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1.
Cell ; 148(1-2): 84-98, 2012 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-22265404

RESUMO

Higher-order chromosomal organization for transcription regulation is poorly understood in eukaryotes. Using genome-wide Chromatin Interaction Analysis with Paired-End-Tag sequencing (ChIA-PET), we mapped long-range chromatin interactions associated with RNA polymerase II in human cells and uncovered widespread promoter-centered intragenic, extragenic, and intergenic interactions. These interactions further aggregated into higher-order clusters, wherein proximal and distal genes were engaged through promoter-promoter interactions. Most genes with promoter-promoter interactions were active and transcribed cooperatively, and some interacting promoters could influence each other implying combinatorial complexity of transcriptional controls. Comparative analyses of different cell lines showed that cell-specific chromatin interactions could provide structural frameworks for cell-specific transcription, and suggested significant enrichment of enhancer-promoter interactions for cell-specific functions. Furthermore, genetically-identified disease-associated noncoding elements were found to be spatially engaged with corresponding genes through long-range interactions. Overall, our study provides insights into transcription regulation by three-dimensional chromatin interactions for both housekeeping and cell-specific genes in human cells.


Assuntos
Cromatina/metabolismo , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , RNA Polimerase II/metabolismo , Transcrição Gênica , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Elementos Facilitadores Genéticos , Estudo de Associação Genômica Ampla , Humanos
2.
Nucleic Acids Res ; 51(D1): D827-D834, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36243967

RESUMO

Spatial omics is a rapidly evolving approach for exploring tissue microenvironment and cellular networks by integrating spatial knowledge with transcript or protein expression information. However, there is a lack of databases for users to access and analyze spatial omics data. To address this limitation, we developed Aquila, a comprehensive platform for managing and analyzing spatial omics data. Aquila contains 107 datasets from 30 diseases, including 6500+ regions of interest, and 15.7 million cells. The database covers studies from spatial transcriptome and proteome analyses, 2D and 3D experiments, and different technologies. Aquila provides visualization of spatial omics data in multiple formats such as spatial cell distribution, spatial expression and co-localization of markers. Aquila also lets users perform many basic and advanced spatial analyses on any dataset. In addition, users can submit their own spatial omics data for visualization and analysis in a safe and secure environment. Finally, Aquila can be installed as an individual app on a desktop and offers the RESTful API service for power users to access the database. Overall, Aquila provides a detailed insight into transcript and protein expression in tissues from a spatial perspective. Aquila is available at https://aquila.cheunglab.org.


Assuntos
Bases de Dados Genéticas , Genômica , Animais , Bases de Dados Factuais , Proteoma/genética , Proteômica , Transcriptoma/genética
3.
Anal Chem ; 96(2): 668-675, 2024 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-38176010

RESUMO

Lead is a widespread environmental hazard that can adversely affect multiple biological functions. Blood cells are the initial targets that face lead exposure. However, a systematic assessment of lead dynamics in blood cells at single-cell resolution is still absent. Herein, C57BL/6 mice were fed with lead-contaminated food. Peripheral blood was harvested at different days. Extracted red blood cells and leukocytes were stained with 19 metal-conjugated antibodies and analyzed by mass cytometry. We quantified the time-lapse lead levels in 12 major blood cell subpopulations and established the distribution of lead heterogeneity. Our results show that the lead levels in all major blood cell subtypes follow lognormal distributions but with distinctively individual skewness. The lognormal distribution suggests a multiplicative accumulation of lead with stochastic turnover of cells, which allows us to estimate the lead lifespan of different blood cell populations by calculating the distribution skewness. These findings suggest that lead accumulation by single blood cells follows a stochastic multiplicative process.


Assuntos
Chumbo , Longevidade , Animais , Camundongos , Chumbo/toxicidade , Camundongos Endogâmicos C57BL , Leucócitos , Eritrócitos
4.
EMBO Rep ; 23(8): e53468, 2022 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-35785414

RESUMO

Androgen receptor (AR) is a master transcription factor that drives prostate cancer (PCa) development and progression. Alterations in the expression or activity of AR coregulators significantly impact the outcome of the disease. Using a proteomics approach, we identified the tripartite motif-containing 33 (TRIM33) as a novel transcriptional coactivator of AR. We demonstrate that TRIM33 facilitates AR chromatin binding to directly regulate a transcription program that promotes PCa progression. TRIM33 further stabilizes AR by protecting it from Skp2-mediated ubiquitination and proteasomal degradation. We also show that TRIM33 is essential for PCa tumor growth by avoiding cell-cycle arrest and apoptosis, and TRIM33 knockdown sensitizes PCa cells to AR antagonists. In clinical analyses, we find TRIM33 upregulated in multiple PCa patient cohorts. Finally, we uncover an AR-TRIM33-coactivated gene signature highly expressed in PCa tumors and predict disease recurrence. Overall, our results reveal that TRIM33 is an oncogenic AR coactivator in PCa and a potential therapeutic target for PCa treatment.


Assuntos
Neoplasias da Próstata , Receptores Androgênicos , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Recidiva Local de Neoplasia/genética , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Receptores Androgênicos/uso terapêutico , Proteínas Quinases Associadas a Fase S/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
Mol Cell ; 64(1): 176-188, 2016 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-27716482

RESUMO

How deregulation of chromatin modifiers causes malignancies is of general interest. Here, we show that histone H2A T120 is phosphorylated in human cancer cell lines and demonstrate that this phosphorylation is catalyzed by hVRK1. Cyclin D1 was one of ten genes downregulated upon VRK1 knockdown in two different cell lines and showed loss of H2A T120 phosphorylation and increased H2A K119 ubiquitylation of its promoter region, resulting in impaired cell growth. In vitro, H2A T120 phosphorylation and H2A K119 ubiquitylation are mutually inhibitory, suggesting that histone phosphorylation indirectly activates chromatin. Furthermore, expression of a phosphomimetic H2A T120D increased H3 K4 methylation. Finally, both VRK1 and the H2A T120D mutant histone transformed NIH/3T3 cells. These results suggest that histone H2A T120 phosphorylation by hVRK1 causes inappropriate gene expression, including upregulated cyclin D1, which promotes oncogenic transformation.


Assuntos
Transformação Celular Neoplásica/genética , Ciclina D1/genética , Regulação Neoplásica da Expressão Gênica , Histonas/genética , Peptídeos e Proteínas de Sinalização Intracelular/genética , Processamento de Proteína Pós-Traducional , Proteínas Serina-Treonina Quinases/genética , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Cromatina/química , Cromatina/metabolismo , Ciclina D1/metabolismo , Proteínas de Drosophila , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Células HeLa , Histonas/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metilação , Camundongos , Oligopeptídeos/genética , Oligopeptídeos/metabolismo , Fosforilação , Protamina Quinase/genética , Protamina Quinase/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Treonina/metabolismo , Ubiquitinação
6.
J Biol Chem ; 298(11): 102525, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36162509

RESUMO

RNA N6-methyladenosine (m6A) is the most abundant internal mRNA modification and forms part of an epitranscriptomic system that modulates RNA function. m6A is reversibly catalyzed by specific enzymes, and those modifications can be recognized by RNA-binding proteins that in turn regulate biological processes. Although there are many reports demonstrating m6A participation in critical biological functions, this exploration has mainly been conducted through the global KO or knockdown of the writers, erasers, or readers of m6A. Consequently, there is a lack of information about the role of m6A on single transcripts in biological processes, posing a challenge in understanding the biological functions of m6A. Here, we demonstrate a CRISPR/dCas13a-based RNA m6A editors, which can target RNAs using a single or multiple CRISPR RNA array to methylate or demethylate m6A in human 293T cells and mouse embryonic stem cells. We systematically assay its capabilities to enable the targeted rewriting of m6A dynamics, including modulation of circular RNA translation and transcript half-life. Finally, we use the system to specifically modulate m6A levels on the noncoding XIST (X-inactive specific transcript) to modulate X chromosome silencing and activation. The editors described here can be used to explore the roles of m6A in biological processes.


Assuntos
Adenosina , RNA Longo não Codificante , RNA , Animais , Humanos , Camundongos , Adenosina/metabolismo , Regulação da Expressão Gênica , RNA/genética , RNA/metabolismo , RNA Longo não Codificante/genética , Proteínas de Ligação a RNA/metabolismo , Sistemas CRISPR-Cas , Células HEK293 , Células-Tronco Embrionárias Murinas , RNA Circular/genética
7.
Anal Chem ; 95(40): 14998-15007, 2023 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-37767956

RESUMO

Mass cytometry by time-of-flight (CyTOF), a high-dimensional single-cell analysis platform, detects up to 50 biomarkers at single-cell resolution. However, CyTOF analysis of biological samples with a minimal number of available cells or rare cell subsets remains a major technical challenge due to the extensive loss of cells during cell recovery, staining, and acquisition. Here, we introduce a platinum-chimeric carrier cell strategy for mass cytometry profiling of ultratrace cell samples. Cisplatin can rapidly enter broken plasma membranes of dead cells and form a chimeric interaction with cellular proteins, peptides, and amino acids. Thus, 198Pt-cisplatin is adopted to tag carrier cells in the pretreatment stage. We investigated 8 cell lines that are commonly accessible in laboratories for their potential as carrier cells to preserve rare target cells for CyTOF analysis. We designed a panel of 35 protein biomarkers to evaluate the comprehensive single-cell subtype classification capability with or without the carrier cell strategy. We further demonstrated the detection and analysis of as few as 1 × 104 immune cells using our method. The proposed method thus allows CyTOF analysis on precious clinical samples with less abundant cells.

8.
Genome Res ; 29(2): 223-235, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30606742

RESUMO

The aberrant activities of transcription factors such as the androgen receptor (AR) underpin prostate cancer development. While the AR cis-regulation has been extensively studied in prostate cancer, information pertaining to the spatial architecture of the AR transcriptional circuitry remains limited. In this paper, we propose a novel framework to profile long-range chromatin interactions associated with AR and its collaborative transcription factor, erythroblast transformation-specific related gene (ERG), using chromatin interaction analysis by paired-end tag (ChIA-PET). We identified ERG-associated long-range chromatin interactions as a cooperative component in the AR-associated chromatin interactome, acting in concert to achieve coordinated regulation of a subset of AR target genes. Through multifaceted functional data analysis, we found that AR-ERG interaction hub regions are characterized by distinct functional signatures, including bidirectional transcription and cotranscription factor binding. In addition, cancer-associated long noncoding RNAs were found to be connected near protein-coding genes through AR-ERG looping. Finally, we found strong enrichment of prostate cancer genome-wide association study (GWAS) single nucleotide polymorphisms (SNPs) at AR-ERG co-binding sites participating in chromatin interactions and gene regulation, suggesting GWAS target genes identified from chromatin looping data provide more biologically relevant findings than using the nearest gene approach. Taken together, our results revealed an AR-ERG-centric higher-order chromatin structure that drives coordinated gene expression in prostate cancer progression and the identification of potential target genes for therapeutic intervention.


Assuntos
Cromatina/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias da Próstata/genética , Receptores Androgênicos/metabolismo , Transcrição Gênica , Linhagem Celular Tumoral , Cromatina/química , Redes Reguladoras de Genes , Genoma Humano , Humanos , Masculino , Proteínas de Fusão Oncogênica/análise , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/metabolismo , RNA Longo não Codificante/metabolismo , Regulador Transcricional ERG/metabolismo , Regulador Transcricional ERG/fisiologia
9.
Biochem J ; 475(11): 1965-1977, 2018 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-29760237

RESUMO

AP-2 gamma (AP-2γ) is a transcription factor that plays pivotal roles in breast cancer biology. To search for small molecule inhibitors of AP-2γ, we performed a high-throughput fluorescence anisotropy screen and identified a polyoxometalate compound with Wells-Dawson structure K6[P2Mo18O62] (Dawson-POM) that blocks the DNA-binding activity of AP-2γ. We showed that this blocking activity is due to the direct binding of Dawson-POM to AP-2γ. We also provided evidence to show that Dawson-POM decreases AP-2γ-dependent transcription similar to silencing the gene. Finally, we demonstrated that Dawson-POM contains anti-proliferative and pro-apoptotic effects in breast cancer cells. In summary, we identified the first small molecule inhibitor of AP-2γ and showed Dawson-POM-mediated inhibition of AP-2γ as a potential avenue for cancer therapy.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia , Fator de Transcrição AP-2/antagonistas & inibidores , Compostos de Tungstênio/farmacologia , Neoplasias da Mama/genética , Neoplasias da Mama/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Cinética , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo , Fator de Transcrição AP-2/genética , Fator de Transcrição AP-2/metabolismo , Compostos de Tungstênio/química , Compostos de Tungstênio/metabolismo
10.
Carcinogenesis ; 37(7): 701-711, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27207661

RESUMO

Neuroendocrine prostate cancer (NEPC) has a poor prognosis, with a median survival of less than 1 year after diagnosis. Following androgen deprivation therapy, prostate adenocarcinoma cells have been observed to develop an androgen receptor-negative, terminally differentiated and indolent neuroendocrine-like phenotype. However, several molecular events, including interleukin 6 (IL-6) stimulation, in the prostate microenvironment result in the appearance of aggressive, highly proliferative castrate-resistant NEPC. In this study, we examined the mechanistic effects of a natural prenylflavonoid, icaritin (ICT), on neuroendocrine differentiation in IL-6-induced LNCaP cells and NEPC development in the male transgenic adenocarcinoma of the mouse prostate (TRAMP) model. TRAMP mice received daily intraperitoneal injection of ICT or vehicle. ICT induced apoptosis in prostate tumor, suppressed NEPC development and, accordingly, improved overall survival in TRAMP mice. Expression of neuroendocrine markers (synaptophysin) and androgen receptor in TRAMP mice and neuroendocrine-like LNCaP cells were inhibited by ICT. Suppression of neuroendocrine and NEPC development by ICT was associated with dose-dependent inhibitory effects on abnormally elevated IL-6/STAT3 and Aurora kinase A in vitro and in vivo Since ICT demonstrated favorable pharmacokinetic and safety profiles with marked enrichment in prostate tissues, our study provides evidence for the development of prenylflavonoid as a multimodal therapeutic agent against NEPC.


Assuntos
Aurora Quinase A/biossíntese , Carcinoma Neuroendócrino/tratamento farmacológico , Flavonoides/administração & dosagem , Interleucina-6/biossíntese , Neoplasias da Próstata/tratamento farmacológico , Fator de Transcrição STAT3/biossíntese , Animais , Aurora Quinase A/genética , Carcinoma Neuroendócrino/genética , Carcinoma Neuroendócrino/patologia , Diferenciação Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Interleucina-6/genética , Masculino , Camundongos , Camundongos Transgênicos , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Receptores Androgênicos/biossíntese , Receptores Androgênicos/genética , Fator de Transcrição STAT3/genética , Transdução de Sinais , Sinaptofisina/biossíntese , Sinaptofisina/genética , Microambiente Tumoral/efeitos dos fármacos
11.
EMBO J ; 31(12): 2810-23, 2012 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-22531786

RESUMO

Transcriptional corepressors are frequently aberrantly over-expressed in prostate cancers. However, their crosstalk with the Androgen receptor (AR), a key player in prostate cancer development, is unclear. Using ChIP-Seq, we generated extensive global binding maps of AR, ERG, and commonly over-expressed transcriptional corepressors including HDAC1, HDAC2, HDAC3, and EZH2 in prostate cancer cells. Surprisingly, our results revealed that ERG, HDACs, and EZH2 are directly involved in androgen-regulated transcription and wired into an AR centric transcriptional network via a spectrum of distal enhancers and/or proximal promoters. Moreover, we showed that similar to ERG, these corepressors function to mediate repression of AR-induced transcription including cytoskeletal genes that promote epithelial differentiation and inhibit metastasis. Specifically, we demonstrated that the direct suppression of Vinculin expression by ERG, EZH2, and HDACs leads to enhanced invasiveness of prostate cancer cells. Taken together, our results highlight a novel mechanism by which, ERG working together with oncogenic corepressors including HDACs and the polycomb protein, EZH2, could impede epithelial differentiation and contribute to prostate cancer progression, through directly modulating the transcriptional output of AR.


Assuntos
Androgênios/biossíntese , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Neoplasias da Próstata/fisiopatologia , Proteínas Repressoras/metabolismo , Diferenciação Celular , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Células Epiteliais/fisiologia , Humanos , Masculino , Ligação Proteica
12.
Carcinogenesis ; 36(7): 757-68, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25908644

RESUMO

Persistent androgen receptor (AR) signaling is the key driving force behind progression and development of castration-resistant prostate cancer (CRPC). In many patients, AR COOH-terminal truncated splice variants (ARvs) play a critical role in contributing to the resistance against androgen depletion therapy. Unfortunately, clinically used antiandrogens like bicalutamide (BIC) and enzalutamide (MDV), which target the ligand binding domain, have failed to suppress these AR variants. Here, we report for the first time that a natural prenylflavonoid, icaritin (ICT), can co-target both persistent AR and ARvs. ICT was found to inhibit transcription of key AR-regulated genes, such as KLK3 [prostate-specific antigen (PSA)] and ARvs-regulated genes, such as UBE2C and induce apoptosis in AR-positive prostate cancer (PC) cells. Mechanistically, ICT promoted the degradation of both AR and ARvs by binding to arylhydrocarbon-receptor (AhR) to mediate ubiquitin-proteasomal degradation. Therefore, ICT impaired AR transactivation in PC cells. Knockdown of AhR gene restored AR stability and partially prevented ICT-induced growth suppression. In clinically relevant murine models orthotopically implanted with androgen-sensitive and CRPC cells, ICT was able to target AR and ARvs, to inhibit AR signaling and tumor growth with no apparent toxicity. Our results provide a mechanistic framework for the development of ICT, as a novel lead compound for AR-positive PC therapeutics, especially for those bearing AR splice variants.


Assuntos
Antineoplásicos/farmacologia , Flavonoides/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Receptores Androgênicos/metabolismo , Receptores de Hidrocarboneto Arílico/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Linhagem Celular Tumoral/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Calicreínas/genética , Calicreínas/metabolismo , Masculino , Camundongos Endogâmicos NOD , Terapia de Alvo Molecular , Antígeno Prostático Específico/genética , Antígeno Prostático Específico/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Estabilidade Proteica/efeitos dos fármacos , Splicing de RNA , Receptores Androgênicos/genética , Receptores de Hidrocarboneto Arílico/genética , Transdução de Sinais/efeitos dos fármacos , Ubiquitina/metabolismo , Enzimas de Conjugação de Ubiquitina/genética , Enzimas de Conjugação de Ubiquitina/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
13.
Mol Cancer ; 14: 136, 2015 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-26201468

RESUMO

BACKGROUND: Aberrant activation of fibroblast growth factor receptors (FGFRs) deregulates cell proliferation and promotes cell survival, and may predispose to tumorigenesis. Therefore, selective inactivation of FGFRs is an important strategy for cancer therapy. Here as a proof-of-concept study, we developed a FGFR1 neutralizing antisera, IMB-R1, employing a novel strategy aimed at preventing the access of essential heparan sulfate (HS) co-receptors to the heparin-binding domain on FGFR1. METHODS: The mRNA and protein expression level of FGFR1 and other FGFRs were examined in several lines of breast cancer and osteosarcoma cells and corresponding normal cells using Taqman real-time quantitative PCR and Western blot analysis. The specificity of IMB-R1 against FGFR1 was assessed with various ELISA-based approaches and Receptor Tyrosine Kinase array. Proliferation assay and apoptosis analysis were performed to assess the effect of IMB-R1 on cancer cell growth and apoptosis, respectively, in comparison with known FGFR1 inhibitors. The IMB-R1 induced alteration of intracellular signaling and gene expression were analysed using Western blot and microarray approaches. Immunohistochemical staining of FGFR1 using IMB-R1 were carried out in different cancer tissues from clinical patients. Throughout the study, statistical differences were determined by Student's t test where appropriate and reported when a p value was less than 0.05. RESULTS: We demonstrate that IMB-R1 is minimally cross-reactive for other FGFRs, and that it potently and specifically inhibits binding of heparin to FGFR1. Furthermore, IMB-R1 blocks the interaction of FGF2 with FGFR1, the kinase activity of FGFR1 and activation of intracellular FGFR signaling. Cancer cells treated with IMB-R1 displayed impaired FGF2 signaling, were unable to grow and instead underwent apoptosis. IMB-R1-induced cell death correlated with a disruption of antioxidative defense networks and increased expression of several tumor suppressors and apoptotic proteins, including p53. Immunostaining with IMB-R1 was stronger in human cancer tissues in which the FGFR1 gene is amplified. CONCLUSION: Our study suggests that blocking HS interaction with the heparin-binding domains of FGFR1 inhibited cancer cell growth, which can be an attractive strategy to inactivate cancer-related heparin-binding proteins.


Assuntos
Antineoplásicos/farmacologia , Heparina/metabolismo , Domínios e Motivos de Interação entre Proteínas , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Anticorpos Monoclonais/farmacologia , Apoptose/efeitos dos fármacos , Apoptose/genética , Biópsia , Proliferação de Células/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Terapia de Alvo Molecular , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/química , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Transdução de Sinais/efeitos dos fármacos
14.
EMBO J ; 30(13): 2569-81, 2011 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-21572391

RESUMO

Oestrogen receptor α (ERα) is key player in the progression of breast cancer. Recently, the cistrome and interactome of ERα were mapped in breast cancer cells, revealing the importance of spatial organization in oestrogen-mediated transcription. However, the underlying mechanism of this process is unclear. Here, we show that ERα binding sites (ERBS) identified from the Chromatin Interaction Analysis-Paired End DiTag of ERα are enriched for AP-2 motifs. We demonstrate the transcription factor, AP-2γ, which has been implicated in breast cancer oncogenesis, binds to ERBS in a ligand-independent manner. Furthermore, perturbation of AP-2γ expression impaired ERα DNA binding, long-range chromatin interactions, and gene transcription. In genome-wide analyses, we show that a large number of AP-2γ and ERα binding events converge together across the genome. The majority of these shared regions are also occupied by the pioneer factor, FoxA1. Molecular studies indicate there is functional interplay between AP-2γ and FoxA1. Finally, we show that most ERBS associated with long-range chromatin interactions are colocalized with AP-2γ and FoxA1. Together, our results suggest AP-2γ is a novel collaborative factor in ERα-mediated transcription.


Assuntos
Cromatina/metabolismo , Receptor alfa de Estrogênio/fisiologia , Fator de Transcrição AP-2/fisiologia , Transcrição Gênica , Sítios de Ligação/genética , Cromatina/genética , Imunoprecipitação da Cromatina , Análise por Conglomerados , Receptor alfa de Estrogênio/antagonistas & inibidores , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Análise em Microsséries , Modelos Biológicos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/genética , Ligação Proteica/fisiologia , RNA Interferente Pequeno/farmacologia , Elementos de Resposta/genética , Fator de Transcrição AP-2/antagonistas & inibidores , Fator de Transcrição AP-2/genética , Transcrição Gênica/genética , Transcrição Gênica/fisiologia , Células Tumorais Cultivadas
15.
Nature ; 462(7269): 58-64, 2009 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-19890323

RESUMO

Genomes are organized into high-level three-dimensional structures, and DNA elements separated by long genomic distances can in principle interact functionally. Many transcription factors bind to regulatory DNA elements distant from gene promoters. Although distal binding sites have been shown to regulate transcription by long-range chromatin interactions at a few loci, chromatin interactions and their impact on transcription regulation have not been investigated in a genome-wide manner. Here we describe the development of a new strategy, chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) for the de novo detection of global chromatin interactions, with which we have comprehensively mapped the chromatin interaction network bound by oestrogen receptor alpha (ER-alpha) in the human genome. We found that most high-confidence remote ER-alpha-binding sites are anchored at gene promoters through long-range chromatin interactions, suggesting that ER-alpha functions by extensive chromatin looping to bring genes together for coordinated transcriptional regulation. We propose that chromatin interactions constitute a primary mechanism for regulating transcription in mammalian genomes.


Assuntos
Cromatina/genética , Cromatina/metabolismo , Receptor alfa de Estrogênio/metabolismo , Genoma Humano/genética , Sítios de Ligação , Linhagem Celular , Imunoprecipitação da Cromatina , Reagentes de Ligações Cruzadas , Formaldeído , Humanos , Regiões Promotoras Genéticas/genética , Ligação Proteica , Reprodutibilidade dos Testes , Análise de Sequência de DNA , Transcrição Gênica , Ativação Transcricional
16.
Anal Chem ; 86(5): 2361-70, 2014 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-24484401

RESUMO

High throughput screening of small molecular weight (LMW) ligands for protein and sensitive determination of ligand-induced protein stabilization is an important task in drug discovery and in protein structural and functional genomics studies. In this study, gold nanoparticles (AuNPs) and their aggregation property are used to develop a rapid and less equipment intensive assay for screening the interactions between LMW ligands and transcription factors (TFs) and human serum albumin. The assay is based on the fact that the aggregation/discpersion status of AuNPs is very sensitive to the conformation of surrounding proteins, and when a LMW ligand binds to the proteins, it can enhance proteins' salt and thermal stability, and therefore the protective effect on AuNPs from aggregation. Two TFs, i.e. FoxA1 (Forkhead box A1) and AP-2γ (activating enhancer binding protein 2 gamma), and 14 compounds from an NCI compounds library and human serum albumin (HSA) and three known ligands (ibuprofen, warfarin, and phenytoin) are involved to demonstrate the concept and to prove its generality and robustness. With this AuNP method, two strong LMW binders are identified for FoxA1 and AP-2γ; ligand induced protein stabilization is determined. The results have been verified using surface plasmon resonance spectroscopy (SPR) and differential static light scattering (DSLS) techniques. Tryptophan fluorescent measurement is also conducted to provide further information on protein conformational change upon LMW ligand loading as can be observed from AuNPs' UV-vis spectra. FoxA1 and AP-2γ are pivotal in regulating the transcriptional activity of estrogen receptor alpha and controlling the expression of estrogen-responsive breast cancer cells. Identification of drug candidates targeting these two transcription factors could be an alternative in treating breast cancer, in particular those that have become endocrine resistance.


Assuntos
Ouro/química , Nanopartículas Metálicas , Proteínas/química , Floculação , Ligantes , Espectrometria de Fluorescência , Ressonância de Plasmônio de Superfície
17.
Anal Biochem ; 448: 95-104, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24291642

RESUMO

Forkhead box protein 1 (FoxA1) is a member of the forkhead family of winged helix transcription factors that plays pivotal roles in the development and differentiation of multiple organs and in the regulation of estrogen-stimulated genes. Conventional analytical methods-electrophoretic mobility shift assay (EMSA) and fluorescence anisotropy (FA)-as well as a gold nanoparticles (AuNPs)-based assay were used to study DNA binding properties of FoxA1 and ligand interruption of FoxA1-DNA binding. In the AuNPs assay, the distinct ability of protein-DNA complex to protect AuNPs against salt-induced aggregation was exploited to screen sequence selectivity and determine the binding affinity constant based on AuNPs color change and absorbance spectrum shift. Both conventional EMSA and FA and the AuNPs assay suggested that FoxA1 binds to DNA in a core sequence-dependent manner and the flanking sequence also played a role to influence the affinity. The EMSA and AuNPs were found to be more sensitive than FA in differentiation of sequence-dependent affinity. With the addition of a spin filtration step, AuNPs assay has been extended for studying small molecular ligand inhibition of FoxA1-DNA interactions enabling drug screening. The results correlate very well with those obtained using FA.


Assuntos
Sondas de DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Polarização de Fluorescência , Ouro/química , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Nanopartículas Metálicas/química , Sequência de Bases , Sondas de DNA/química , Fator 3-alfa Nuclear de Hepatócito/antagonistas & inibidores , Fator 3-alfa Nuclear de Hepatócito/genética , Humanos , Ligantes , Proteínas Ligantes de Maltose/genética , Proteínas Ligantes de Maltose/metabolismo , Ligação Proteica , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/metabolismo
18.
Annu Rev Physiol ; 72: 191-218, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20148673

RESUMO

Many cellular signaling pathways ultimately control specific patterns of gene expression in the nucleus through a variety of signal-regulated transcription factors (TFs), including nuclear hormone receptors (NRs). The advent of genomic technologies for examining signal-regulated transcriptional responses and TF binding on a genomic scale has dramatically increased our understanding of the cellular programs that control hormonal signaling and gene regulation. Studies of TFs, especially NRs, using genomic approaches have revealed novel and unexpected features of hormone-regulated transcription, and a global view is beginning to emerge. In this review, we discuss the genomic methodologies that have been applied to the study of hormone-regulated gene expression, the results that have been obtained from using them, and the future prospects for these approaches. Given the wealth of information about hormone-dependent gene regulation by NRs, we have focused this review on the knowledge gained from genomic studies of their function.


Assuntos
Regulação da Expressão Gênica/fisiologia , Hormônios/genética , Transdução de Sinais/genética , Animais , Cromatina/fisiologia , Imunoprecipitação da Cromatina , Biologia Computacional , Perfilação da Expressão Gênica , Genômica , Hormônios/fisiologia , Humanos , Receptores Citoplasmáticos e Nucleares/fisiologia , Transdução de Sinais/fisiologia , Fatores de Transcrição
19.
Port J Card Thorac Vasc Surg ; 30(4): 75-79, 2024 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-38345877

RESUMO

INTRODUCTION: Popliteal artery aneurysms (PAA) can be very challenging, especially in cases of very large PAAs, with a minimal number of case reports published in the literature. METHODS: This is a case report of a 68-year-old male patient with hypertension, hyperlipidemia, diabetes, and schizophrenia who was found to have a giant (10x8x6cm) partially thrombosed PAA, treated with interposition polytetrafluoroethylene (PTFE) graft via a posterior approach. RESULTS: Under general anesthesia, the patient was placed in a prone position, and an extended lazy "S" incision was made on the popliteal fossa. After obtaining proximal and distal exposure, the aneurysm sac was skeletonized, preserving the popliteal vein and the tibial nerve. After proximal and distal control was obtained, the patient was systemically heparinized, and the aneurysm sac was opened. Some genicular branches were ligated inside the aneurysm, and part of the aneurysm sac was excised. A 7 mm PTFE graft was used for reconstruction in an end-to-end fashion. Suction drains were placed in the popliteal space, and the fascia and skin were approximated. The patient was discharged home on the 2nd postoperative day on aspirin and statin with ultrasound surveillance. The patient has remained asymptomatic during follow-up with a patent graft. CONCLUSIONS: Open surgical repair constitutes the gold standard of care for huge PAAs to prevent distal thromboembolic events and mass pressure effects from the aneurysm. Documentation of additional experience with open repair of huge PAAs would be beneficial and could help clinical decision-making.


Assuntos
Aneurisma , Aneurisma da Artéria Poplítea , Masculino , Humanos , Idoso , Aneurisma/diagnóstico , Joelho , Extremidade Inferior , Politetrafluoretileno , Artéria Poplítea/diagnóstico por imagem
20.
Heliyon ; 10(6): e28071, 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38524605

RESUMO

To explore the feature of cancer cells and tumor subclones, we analyzed 101,065 single-cell transcriptomes from 12 colorectal cancer (CRC) patients and 92 single cell genomes from one of these patients. We found cancer cells, endothelial cells and stromal cells in tumor tissue expressed much more genes and had stronger cell-cell interactions than their counterparts in normal tissue. We identified copy number variations (CNVs) in each cancer cell and found correlation between gene copy number and expression level in cancer cells at single cell resolution. Analysis of tumor subclones inferred by CNVs showed accumulation of mutations in each tumor subclone along lineage trajectories. We found differentially expressed genes (DEGs) between tumor subclones had two populations: DEGCNV and DEGreg. DEGCNV, showing high CNV-expression correlation and whose expression differences depend on the differences of CNV level, enriched in housekeeping genes and cell adhesion associated genes. DEGreg, showing low CNV-expression correlation and mainly in low CNV variation regions and regions without CNVs, enriched in cytokine signaling genes. Furthermore, cell-cell communication analyses showed that DEGCNV tends to involve in cell-cell contact while DEGreg tends to involve in secreted signaling, which further support that DEGCNV and DEGreg are two regulatorily and functionally distinct categories.

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