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1.
Nat Immunol ; 21(3): 274-286, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32066947

RESUMO

Human immunodeficiency virus 1 (HIV-1) infection is associated with heightened inflammation and excess risk of cardiovascular disease, cancer and other complications. These pathologies persist despite antiretroviral therapy. In two independent cohorts, we found that innate lymphoid cells (ILCs) were depleted in the blood and gut of people with HIV-1, even with effective antiretroviral therapy. ILC depletion was associated with neutrophil infiltration of the gut lamina propria, type 1 interferon activation, increased microbial translocation and natural killer (NK) cell skewing towards an inflammatory state, with chromatin structure and phenotype typical of WNT transcription factor TCF7-dependent memory T cells. Cytokines that are elevated during acute HIV-1 infection reproduced the ILC and NK cell abnormalities ex vivo. These results show that inflammatory cytokines associated with HIV-1 infection irreversibly disrupt ILCs. This results in loss of gut epithelial integrity, microbial translocation and memory NK cells with heightened inflammatory potential, and explains the chronic inflammation in people with HIV-1.


Assuntos
Citocinas/sangue , HIV-1/imunologia , HIV-1/patogenicidade , Imunidade Inata , Células Matadoras Naturais/imunologia , Linfócitos/imunologia , Fator 1 de Transcrição de Linfócitos T/imunologia , Regulação da Expressão Gênica , Infecções por HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/virologia , Homeostase/imunologia , Humanos , Memória Imunológica , Técnicas In Vitro , Inflamação/genética , Inflamação/imunologia , Inflamação/virologia , Fator 1 de Transcrição de Linfócitos T/genética , Via de Sinalização Wnt/imunologia
2.
Dev Biol ; 458(2): 215-227, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31751550

RESUMO

In ascidian embryos, the earliest transcription from the zygotic genome begins between the 8-cell and 16-cell stages. Gata.a, a maternally expressed Gata transcription factor, activates target genes specifically in the animal hemisphere, whereas the complex of ß-catenin and Tcf7 antagonizes the activity of Gata.a and activates target genes specifically in the vegetal hemisphere. Here, we show that genes zygotically expressed at the 16-cell stage have significantly more Gata motifs in their upstream regions. These genes included not only genes with animal hemisphere-specific expression but also genes with vegetal hemisphere-specific expression. On the basis of this finding, we performed knockdown experiments for Gata.a and reporter assays, and found that Gata.a is required for the expression of not only genes with animal hemisphere-specific expression, but also genes with vegetal hemisphere-specific expression. Our data indicated that weak Gata.a activity that cannot induce animal hemisphere-specific expression can allow ß-catenin/Tcf7 targets to be expressed in the vegetal cells. Because genes zygotically expressed at the 32-cell stage also had significantly more Gata motifs in their upstream regions, Gata.a function may not be limited to the genes expressed specifically in the animal or vegetal hemispheres at the 16-cell stage, and Gata.a may play an important role in the earliest transcription of the zygotic genome.


Assuntos
Ciona intestinalis/embriologia , Fatores de Transcrição GATA/metabolismo , Animais , Padronização Corporal/genética , Ciona intestinalis/metabolismo , Embrião de Mamíferos/metabolismo , Embrião não Mamífero/metabolismo , Fatores de Transcrição GATA/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Fator 1 de Transcrição de Linfócitos T/genética , Fator 1 de Transcrição de Linfócitos T/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Genética/genética , Urocordados/embriologia , Zigoto/metabolismo
3.
DNA Cell Biol ; 39(1): 16-24, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31808724

RESUMO

Colorectal cancer (CRC) is a severe risk to public health, and there is growing evidence that alternative splicing (AS) plays a crucial role in cancer. However, the AS biomarkers in CRC are seldom reported. In this study, we perform transcriptome analysis of colorectal samples for cancer-specific AS and transcriptomic alterations. We identify 1577 splice events in 885 genes, enriched in CRC-associated pathways and functions. In parallel, we find 10 splicing factors (SFs) with transcriptome variation or significant differential expression. Based on co-expression and binding motif, we construct an SF-AS regulatory network, revealing the association between cancer-specific AS and aberrant SF. Integrating The Cancer Genome Atlas and published sources, we observed that some recurrent AS is an indicator of poor prognosis. Through further experimental verification, we found that the AS of six genes showed significant differences between the tumor sample and the normal sample, and AS of TCF7, COL12A1, GK, and UBA1 can be used as new potential biomarkers in CRC. Our study provides an important analysis of CRC-associated AS, which could act as a starting point for future functional explorations, the development of biomarkers and AS-based target therapy.


Assuntos
Processamento Alternativo , Biomarcadores Tumorais/genética , Neoplasias Colorretais/genética , Regulação Neoplásica da Expressão Gênica , Transcriptoma/genética , Adulto , Sequência de Bases , Feminino , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Homologia de Sequência do Ácido Nucleico , Fator 1 de Transcrição de Linfócitos T/genética
4.
Trends Immunol ; 40(12): 1149-1162, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31734149

RESUMO

T cell factor-1 (TCF-1), encoded by Tcf7, is a transcription factor and histone deacetylase (HDAC) essential for commitment to both the T cell and the innate lymphoid cell (ILC) lineages in mammals. In this review, we discuss the multifunctional role of TCF-1 in establishing these lineages and the requirement for TCF-1 throughout lineage differentiation and maintenance of lineage stability. We highlight recent reports showing promise for TCF-1 as a novel biomarker to identify recently characterized subsets of exhausted CD8+ T cells that may help to predict patient responses to immune checkpoint blockade (ICB).


Assuntos
Linfócitos T CD8-Positivos/fisiologia , Imunidade/genética , Neoplasias/imunologia , Fator 1 de Transcrição de Linfócitos T/metabolismo , Viroses/imunologia , Animais , Diferenciação Celular , Resistência à Doença , Regulação da Expressão Gênica , Humanos , Camundongos , Fator 1 de Transcrição de Linfócitos T/genética
5.
Immunity ; 51(5): 840-855.e5, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31606264

RESUMO

TCF-1 is a key transcription factor in progenitor exhausted CD8 T cells (Tex). Moreover, this Tex cell subset mediates responses to PD-1 checkpoint pathway blockade. However, the role of the transcription factor TCF-1 in early fate decisions and initial generation of Tex cells is unclear. Single-cell RNA sequencing (scRNA-seq) and lineage tracing identified a TCF-1+Ly108+PD-1+ CD8 T cell population that seeds development of mature Tex cells early during chronic infection. TCF-1 mediated the bifurcation between divergent fates, repressing development of terminal KLRG1Hi effectors while fostering KLRG1Lo Tex precursor cells, and PD-1 stabilized this TCF-1+ Tex precursor cell pool. TCF-1 mediated a T-bet-to-Eomes transcription factor transition in Tex precursors by promoting Eomes expression and drove c-Myb expression that controlled Bcl-2 and survival. These data define a role for TCF-1 in early-fate-bifurcation-driving Tex precursor cells and also identify PD-1 as a protector of this early TCF-1 subset.


Assuntos
Linfócitos T CD8-Positivos/metabolismo , Redes Reguladoras de Genes , Fator 1 de Transcrição de Linfócitos T/metabolismo , Transcrição Genética , Animais , Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Doença Crônica , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Camundongos , Receptor de Morte Celular Programada 1/metabolismo , Fator 1 de Transcrição de Linfócitos T/genética , Viroses/genética , Viroses/imunologia , Viroses/virologia
6.
Int J Mol Sci ; 20(19)2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31561429

RESUMO

Long non-coding RNA (lncRNA) biology is a rapidly growing area of study. Thousands of lncRNAs are implicated as key players in cellular pathways and cancer biology. However, the structure-function relationships of these novel biomolecules are not well understood. Recent structural studies suggest that lncRNAs contain modular structural domains, which play a crucial role in their function. Here, we hypothesized that such structural domains exist in lncTCF7, a conserved lncRNA implicated in the development and progression of several cancers. To understand the structure-function relationship of lncTCF7, we characterized its secondary structure using chemical probing methods. Our model revealed structural domains and conserved regions in lncTCF7. One of the modular domains identified here coincides with a known protein-interacting domain. The model reported herein is, to our knowledge, the first structural model of lncTCF7 and thus will serve to direct future studies that will provide fundamental insights into the function of this lncRNA.


Assuntos
Sequência Conservada , Conformação de Ácido Nucleico , RNA Longo não Codificante/química , RNA Longo não Codificante/genética , Fator 1 de Transcrição de Linfócitos T/genética , Sequência de Bases , Humanos , Dobramento de RNA , RNA Longo não Codificante/isolamento & purificação
7.
Nat Commun ; 10(1): 4182, 2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519911

RESUMO

Myoepithelial cells play key roles in normal mammary gland development and in limiting pre-invasive to invasive breast tumor progression, yet their differentiation and perturbation in ductal carcinoma in situ (DCIS) are poorly understood. Here, we investigated myoepithelial cells in normal breast tissues of BRCA1 and BRCA2 germline mutation carriers and in non-carrier controls, and in sporadic DCIS. We found that in the normal breast of non-carriers, myoepithelial cells frequently co-express the p63 and TCF7 transcription factors and that p63 and TCF7 show overlapping chromatin peaks associated with differentiated myoepithelium-specific genes. In contrast, in normal breast tissues of BRCA1 mutation carriers the frequency of p63+TCF7+ myoepithelial cells is significantly decreased and p63 and TCF7 chromatin peaks do not overlap. These myoepithelial perturbations in normal breast tissues of BRCA1 germline mutation carriers may play a role in their higher risk of breast cancer. The fraction of p63+TCF7+ myoepithelial cells is also significantly decreased in DCIS, which may be associated with invasive progression.


Assuntos
Proteína BRCA1/metabolismo , Proteína BRCA2/metabolismo , Carcinoma Ductal de Mama/metabolismo , Mutação/genética , Animais , Proteína BRCA1/genética , Proteína BRCA2/genética , Carcinoma Ductal de Mama/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Proliferação de Células/fisiologia , Feminino , Imunofluorescência , Mutação em Linhagem Germinativa/genética , Humanos , Imuno-Histoquímica , Camundongos , Fator 1 de Transcrição de Linfócitos T/genética , Fator 1 de Transcrição de Linfócitos T/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas Supressoras de Tumor/metabolismo
8.
EBioMedicine ; 45: 181-191, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31248836

RESUMO

BACKGROUND: Perihilar cholangiocarcinoma (PHCC) is the most common type of cholangiocarcinoma with the worst prognosis. Radical resection of PHCC is difficult; thus, few effective biomarkers or useful molecular profiles for PHCC have been reported in recent years. Therefore, in this study, we aimed to assess biomarkers for PHCC. METHODS: We screened potential biomarkers for PHCC using exome and transcriptome sequencing with PHCC tissues and paired normal tissues. Transcription factor 7 (TCF7) expression was evaluated using quantitative reverse transcription polymerase chain reaction, western blotting, and immunohistochemistry. The correlations between TCF7 and clinicopathological factors were analyzed with Chi-square test, and the prognostic significance of TCF7 was evaluated with univariate and multivariate analyses. The functions of TCF7 and its main effectors in PHCC cells were investigated in vitro and in vivo. FINDINGS: TCF7 expression was upregulated in PHCC and was an unfavorable prognostic biomarker. c-Myc was a main effector of TCF7 in PHCC cells and modulated TCF7-induced proliferation, invasion, and migration. FOS-like antigen 1 (FOSL1) was identified as a downstream target of TCF7 and was required in TCF7-induced PHCC proliferation. Triple-positive expression of TCF7, c-Myc, and FOSL1 predicted a much worse prognosis in patients with PHCC than TCF7 expression alone. INTERPRETATION: Postoperative detection of TCF7, c-Myc, and FOSL1 may be useful for stratifying patients with a high risk of unfavorable prognosis, and suppressing TCF7 or its downstream effectors may be a promising strategy for the treatment of PHCC.


Assuntos
Tumor de Klatskin/genética , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-myc/genética , Fator 1 de Transcrição de Linfócitos T/genética , Idoso , Ductos Biliares Intra-Hepáticos/patologia , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Tumor de Klatskin/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico
9.
Med Sci Monit ; 25: 3957-3963, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31133633

RESUMO

BACKGROUND Transcription factor 7 (TCF7) plays an essential role in Wnt signaling by interacting with ß-catenin. Emerging evidence demonstrates that overexpression of TCF7 promotes progression or correlates with poor progression in several types of cancers, but the functions of TCF7 in gastric cancer (GC) have not been revealed. MATERIAL AND METHODS A total of 168 patients with GC who underwent radical surgeries were collected and regarded as the test cohort. The expression of TCF7 in the 168 patients was detected with immunohistochemistry. Moreover, the mRNA levels of TCF7 in 11 pairs of GC and adjacent tissues were detected with quantitative real-time PCR (qRT-PCR). The correlations between TCF7 and the clinicopathological factors were evaluated with the chi-square test, and the prognostic value of TCF7 in GC was investigated with univariate analysis and multivariate analysis. RESULTS The mRNA levels of TCF7 in GC tissues were significantly higher than in corresponding tumor adjacent tissues. The patients of low TCF7 expression and high TCF7 expression accounted for 76.79% (129/168) and 23.21% (39/168), respectively. In our experiments, TCF7 was significantly associated with positive lymphatic invasion (P=0.022) and metastasis (P<0.001). The high expression of TCF7 was correlated with low survival rates (P=0.012) and was confirmed as an independent prognostic factor (HR=1.92, 95%CI =1.06-3.47, P=0.031) of GC in multivariate analysis. CONCLUSIONS TCF7 expression is correlated with metastasis and is an independent prognostic factor of GC. TCF7 detection of GC could help stratify the patients with high risk and guide precise treatment.


Assuntos
Neoplasias Gástricas/metabolismo , Fator 1 de Transcrição de Linfócitos T/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Risco , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Taxa de Sobrevida , Fator 1 de Transcrição de Linfócitos T/genética , Via de Sinalização Wnt , beta Catenina/metabolismo
10.
Front Immunol ; 10: 169, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30814995

RESUMO

The long-term persistence of viral antigens drives virus-specific CD8 T cell exhaustion during chronic viral infection. Yet exhausted, CD8 T cells are still endowed with certain levels of effector function, by which they can keep viral replication in check in chronic infection. However, the regulatory factors involved in regulating the effector function of exhausted CD8 T cell are largely unknown. Using mouse model of chronic LCMV infection, we found that the deletion of transcription factor TCF-1 in LCMV-specific exhausted CD8 T cells led to the profound reduction in cytokine production and degranulation. Conversely, ectopic expression of TCF-1 or using agonist to activate TCF-1 activities promotes the effector function of exhausted CD8 T cells. Mechanistically, TCF-1 fuels the functionalities of exhausted CD8 T cells by promoting the expression of an array of key effector function-associated transcription regulators, including Foxo1, Zeb2, Id3, and Eomes. These results collectively indicate that targeting TCF-1 mediated transcriptional pathway may represent a promising immunotherapy strategy against chronic viral infections by reinvigorating the effector function of exhausted virus-specific CD8 T cells.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Fator 1 de Transcrição de Linfócitos T/metabolismo , Viroses/etiologia , Viroses/metabolismo , Transferência Adotiva , Animais , Sobrevivência Celular , Doença Crônica , Citocinas/metabolismo , Modelos Animais de Doenças , Expressão Gênica , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/metabolismo , Coriomeningite Linfocítica/terapia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Transgênicos , Fator 1 de Transcrição de Linfócitos T/genética , Quimeras de Transplante , Carga Viral , Viroses/terapia
11.
Nat Immunol ; 20(3): 337-349, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30778251

RESUMO

Stem cells are maintained by transcriptional programs that promote self-renewal and repress differentiation. Here, we found that the transcription factor c-Myb was essential for generating and maintaining stem cells in the CD8+ T cell memory compartment. Following viral infection, CD8+ T cells lacking Myb underwent terminal differentiation and generated fewer stem cell-like central memory cells than did Myb-sufficient T cells. c-Myb acted both as a transcriptional activator of Tcf7 (which encodes the transcription factor Tcf1) to enhance memory development and as a repressor of Zeb2 (which encodes the transcription factor Zeb2) to hinder effector differentiation. Domain-mutagenesis experiments revealed that the transactivation domain of c-Myb was necessary for restraining differentiation, whereas its negative regulatory domain was critical for cell survival. Myb overexpression enhanced CD8+ T cell memory formation, polyfunctionality and recall responses that promoted curative antitumor immunity after adoptive transfer. These findings identify c-Myb as a pivotal regulator of CD8+ T cell stemness and highlight its therapeutic potential.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Memória Imunológica/imunologia , Neoplasias Experimentais/imunologia , Proteínas Proto-Oncogênicas c-myb/imunologia , Células-Tronco/imunologia , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Diferenciação Celular/imunologia , Linhagem Celular Tumoral , Células HEK293 , Humanos , Memória Imunológica/genética , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/metabolismo , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/virologia , Proteínas Proto-Oncogênicas c-myb/genética , Proteínas Proto-Oncogênicas c-myb/metabolismo , Células-Tronco/metabolismo , Células-Tronco/virologia , Fator 1 de Transcrição de Linfócitos T/genética , Fator 1 de Transcrição de Linfócitos T/imunologia , Fator 1 de Transcrição de Linfócitos T/metabolismo
12.
Clin Rheumatol ; 38(3): 933-938, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30238381

RESUMO

The objective was to explore changes in gene expression in Wnt pathway genes in skin samples of black South Africans with diffuse cutaneous systemic sclerosis (dcSSc). Affected (forearm) and unaffected (upper back) skin samples of eight Black South Africans with active early dcSSc were compared to skin samples from seven ethnically matched control subjects. The Wnt Pathway Plus RT2 Profiler qPCR Array was used to determine gene expression and analyzed for differential expression between cases and controls. Selective validation was done using single-gene TaqMan assays. Several genes were similarly upregulated in both affected and unaffected skin of the dcSSc patients compared to controls. These included the Wnt ligands WNT7A and WNT10A, the frizzled receptors FZD8 and FZD9, intracellular signaling proteins AXIN1 and AXIN2, and the pathway target genes FGF4 and MMP7. Principal component analysis revealed patients clustering into two groups, which co-segregated with clinical features of interstitial lung disease and/or inflammatory myopathy, or the absence of an inflammation phenotype. These two groups showed paradoxical gene expression of the genes TCF7, SOX17, and FRZB in affected and unaffected skin. This study provides further evidence of dysregulation of gene expression at various levels of the Wnt signaling pathway in dcSSc. Moreover, principal component analysis showed two distinct patient clusters of gene expression, which co-segregated with the presence or absence of clinical inflammatory features, and may reflect different pathological pathways in dcSSc.


Assuntos
Esclerodermia Difusa/genética , Pele/metabolismo , Via de Sinalização Wnt/genética , Grupo com Ancestrais do Continente Africano , Proteína Axina/genética , Feminino , Fator 4 de Crescimento de Fibroblastos/genética , Receptores Frizzled/genética , Regulação da Expressão Gênica , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Doenças Pulmonares Intersticiais/genética , Doenças Pulmonares Intersticiais/metabolismo , Masculino , Metaloproteinase 7 da Matriz/genética , Miosite/genética , Miosite/metabolismo , Proteínas de Neoplasias , Fenótipo , Análise de Componente Principal , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição SOXF/genética , Esclerodermia Difusa/metabolismo , África do Sul , Fator 1 de Transcrição de Linfócitos T/genética , Transcriptoma , Proteínas Wnt/genética
13.
Hum Cell ; 32(1): 31-40, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30225781

RESUMO

The prognosis of colorectal cancer (CRC) is still very poor, owing to the high incidence of metastasis. Long noncoding RNA TCF7 (lncTCF7) has been shown to play critical roles in human CRC development and progression, but the molecular mechanisms of lncTCF7 in CRC are still unknown. This study aimed to explore the functions and molecular mechanisms of lncTCF7 on the migration and invasion of CRC cells. Notably, lncTCF7 was highly expressed in CRC cell lines relative to normal colonic epithelial cells. LncTCF7 knockdown significantly inhibited migration and invasion of CRC cells. In addition, TCF7 was highly expressed in CRC cell lines relative to that in normal colonic epithelial cells and its expression was significantly decreased in CRC cells transfected with si-lncTCF7. RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays showed that LncTCF7 recruits BAF170 to activate the TCF7 promoter and regulate TCF7 expression. TCF7 overexpression could promote migration and invasion in CRC cells transfected with si-lncTCF7, which reversed the effect of lncTCF7 on the migration and invasion of CRC cells. In conclusion, our data indicate that the downregulation of lncTCF7 significantly inhibits migration and invasion of CRC cells by inhibiting TCF7 expression, suggesting that lncTCF7 may be a potential target for CRC therapy.


Assuntos
Movimento Celular/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Regulação para Baixo/genética , Regulação para Baixo/fisiologia , Expressão Gênica/genética , RNA Longo não Codificante/fisiologia , Fator 1 de Transcrição de Linfócitos T/genética , Fator 1 de Transcrição de Linfócitos T/metabolismo , Linhagem Celular Tumoral , Neoplasias Colorretais/terapia , Proteínas de Ligação a DNA , Progressão da Doença , Técnicas de Silenciamento de Genes , Humanos , Terapia de Alvo Molecular , Invasividade Neoplásica/genética , RNA Longo não Codificante/metabolismo , Fatores de Transcrição/metabolismo
14.
Biofactors ; 45(1): 24-34, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30521071

RESUMO

The effects of radiation are known to be potentiated by N-3 polyunsaturated fatty acids, which modulate several signaling pathways, but the molecular mechanisms through which these fatty acids enhance the anticancer effects of irradiation in colorectal cancer (CRC) treatment remain poorly elucidated. Here, we aimed to ascertain whether the fatty acid docosahexaenoic acid (DHA) exerts a modulating effect on the response elicited by radiation treatment (RT). Two CRC cell lines, Caco-2 and HT-29, were exposed to RT, DHA, or both (DHA + RT) for various times, and then cell viability, proliferation, and clonogenicity were assessed. Moreover, cell cycle, apoptosis, and necrosis were analyzed using flow cytometry, and the involvement of WNT/ß-catenin signaling was investigated by immunofluorescence to determine nuclear ß-catenin, GSK3ß phosphorylation status, and TCF/LEF-activity reporter. DHA and RT applied separately diminished the viability of both HT-29 and Caco-2 cells, and DHA + RT caused a further reduction in proliferation mainly in HT-29 cells, particularly in terms of colony formation. Concomitantly, our results verified cell cycle arrest in G0/G1 phase, a reduction of cyclin D1 expression, and a decrease in GSK3ß phosphorylation after the combined treatment. Furthermore, immunofluorescence quantification revealed that nuclear ß-catenin was increased in RT-exposed cells, but this effect was abrogated in cells exposed to DHA + RT, and the results of TCF/LEF-activity assays confirmed that DHA attenuated the increase in nuclear ß-catenin activity induced by irradiation. Our finding shows that DHA applied in combination with RT enhanced the antitumor effects of irradiation on CRC cells, and that the underlying mechanism involved the WNT/ß-catenin pathway. © 2018 BioFactors, 45(1):24-34, 2019.


Assuntos
Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Ácidos Docosa-Hexaenoicos/farmacologia , Raios gama , Regulação Neoplásica da Expressão Gênica , Glicogênio Sintase Quinase 3 beta/genética , beta Catenina/genética , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Células CACO-2 , Pontos de Checagem do Ciclo Celular/genética , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Ensaio de Unidades Formadoras de Colônias , Ciclina D1/genética , Ciclina D1/metabolismo , Relação Dose-Resposta a Droga , Glicogênio Sintase Quinase 3 beta/metabolismo , Células HT29 , Humanos , Fator 1 de Ligação ao Facilitador Linfoide/genética , Fator 1 de Ligação ao Facilitador Linfoide/metabolismo , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Fator 1 de Transcrição de Linfócitos T/genética , Fator 1 de Transcrição de Linfócitos T/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo
15.
Croat Med J ; 59(5): 213-223, 2018 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-30394013

RESUMO

AIM: To identify the involvement of Secreted Frizzled Related Protein 1 (SFRP1) promoter hypermethylation in different malignancy grades of astrocytoma and assess its association with beta-catenin, lymphoid-enhancer factor 1, and T-cell factor 1. METHODS: Twenty-six astrocytoma samples were collected from 2008-2015. Promoter hypermethylation was evaluated by methylation-specific polymerase-chain-reaction and protein expression by immunohistochemistry and stereological analysis. The staining intensity was scored by comparing immunoreactivity with normal tissue and by using 10% and 50% cut-offs. RESULTS: SFRP1 promoter methylation was found in 32% of astrocytomas. The number of hypermethylated samples increased in higher astrocytoma grades and was the highest in glioblastoma (P=0.042 compared to other astrocytoma grades). There was 45.8% of samples with the lack of or weak expression of SFRP1 protein and 29.2% with strong expression. Samples with methylated promoter expressed significantly less SFRP1 than samples with unmethylated promoter (P=0.031). Beta-catenin expression levels were elevated. Yet, glioblastomas with unmethylated SFRP1 promoter had significantly less beta-catenin (P=0.033). Strong expression of lymphoid-enhancer factor 1 was associated to higher astrocytoma grades (P=0.006). CONCLUSION: SFRP1 gene was epigenetically silenced in glioblastomas when compared to low astrocytoma grades, which may suggest that the lack of its protein is involved in astrocytoma progression.


Assuntos
Astrocitoma/genética , Neoplasias Encefálicas/genética , Metilação de DNA , Peptídeos e Proteínas de Sinalização Intercelular/genética , Proteínas de Membrana/genética , Regiões Promotoras Genéticas , Adulto , Idoso , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Análise Mutacional de DNA , DNA de Neoplasias/genética , Epigenômica , Éxons , Feminino , Inativação Gênica , Humanos , Imuno-Histoquímica , Fator 1 de Ligação ao Facilitador Linfoide/genética , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Fator 1 de Transcrição de Linfócitos T/genética , Adulto Jovem , beta Catenina/genética
16.
Immunity ; 49(4): 678-694.e5, 2018 10 16.
Artigo em Inglês | MEDLINE | ID: mdl-30314757

RESUMO

CD8+ T cell exhaustion impedes control of chronic viral infection; yet how new T cell responses are mounted during chronic infection is unclear. Unlike T cells primed at the onset of infection that rapidly differentiate into effectors and exhaust, we demonstrate that virus-specific CD8+ T cells primed after establishment of chronic LCMV infection preferentially generate memory-like transcription factor TCF1+ cells that were transcriptionally and proteomically distinct, less exhausted, and more responsive to immunotherapy. Mechanistically, adaptations of antigen-presenting cells and diminished T cell signaling intensity promoted differentiation of the memory-like subset at the expense of rapid effector cell differentiation, which was now highly dependent on IL-21-mediated CD4+ T cell help for its functional generation. Chronic viral infection similarly redirected de novo differentiation of tumor-specific CD8+ T cells, ultimately preventing cancer control. Thus, targeting these T cell stimulatory pathways could enable strategies to control chronic infection, tumors, and enhance immunotherapeutic efficacy.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Diferenciação Celular/imunologia , Imunidade/imunologia , Memória Imunológica/imunologia , Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Animais , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Células Apresentadoras de Antígenos/virologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/virologia , Diferenciação Celular/genética , Doença Crônica , Perfilação da Expressão Gênica/métodos , Imunidade/genética , Memória Imunológica/genética , Imunoterapia , Coriomeningite Linfocítica/terapia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/fisiologia , Camundongos Endogâmicos C57BL , Proteômica/métodos , Fator 1 de Transcrição de Linfócitos T/genética , Fator 1 de Transcrição de Linfócitos T/imunologia , Fator 1 de Transcrição de Linfócitos T/metabolismo
17.
Gene ; 679: 119-125, 2018 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-30179681

RESUMO

Numerous long noncoding RNAs (lncRNAs) are reported to be dysregulated in glioma. However, how lncRNA participates in the process of glioma development and progression still remains elusive. Here, we identified a novel lncRNA LOC728196 highly expressed in glioma tissues. LOC728196 high expression predicts low survival rate in patients. Our data proved that LOC728196 knockdown repressed cellular growth, migration and invasion in vitro. Silencing LOC728196 led to impaired growth of glioma in vivo. Mechanistic studies further demonstrated that LOC728196 acts as the sponge for miR-513c to upregulate TCF7 expression. We observed a reciprocal inhibition between LOC728196 and miR-513c. Rescue assay showed that either inhibition of miR-513c or TCF7 overexpression restored the abilities of proliferation, migration and invasion in LOC728196-silenced glioma cells. Taken together, our study provides a comprehensive investigation on the role of LOC728196 in glioma progression and contributes to understanding the vital role of competing endogenous RNA (ceRNA).


Assuntos
Neoplasias Encefálicas/patologia , Glioma/patologia , MicroRNAs/genética , RNA Longo não Codificante/genética , Fator 1 de Transcrição de Linfócitos T/genética , Regiões 3' não Traduzidas , Animais , Neoplasias Encefálicas/genética , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Glioma/genética , Humanos , Masculino , Camundongos , Transplante de Neoplasias , Prognóstico , Análise de Sobrevida , Regulação para Cima
18.
Biosystems ; 172: 26-36, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30110600

RESUMO

The Adenomatous Polyposis Coli (APC) gene is a multifunctional gene that plays a major role in regulating the Wnt signalling pathway. The Wnt pathway, when activated by Wnt signalling molecules, initiates cell division. Mutation of APC disrupts the regulation and causes continuous activation of the Wnt pathway even in the absence of Wnt signals, thus causing uncontrolled cell proliferation. APC regulates the Wnt pathway by controlling the formation of the nuclear complex ß-catenin/TCF that initiates the transcription of the Wnt target genes. There are at least five mechanisms by which APC can regulate the formation of the ß-catenin/TCF complex: This paper presents a computational model for the Wnt pathway that explicitly includes the above five roles of APC in regulating ß-catenin/TCF formation. We use this computational model to perform in-silico experiments to study the effect of different functional losses of APC on the level of ß-catenin/TCF complex. The simulations also demonstrate the different outcomes that could be expected when the system is governed by different hypotheses.


Assuntos
Proteína da Polipose Adenomatosa do Colo/metabolismo , Simulação por Computador , Modelos Biológicos , Neoplasias/metabolismo , Fator 1 de Transcrição de Linfócitos T/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Proteína da Polipose Adenomatosa do Colo/genética , Humanos , Neoplasias/patologia , Fator 1 de Transcrição de Linfócitos T/genética , beta Catenina/genética
19.
Sci Rep ; 8(1): 11185, 2018 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-30046100

RESUMO

Clinical studies have suggested association of some hepatitis C virus (HCV) subtypes or isolates with progression toward hepatocellular carcinoma (HCC). HCV core protein has been reported to interfere with host Wnt/ß-catenin pathway, a cell fate-determining pathway, which plays a major role in HCC. Here, we investigated the impact of HCV core genetic variability in the dysregulation of Wnt/ß-catenin pathway. We used both transient expression of core proteins from clinical isolates of HCV subtypes 1a (Cambodia), 4a (Romania) and 4f (Cameroon) and infection systems based on a set of engineered intergenotypic recombinant viruses encoding core from these various clinical strains. We found that TCF transcription factor-dependent reporter activity was upregulated by core in a strain-specific manner. We documented core sequence-specific transcriptional upregulation of several ß-catenin downstream target genes associated with cell proliferation and malignant transformation, fibrogenesis or fat accumulation. The extent of ß-catenin nuclear translocation varied in accordance with ß-catenin downstream gene upregulation in infected cells. Pairwise comparisons of subgenotypic core recombinants and mutated core variants unveiled the critical role of core residues 64 and 71 in these dysregulations. In conclusion, this work identified natural core polymorphisms involved in HCV strain-specific activation of Wnt/ß-catenin pathway in relevant infection systems.


Assuntos
Carcinoma Hepatocelular/genética , Hepacivirus/genética , Neoplasias Hepáticas/genética , beta Catenina/genética , Transporte Ativo do Núcleo Celular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Proliferação de Células/genética , Transformação Celular Neoplásica/genética , Regulação Neoplásica da Expressão Gênica , Genótipo , Células HEK293 , Hepacivirus/patogenicidade , Hepatite C/genética , Hepatite C/patologia , Hepatite C/virologia , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Fator 1 de Transcrição de Linfócitos T/genética , Via de Sinalização Wnt/genética
20.
Rinsho Ketsueki ; 59(4): 439-447, 2018.
Artigo em Japonês | MEDLINE | ID: mdl-29743405

RESUMO

The outcome of treatment-refractory and/or relapsed pediatric T-cell acute lymphoblastic leukemia (T-ALL) is extremely poor, and the genetic basis of these cases remains poorly understood. Here, we report comprehensive profiling of 121 cases of pediatric T-ALL using RNA sequencing and/or targeted capture sequencing through which we identified new recurrent gene fusions involving SPI1 (STMN1-SPI1 and TCF7-SPI1). Cases positive for fusions involving SPI1 (encoding PU.1), which accounted for 3.9% (7/181) of the total examined pediatric T-ALL cases, had uniformly poor overall survival. These cases represent a subset of pediatric T-ALL distinguishable from the known T-ALL subsets in terms of expression of genes involved in T cell pre-commitment, establishment of T cell identity, and post-ß-selection maturation with respect to mutational profile. PU.1 fusion proteins retained transcriptional activity and induced cell proliferation on constitutive expression in mouse stem/progenitor cells, resulting in a maturation block. Our findings highlight the unique role of SPI1 fusions in high-risk pediatric T-ALL.


Assuntos
Fusão Gênica , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Proteínas Proto-Oncogênicas/genética , Transativadores/genética , Animais , Criança , Humanos , Camundongos , Mutação , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Prognóstico , Estatmina/genética , Fator 1 de Transcrição de Linfócitos T/genética
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