metiltransferasas/genética , Epigénesis Genética , Células HCT116 , Histonas/genética , Humanos , Nucleosomas/genética , Regiones Promotoras Genéticas/genética , ADN Metiltransferasa 3B
4.
Plant J ; 84(1): 216-27, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26252423

RESUMEN

Barley (Hordeum vulgare L.) possesses a large and highly repetitive genome of 5.1 Gb that has hindered the development of a complete sequence. In 2012, the International Barley Sequencing Consortium released a resource integrating whole-genome shotgun sequences with a physical and genetic framework. However, because only 6278 bacterial artificial chromosome (BACs) in the physical map were sequenced, fine structure was limited. To gain access to the gene-containing portion of the barley genome at high resolution, we identified and sequenced 15 622 BACs representing the minimal tiling path of 72 052 physical-mapped gene-bearing BACs. This generated ~1.7 Gb of genomic sequence containing an estimated 2/3 of all Morex barley genes. Exploration of these sequenced BACs revealed that although distal ends of chromosomes contain most of the gene-enriched BACs and are characterized by high recombination rates, there are also gene-dense regions with suppressed recombination. We made use of published map-anchored sequence data from Aegilops tauschii to develop a synteny viewer between barley and the ancestor of the wheat D-genome. Except for some notable inversions, there is a high level of collinearity between the two species. The software HarvEST:Barley provides facile access to BAC sequences and their annotations, along with the barley-Ae. tauschii synteny viewer. These BAC sequences constitute a resource to improve the efficiency of marker development, map-based cloning, and comparative genomics in barley and related crops. Additional knowledge about regions of the barley genome that are gene-dense but low recombination is particularly relevant.


Asunto(s)
Cromosomas Artificiales Bacterianos/genética , Genoma de Planta/genética , Hordeum/genética , Datos de Secuencia Molecular
5.
Nat Methods ; 10(10): 992-5, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23955773

RESUMEN

Variability in the quality of antibodies to histone post-translational modifications (PTMs) is a widely recognized hindrance in epigenetics research. Here, we produced recombinant antibodies to the trimethylated lysine residues of histone H3 with high specificity and affinity and no lot-to-lot variation. These recombinant antibodies performed well in common epigenetics applications, and enabled us to identify positive and negative correlations among histone PTMs.


Asunto(s)
Anticuerpos/inmunología , Afinidad de Anticuerpos , Histonas/inmunología , Lisina/inmunología , Procesamiento Proteico-Postraduccional , Animales , Anticuerpos/genética , Sitios de Unión de Anticuerpos , Línea Celular , Escherichia coli/genética , Histonas/química , Histonas/genética , Humanos , Lisina/química , Lisina/genética , Biblioteca de Péptidos , Sensibilidad y Especificidad , Anticuerpos de Cadena Única/genética , Anticuerpos de Cadena Única/inmunología
6.
Nucleic Acids Res ; 40(16): 7690-704, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22675074

RESUMEN

We have analyzed publicly available K562 Hi-C data, which enable genome-wide unbiased capturing of chromatin interactions, using a Mixture Poisson Regression Model and a power-law decay background to define a highly specific set of interacting genomic regions. We integrated multiple ENCODE Consortium resources with the Hi-C data, using DNase-seq data and ChIP-seq data for 45 transcription factors and 9 histone modifications. We classified 12 different sets (clusters) of interacting loci that can be distinguished by their chromatin modifications and which can be categorized into two types of chromatin linkages. The different clusters of loci display very different relationships with transcription factor-binding sites. As expected, many of the transcription factors show binding patterns specific to clusters composed of interacting loci that encompass promoters or enhancers. However, cluster 9, which is distinguished by marks of open chromatin but not by active enhancer or promoter marks, was not bound by most transcription factors but was highly enriched for three transcription factors (GATA1, GATA2 and c-Jun) and three chromatin modifiers (BRG1, INI1 and SIRT6). To investigate the impact of chromatin organization on gene regulation, we performed ribonucleicacid-seq analyses before and after knockdown of GATA1 or GATA2. We found that knockdown of the GATA factors not only alters the expression of genes having a nearby bound GATA but also affects expression of genes in interacting loci. Our work, in combination with previous studies linking regulation by GATA factors with c-Jun and BRG1, provides genome-wide evidence that Hi-C data identify sets of biologically relevant interacting loci.


Asunto(s)
Cromatina/metabolismo , Regulación de la Expresión Génica , Factores de Transcripción/metabolismo , Sitios de Unión , Cromatina/química , Cromatina/clasificación , Inmunoprecipitación de Cromatina , Análisis por Conglomerados , Epigénesis Genética , Factores de Transcripción GATA/metabolismo , Sitios Genéticos , Genoma Humano , Histonas/metabolismo , Humanos , Células K562 , Análisis de Regresión , Elementos Reguladores de la Transcripción , Análisis de Secuencia de ADN , Análisis de Secuencia de ARN , Integración de Sistemas
7.
J Cross Cult Gerontol ; 27(4): 305-17, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22903533

RESUMEN

This study examines two sources of informal support-perceived family and friend support-and the psychological well-being-self-esteem, depression and loneliness-of 150 Chinese and 145 American elders. There were no significant differences between the elderly American and Chinese persons' mean scores on family and friend support. The multiple linear regression analyses with interaction terms (country x family support and country x friend support), however, indicated that the relationship between family support and depression and family support and loneliness was stronger for the Chinese elderly than the US elderly. Conversely, the relationship between friend support and depression and friend support and loneliness is stronger for US elderly than Chinese elderly. The implications of these findings for social work practice in both countries is discussed.


Asunto(s)
Relaciones Familiares/etnología , Amigos , Soledad/psicología , Satisfacción Personal , Apoyo Social , Anciano , Anciano de 80 o más Años , Pueblo Asiatico/psicología , China , Comparación Transcultural , Estudios Transversales , Depresión/psicología , Femenino , Evaluación Geriátrica , Estado de Salud , Humanos , Entrevistas como Asunto , Masculino , Pennsylvania , Percepción , Escalas de Valoración Psiquiátrica , Calidad de Vida/psicología , Análisis de Regresión , Autoimagen
8.
Soc Work Public Health ; 37(1): 28-32, 2022 01 02.
Artículo en Inglés | MEDLINE | ID: mdl-34431453

RESUMEN

The human rights of transgender and gender non-conforming individuals are under attack at unprecedented levels all over the United States. This article begins by defining and describing human rights and explaining in detail the threats to the human rights and safety of transgender and gender non-conforming individuals. Finally, the article urges ongoing social work engagement in advocating for the protection of those rights by utilizing the policy window created by the Bostock v. Clayton County ruling and recent executive orders issued by the Biden Administration to promote safety for transgender and gender non-conforming community members. The article concludes with suggestions for social workers practitioners and educators.


Asunto(s)
Personas Transgénero , Identidad de Género , Derechos Humanos , Humanos , Servicio Social , Estados Unidos
9.
J Cross Cult Gerontol ; 26(1): 71-83, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21161356

RESUMEN

The purpose of this study is to explore the attitudes older Chinese adults have about engaging in counseling-based services as measured by a fear of intimacy with helping professionals scale. Data were collected from 150 older adults living in Chongqing, China. Information from this study will be helpful in developing effective strategies for the provision of social work services in China. In contrast with previous research, attitudes about intimacy with helping professionals varied and were normally distributed. Significant predictors of fear of intimacy were level of trust, mental health stigma, family support and friend support. Surprisingly, family and friend support had opposite associations with fear of intimacy. Family support was related to higher fear and friend support to lower fear. The cultural implications of these findings for researchers and social workers working with elderly Chinese clients are discussed.


Asunto(s)
Pueblo Asiatico/psicología , Miedo/psicología , Relaciones Interpersonales , Aceptación de la Atención de Salud/etnología , Relaciones Profesional-Paciente , Adulto , Anciano , China , Cultura , Femenino , Humanos , Masculino , Servicios de Salud Mental/estadística & datos numéricos , Aceptación de la Atención de Salud/psicología , Escalas de Valoración Psiquiátrica , Análisis de Regresión , Medio Social , Apoyo Social , Servicio Social , Encuestas y Cuestionarios
10.
Sci Adv ; 4(12): eaav8550, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30555922

RESUMEN

As part of PsychENCODE, we developed a three-dimensional (3D) epigenomic map of primary cultured neuronal cells derived from olfactory neuroepithelium (CNON). We mapped topologically associating domains and high-resolution chromatin interactions using Hi-C and identified regulatory elements using chromatin immunoprecipitation and nucleosome positioning assays. Using epigenomic datasets from biopsies of 63 living individuals, we found that epigenetic marks at distal regulatory elements are more variable than marks at proximal regulatory elements. By integrating genotype and metadata, we identified enhancers that have different levels corresponding to differences in genetic variation, gender, smoking, and schizophrenia. Motif searches revealed that many CNON enhancers are bound by neuronal-related transcription factors. Last, we combined 3D epigenomic maps and gene expression profiles to predict enhancer-target gene interactions on a genome-wide scale. This study not only provides a framework for understanding individual epigenetic variation using a primary cell model system but also contributes valuable data resources for epigenomic studies of neuronal epithelium.


Asunto(s)
Epigénesis Genética , Epigenómica , Regulación de la Expresión Génica , Neuronas Receptoras Olfatorias/metabolismo , Sitios de Unión , Inmunoprecipitación de Cromatina , Mapeo Cromosómico , Biología Computacional/métodos , Elementos de Facilitación Genéticos , Epigenómica/métodos , Perfilación de la Expresión Génica , Variación Genética , Heterocromatina/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Motivos de Nucleótidos , Unión Proteica , Secuencias Reguladoras de Ácidos Nucleicos , Factores de Transcripción/metabolismo , Transcriptoma , Flujo de Trabajo
11.
Genome Biol ; 15(9): 469, 2014 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-25239471

RESUMEN

BACKGROUND: Gene expression is epigenetically regulated by a combination of histone modifications and methylation of CpG dinucleotides in promoters. In normal cells, CpG-rich promoters are typically unmethylated, marked with histone modifications such as H3K4me3, and are highly active. During neoplastic transformation, CpG dinucleotides of CG-rich promoters become aberrantly methylated, corresponding with the removal of active histone modifications and transcriptional silencing. Outside of promoter regions, distal enhancers play a major role in the cell type-specific regulation of gene expression. Enhancers, which function by bringing activating complexes to promoters through chromosomal looping, are also modulated by a combination of DNA methylation and histone modifications. RESULTS: Here we use HCT116 colorectal cancer cells with and without mutations in DNA methyltransferases, the latter of which results in a 95% reduction in global DNA methylation levels. These cells are used to study the relationship between DNA methylation, histone modifications, and gene expression. We find that the loss of DNA methylation is not sufficient to reactivate most of the silenced promoters. In contrast, the removal of DNA methylation results in the activation of a large number of enhancer regions as determined by the acquisition of active histone marks. CONCLUSIONS: Although the transcriptome is largely unaffected by the loss of DNA methylation, we identify two distinct mechanisms resulting in the upregulation of distinct sets of genes. One is a direct result of DNA methylation loss at a set of promoter regions and the other is due to the presence of new intragenic enhancers.


Asunto(s)
Metilación de ADN , Elementos de Facilitación Genéticos , Islas de CpG , Expresión Génica , Regulación Neoplásica de la Expresión Génica , Células HCT116 , Humanos , Intrones , Análisis de Secuencia de ADN
12.
J Evid Based Soc Work ; 9(4): 317-32, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22830935

RESUMEN

In this study the authors examine the reliability and validity of the Fear of Intimacy with Helping Professionals Scale (FIS-HP) with Chinese (N = 150) and American (N = 145) elderly persons. Factor analysis using principal component analysis with a varimax rotation was used to examine the FIS-HP factor structure for both samples. A three factor solution emerged for both samples. The FIS-HP has acceptable internal consistency reliability with both the United States and China samples. Correlation analysis supported five of the six hypotheses related to convergent validity. English and Mandarin versions of the scale are presented.


Asunto(s)
Miedo , Conducta de Ayuda , Relaciones Profesional-Paciente , Psicometría , Servicio Social/organización & administración , Anciano , Anciano de 80 o más Años , China , Comparación Transcultural , Depresión/psicología , Análisis Factorial , Femenino , Estado de Salud , Indicadores de Salud , Humanos , Soledad/psicología , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Autoimagen , Factores Socioeconómicos , Encuestas y Cuestionarios , Estados Unidos
13.
Genome Biol ; 13(9): R52, 2012 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-22951069

RESUMEN

BACKGROUND: The TCF7L2 transcription factor is linked to a variety of human diseases, including type 2 diabetes and cancer. One mechanism by which TCF7L2 could influence expression of genes involved in diverse diseases is by binding to distinct regulatory regions in different tissues. To test this hypothesis, we performed ChIP-seq for TCF7L2 in six human cell lines. RESULTS: We identified 116,000 non-redundant TCF7L2 binding sites, with only 1,864 sites common to the six cell lines. Using ChIP-seq, we showed that many genomic regions that are marked by both H3K4me1 and H3K27Ac are also bound by TCF7L2, suggesting that TCF7L2 plays a critical role in enhancer activity. Bioinformatic analysis of the cell type-specific TCF7L2 binding sites revealed enrichment for multiple transcription factors, including HNF4alpha and FOXA2 motifs in HepG2 cells and the GATA3 motif in MCF7 cells. ChIP-seq analysis revealed that TCF7L2 co-localizes with HNF4alpha and FOXA2 in HepG2 cells and with GATA3 in MCF7 cells. Interestingly, in MCF7 cells the TCF7L2 motif is enriched in most TCF7L2 sites but is not enriched in the sites bound by both GATA3 and TCF7L2. This analysis suggested that GATA3 might tether TCF7L2 to the genome at these sites. To test this hypothesis, we depleted GATA3 in MCF7 cells and showed that TCF7L2 binding was lost at a subset of sites. RNA-seq analysis suggested that TCF7L2 represses transcription when tethered to the genome via GATA3. CONCLUSIONS: Our studies demonstrate a novel relationship between GATA3 and TCF7L2, and reveal important insights into TCF7L2-mediated gene regulation.


Asunto(s)
Factor de Transcripción GATA3/metabolismo , Genoma Humano , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , Transcripción Genética , Sitios de Unión , Línea Celular Tumoral , Elementos de Facilitación Genéticos , Factor de Transcripción GATA3/genética , Células HEK293 , Factor Nuclear 3-beta del Hepatocito/genética , Factor Nuclear 3-beta del Hepatocito/metabolismo , Factor Nuclear 4 del Hepatocito/genética , Factor Nuclear 4 del Hepatocito/metabolismo , Humanos , Motivos de Nucleótidos , Especificidad de Órganos , Unión Proteica , Proteína 2 Similar al Factor de Transcripción 7/genética
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