RESUMEN
Small-cell neuroendocrine carcinoma (SCNEC) of the cervix is a rare disease characterized by a high incidence of mixed tumors with other types of cancer. The mechanism underlying this mixed phenotype is not well understood. This study established a panel of organoid lines from patients with SCNEC of the cervix and ultimately focused on one line, which retained a mixed tumor phenotype, both in vitro and in vivo. Histologically, both organoids and xenograft tumors showed distinct differentiation into either SCNEC or adenocarcinoma in some regions and ambiguous differentiation in others. Tracking single cells indicated the existence of cells with bipotential differentiation toward SCNEC and adenocarcinomas. Single-cell transcriptional analysis identified three distinct clusters: SCNEC-like, adenocarcinoma-like, and a cluster lacking specific differentiation markers. The expression of neuroendocrine markers was enriched in the SCNEC-like cluster but not exclusively. Human papillomavirus 18 E6 was enriched in the SCNEC-like cluster, which showed higher proliferation and lower levels of the p53 pathway. After treatment with anticancer drugs, the expression of adenocarcinoma markers increased, whereas that of SCNEC decreased. Using a reporter system for keratin 19 expression, changes in the differentiation of each cell were shown to be associated with the shift in differentiation induced by drug treatment. These data suggest that mixed SCNEC/cervical tumors have a clonal origin and are characterized by an ambiguous and flexible differentiation state.
Asunto(s)
Carcinoma Neuroendocrino , Carcinoma de Células Pequeñas , Neoplasias del Cuello Uterino , Femenino , Humanos , Cuello del Útero/metabolismo , Cuello del Útero/patología , Neoplasias del Cuello Uterino/patología , Carcinoma Neuroendocrino/metabolismo , Carcinoma de Células Pequeñas/genética , Carcinoma de Células Pequeñas/patología , Carcinoma de Células Pequeñas/terapiaRESUMEN
Mammalian genomes encode large number of long noncoding RNAs (lncRNAs) that play key roles in various biological processes, including proliferation, differentiation, and stem cell pluripotency. Recent studies have addressed that some lncRNAs are dysregulated in human cancers and may play crucial roles in tumor development and progression. Here, we show that the lncRNA ZNNT1 is required for the proliferation and tumorigenicity of colon cancer cells with wild-type p53. ZNNT1 knockdown leads to decreased ubiquitination and stabilization of p53 protein. Moreover, we demonstrate that ZNNT1 needs to interact with SART3 to destabilize p53 and to promote the proliferation and tumorigenicity of colon cancer cells. We further show that SART3 is associated with the ubiquitin-specific peptidase USP15 and that ZNNT1 may induce p53 destabilization by inhibiting this interaction. These results suggest that ZNNT1 interferes with the SART3-USP15 complex-mediated stabilization of p53 protein and thereby plays important roles in the proliferation and tumorigenicity of colon cancer cells. Our findings suggest that ZNNT1 may be a promising molecular target for the therapy of colon cancer.
RESUMEN
Dominant-negative mutations associated with signal transducer and activator of transcription 3 (STAT3) signaling, which controls epithelial proliferation in various tissues, lead to atopic dermatitis in hyper IgE syndrome. This dermatitis is thought to be attributed to defects in STAT3 signaling in type 17 helper T cellãspecification. However, the role of STAT3 signaling in skin epithelial cells remains unclear. We found that STAT3 signaling in keratinocytes is required to maintain skin homeostasis by negatively controlling the expression of hair follicle-specific keratin genes. These expression patterns correlated with the onset of dermatitis, which was observed in specific pathogen-free conditions but not in germ-free conditions, suggesting the involvement of Toll-like receptor-mediated inflammatory responses. Thus, our study suggests that STAT3-dependent gene expression in keratinocytes plays a critical role in maintaining the homeostasis of skin, which is constantly exposed to microorganisms.
Asunto(s)
Folículo Piloso/fisiología , Factor de Transcripción STAT3/fisiología , Animales , Dermatitis Atópica/etiología , Dermatitis Atópica/genética , Dermatitis Atópica/inmunología , Modelos Animales de Enfermedad , Femenino , Regulación de la Expresión Génica , Folículo Piloso/inmunología , Homeostasis , Humanos , Queratinocitos/inmunología , Queratinocitos/fisiología , Queratinas/genética , Masculino , Ratones , Ratones de la Cepa 129 , Ratones Endogámicos C57BL , Ratones Noqueados , Factor de Transcripción STAT3/deficiencia , Factor de Transcripción STAT3/genética , Factor de Transcripción STAT3/inmunología , Transducción de Señal , Piel/inmunología , Piel/microbiología , Fenómenos Fisiológicos de la Piel , Células Th17/inmunologíaRESUMEN
NF-κB is a transcription factor that activates super enhancers (SEs) and typical enhancers (TEs) and triggers threshold and graded gene expression, respectively. However, the mechanisms by which NF-κB selectively participates in these enhancers remain unclear. Here we show using mouse primary B lymphocytes that SE activity simultaneously associates with chromatin opening and enriched NF-κB binding, resulting in a higher fold change and threshold expression upon B cell receptor (BCR) activation. The higher fold change results from longer DNA, whereas the threshold response is explained by synergy in DNA-NF-κB binding and is supported by the coexistence of PU.1 and NF-κB in a SE before cell stimulation. This model indicates that the pre-existing NF-κB functions as a seed and triggers its processive binding upon BCR activation. Our mathematical modeling of the single-cell transcriptome reveals an additional role for SEs in divergent clonal responses in B cells.
Asunto(s)
Elementos de Facilitación Genéticos/genética , FN-kappa B/metabolismo , Animales , Linfocitos B/citología , Linfocitos B/metabolismo , Células Cultivadas , Cromatina/metabolismo , Regulación de la Expresión Génica , Histonas/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Modelos Biológicos , Unión Proteica , Proteínas Proto-Oncogénicas/metabolismo , Transactivadores/metabolismo , Factor de Transcripción ReIA/metabolismoRESUMEN
Regnase-1-mediated mRNA decay (RMD), in which inflammatory mRNAs harboring specific stem-loop structures are degraded, is a critical part of proper immune homeostasis. Prior to initial translation, Regnase-1 associates with target stem-loops but does not carry out endoribonucleolytic cleavage. Single molecule imaging revealed that UPF1 is required to first unwind the stem-loops, thus licensing Regnase-1 to proceed with RNA degradation. Following translation, Regnase-1 physically associates with UPF1 using two distinct points of interaction: The Regnase-1 RNase domain binds to SMG1-phosphorylated residue T28 in UPF1; in addition, an intrinsically disordered segment in Regnase-1 binds to the UPF1 RecA domain, enhancing the helicase activity of UPF1. The SMG1-UPF1-Regnase-1 axis targets pioneer rounds of translation and is critical for rapid resolution of inflammation through restriction of the number of proteins translated by a given mRNA. Furthermore, small-molecule inhibition of SMG1 prevents RNA unwinding in dendritic cells, allowing post-transcriptional control of innate immune responses.
Asunto(s)
Macrófagos Peritoneales/inmunología , Degradación de ARNm Mediada por Codón sin Sentido/inmunología , Proteínas Serina-Treonina Quinasas/genética , ARN Mensajero/genética , Ribonucleasas/genética , Transactivadores/genética , Animales , Fibroblastos/citología , Fibroblastos/inmunología , Células HEK293 , Células HeLa , Homeostasis/genética , Homeostasis/inmunología , Humanos , Inmunidad Innata , Inflamación , Secuencias Invertidas Repetidas , Macrófagos/citología , Macrófagos/inmunología , Macrófagos Peritoneales/citología , Ratones , Ratones Noqueados , Mutación , Cultivo Primario de Células , Unión Proteica , Biosíntesis de Proteínas , Dominios y Motivos de Interacción de Proteínas , Proteínas Serina-Treonina Quinasas/inmunología , ARN Mensajero/metabolismo , Ribonucleasas/deficiencia , Ribonucleasas/inmunología , Imagen Individual de Molécula , Transactivadores/inmunologíaRESUMEN
Whole-body metabolic homeostasis is tightly controlled by hormone-like factors with systemic or paracrine effects that are derived from nonendocrine organs, including adipose tissue (adipokines) and liver (hepatokines). Fibroblast growth factor 21 (FGF21) is a hormone-like protein, which is emerging as a major regulator of whole-body metabolism and has therapeutic potential for treating metabolic syndrome. However, the mechanisms that control FGF21 levels are not fully understood. Herein, we demonstrate that FGF21 production in the liver is regulated via a posttranscriptional network consisting of the CCR4-NOT deadenylase complex and RNA-binding protein tristetraprolin (TTP). In response to nutrient uptake, CCR4-NOT cooperates with TTP to degrade AU-rich mRNAs that encode pivotal metabolic regulators, including FGF21. Disruption of CCR4-NOT activity in the liver, by deletion of the catalytic subunit CNOT6L, increases serum FGF21 levels, which ameliorates diet-induced metabolic disorders and enhances energy expenditure without disrupting bone homeostasis. Taken together, our study describes a hepatic CCR4-NOT/FGF21 axis as a hitherto unrecognized systemic regulator of metabolism and suggests that hepatic CCR4-NOT may serve as a target for devising therapeutic strategies in metabolic syndrome and related morbidities.
Asunto(s)
Exorribonucleasas , Factores de Crecimiento de Fibroblastos , Hepatocitos , Homeostasis , Ribonucleasas , Animales , Células Cultivadas , Dieta Alta en Grasa , Exorribonucleasas/genética , Exorribonucleasas/metabolismo , Factores de Crecimiento de Fibroblastos/genética , Factores de Crecimiento de Fibroblastos/metabolismo , Hepatocitos/metabolismo , Hepatocitos/fisiología , Homeostasis/genética , Homeostasis/fisiología , Humanos , Hígado/química , Hígado/metabolismo , Hígado/patología , Síndrome Metabólico/metabolismo , Ratones , Ratones Transgénicos , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ribonucleasas/genética , Ribonucleasas/metabolismoRESUMEN
The tumor microenvironment is fundamental to cancer progression, and the influence of its mechanical properties is increasingly being appreciated. Tamoxifen has been used for many years to treat estrogen-positive breast cancer. Here we report that tamoxifen regulates the level and activity of collagen cross-linking and degradative enzymes, and hence the organization of the extracellular matrix, via a mechanism involving both the G protein-coupled estrogen receptor (GPER) and hypoxia-inducible factor-1 alpha (HIF-1A). We show that tamoxifen reduces HIF-1A levels by suppressing myosin-dependent contractility and matrix stiffness mechanosensing. Tamoxifen also downregulates hypoxia-regulated genes and increases vascularization in PDAC tissues. Our findings implicate the GPER/HIF-1A axis as a master regulator of peri-tumoral stromal remodeling and the fibrovascular tumor microenvironment and offer a paradigm shift for tamoxifen from a well-established drug in breast cancer hormonal therapy to an alternative candidate for stromal targeting strategies in PDAC and possibly other cancers.
Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Carcinoma Ductal Pancreático/tratamiento farmacológico , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Receptores de Estrógenos/genética , Receptores Acoplados a Proteínas G/genética , Tamoxifeno/administración & dosificación , Adenocarcinoma/genética , Adenocarcinoma/patología , Animales , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patología , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Reprogramación Celular/efectos de los fármacos , Fibroblastos/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Ratones , Miosinas/genética , Neovascularización Patológica/tratamiento farmacológico , Neovascularización Patológica/genética , Neovascularización Patológica/patología , Transducción de Señal/efectos de los fármacos , Microambiente Tumoral/efectos de los fármacosRESUMEN
Acquired drug resistance is the major reason why patients fail to respond to cancer therapies. It is a challenging task to determine the tipping point of endocrine resistance and detect the associated molecules. Derived from new systems biology theory, the dynamic network biomarker (DNB) method is designed to quantitatively identify the tipping point of a drastic system transition and can theoretically identify DNB genes that play key roles in acquiring drug resistance. We analyzed time-course mRNA sequence data generated from the tamoxifen-treated estrogen receptor (ER)-positive MCF-7 cell line, and identified the tipping point of endocrine resistance with its leading molecules. The results show that there is interplay between gene mutations and DNB genes, in which the accumulated mutations eventually affect the DNB genes that subsequently cause the change of transcriptional landscape, enabling full-blown drug resistance. Survival analyses based on clinical datasets validated that the DNB genes were associated with the poor survival of breast cancer patients. The results provided the detection for the pre-resistance state or early signs of endocrine resistance. Our predictive method may greatly benefit the scheduling of treatments for complex diseases in which patients are exposed to considerably different drugs and may become drug resistant.
Asunto(s)
Biomarcadores de Tumor/metabolismo , Neoplasias de la Mama/metabolismo , Antineoplásicos Hormonales/química , Antineoplásicos Hormonales/farmacología , Apoptosis/efectos de los fármacos , Apoptosis/genética , Resistencia a Antineoplásicos/genética , Femenino , Humanos , Células MCF-7 , Mutación/genética , Biología de Sistemas , Tamoxifeno/química , Tamoxifeno/farmacologíaRESUMEN
Paired-end RNA sequencing (RNA-seq) is usually applied to the quantification of long transcripts such as messenger or long non-coding RNAs, in which case overlapping pairs are discarded. In contrast, RNA-seq on short RNAs (≤ 200 nt) is typically carried out in single-end mode, as the additional cost associated with paired-end would only translate into redundant sequence information. Here, we exploit paired-end sequencing of short RNAs as a strategy to filter out sequencing errors and apply this method to the identification of adenosine-to-inosine (A-to-I) RNA editing events on human precursor microRNA (pre-miRNA) and mature miRNA. Combined with RNA immunoprecipitation sequencing (RIP-seq) of A-to-I RNA editing enzymes, this method takes full advantage of deep sequencing technology to identify RNA editing sites with unprecedented resolution in terms of editing efficiency.
Asunto(s)
Inmunoprecipitación/métodos , MicroARNs/genética , Edición de ARN , Análisis de Secuencia de ARN/métodos , Células HeLa , Humanos , MicroARNs/metabolismoRESUMEN
Adenosine deaminases acting on RNA (ADARs) catalyze the deamination of adenosine (A) to inosine (I). A-to-I RNA editing targets double-stranded RNA (dsRNA), and increases the complexity of gene regulation by modulating base pairing-dependent processes such as splicing, translation, and microRNA (miRNA)-mediated gene silencing. This study investigates the genome-wide binding preferences of the nuclear constitutive isoforms ADAR1-p110 and ADAR2 on human miRNA species by RNA immunoprecipitation of ADAR-bound small RNAs (RIP-seq). Our results suggest that secondary structure predicted by base-pairing probability in the mainly double-stranded region of a pre-miRNA or mature miRNA duplex may determine ADAR isoform preference for binding distinct subpopulations of miRNAs. Furthermore, we identify 31 unique editing sites with statistical significance, 19 sites of which are novel editing sites. Editing sites are enriched in the seed region responsible for target recognition by miRNAs, and isoform-specific nucleotide motifs in the immediate vicinity and opposite of editing sites are consistent with previous studies, and further reveal that ADAR2 may edit A/C bulges more frequently than ADAR1-p110 in the context of miRNA.
Asunto(s)
Adenosina Desaminasa/metabolismo , Emparejamiento Base , MicroARNs/metabolismo , Edición de ARN , Proteínas de Unión al ARN/metabolismo , Adenosina/genética , Adenosina Desaminasa/química , Adenosina Desaminasa/genética , Desaminación , Estudio de Asociación del Genoma Completo , Células HeLa , Humanos , Inosina/genética , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , MicroARNs/química , MicroARNs/genética , Motivos de Nucleótidos , Estructura Secundaria de Proteína , Proteínas de Unión al ARN/química , Proteínas de Unión al ARN/genéticaRESUMEN
Feedback control is a key mechanism in signal transduction, intimately involved in regulating the outcome of the cellular response. Here, we report a novel mechanism by which PHLDA1, Pleckstrin homology-like domain, family A, member 1, negatively regulates ErbB receptor signaling by inhibition of receptor oligomerization. We have found that the ErbB3 ligand, heregulin, induces PHILDA1 expression in MCF-7 cells. Transcriptionally-induced PHLDA1 protein directly binds to ErbB3, whereas knockdown of PHLDA1 increases complex formation between ErbB3 and ErbB2. To provide insight into the mechanism for our time-course and single-cell experimental observations, we performed a systematic computational search of network topologies of the mathematical models based on receptor dimer-tetramer formation in the ErbB activation processes. Our results indicate that only a model in which PHLDA1 inhibits formation of both dimers and tetramer can explain the experimental data. Predictions made from this model were further validated by single-molecule imaging experiments. Our studies suggest a unique regulatory feature of PHLDA1 to inhibit the ErbB receptor oligomerization process and thereby control the activity of receptor signaling network.
Asunto(s)
Receptor ErbB-3/metabolismo , Factores de Transcripción/metabolismo , Humanos , Células MCF-7 , Modelos Químicos , Neurregulina-1/metabolismo , Multimerización de Proteína , Transducción de Señal , Imagen Individual de Molécula , Análisis de la Célula Individual , Factores de Transcripción/fisiología , Transcripción GenéticaRESUMEN
MOTIVATION: Drug combination therapy for treatment of cancers and other multifactorial diseases has the potential of increasing the therapeutic effect, while reducing the likelihood of drug resistance. In order to reduce time and cost spent in comprehensive screens, methods are needed which can model additive effects of possible drug combinations. RESULTS: We here show that the transcriptional response to combinatorial drug treatment at promoters, as measured by single molecule CAGE technology, is accurately described by a linear combination of the responses of the individual drugs at a genome wide scale. We also find that the same linear relationship holds for transcription at enhancer elements. We conclude that the described approach is promising for eliciting the transcriptional response to multidrug treatment at promoters and enhancers in an unbiased genome wide way, which may minimize the need for exhaustive combinatorial screens. AVAILABILITY AND IMPLEMENTATION: The CAGE sequence data used in this study is available in the DDBJ Sequence Read Archive (http://trace.ddbj.nig.ac.jp/index_e.html), accession number DRP001113. CONTACT: xin.gao@kaust.edu.sa or erik.arner@riken.jp. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Elementos de Facilitación Genéticos/efectos de los fármacos , Regiones Promotoras Genéticas/efectos de los fármacos , Genoma Humano , Humanos , Análisis de Regresión , Transcripción Genética/efectos de los fármacosRESUMEN
MicroRNAs (miRNAs) are short non-coding RNAs with key roles in cellular regulation. As part of the fifth edition of the Functional Annotation of Mammalian Genome (FANTOM5) project, we created an integrated expression atlas of miRNAs and their promoters by deep-sequencing 492 short RNA (sRNA) libraries, with matching Cap Analysis Gene Expression (CAGE) data, from 396 human and 47 mouse RNA samples. Promoters were identified for 1,357 human and 804 mouse miRNAs and showed strong sequence conservation between species. We also found that primary and mature miRNA expression levels were correlated, allowing us to use the primary miRNA measurements as a proxy for mature miRNA levels in a total of 1,829 human and 1,029 mouse CAGE libraries. We thus provide a broad atlas of miRNA expression and promoters in primary mammalian cells, establishing a foundation for detailed analysis of miRNA expression patterns and transcriptional control regions.
Asunto(s)
Perfilación de la Expresión Génica/métodos , MicroARNs/genética , Anotación de Secuencia Molecular , Regiones Promotoras Genéticas/genética , Animales , Células Cultivadas , Biblioteca de Genes , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Ratones , MicroARNs/metabolismoRESUMEN
The ErbB receptor signaling pathway plays an important role in the regulation of cellular proliferation, survival and differentiation, and dysregulation of the pathway is linked to various types of human cancer. Mathematical models have been developed as a practical complementary approach to deciphering the complexity of ErbB receptor signaling and elucidating how the pathways discriminate between ligands to induce different cell fates. In this study, we developed a simulator to accurately calculate the dynamic sensitivity of extracellular-signal-regulated kinase (ERK) activity (ERK*) and Akt activity (Akt*), downstream of the ErbB receptors stimulated with epidermal growth factor (EGF) and heregulin (HRG). To demonstrate the feasibility of this simulator, we estimated how the reactions critically responsible for ERK* and Akt* change with time and in response to different doses of EGF and HRG, and predicted that only a small number of reactions determine ERK* and Akt*. ERK* increased steeply with increasing HRG dose until saturation, while showing a gently rising response to EGF. Akt* had a gradual wide-range response to HRG and a blunt response to EGF. Akt* was sensitive to perturbations of intracellular kinetics, while ERK* was more robust due to multiple, negative feedback loops. Overall, the simulator predicted reactions that were critically responsible for ERK* and Akt* in response to the dose of EGF and HRG, illustrated the response characteristics of ERK* and Akt*, and estimated mechanisms for generating robustness in the ErbB signaling network.
Asunto(s)
Receptores ErbB/metabolismo , Modelos Biológicos , Simulación por Computador , Factor de Crecimiento Epidérmico/metabolismo , Receptores ErbB/antagonistas & inhibidores , Humanos , Cinética , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Células MCF-7 , Proteínas/metabolismo , Proteínas Proto-Oncogénicas c-akt/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacosRESUMEN
BACKGROUND: The skin barrier acts as the first line of defense against constant exposure to biological, microbial, physical, and chemical environmental stressors. Dynamic interplay between defects in the skin barrier, dysfunctional immune responses, and environmental stressors are major factors in the development of atopic dermatitis (AD). A systems biology modeling approach can yield significant insights into these complex and dynamic processes through integration of prior biological data. OBJECTIVE: We sought to develop a multiscale mathematical model of AD pathogenesis that describes the dynamic interplay between the skin barrier, environmental stress, and immune dysregulation and use it to achieve a coherent mechanistic understanding of the onset, progression, and prevention of AD. METHODS: We mathematically investigated synergistic effects of known genetic and environmental risk factors on the dynamic onset and progression of the AD phenotype, from a mostly asymptomatic mild phenotype to a severe treatment-resistant form. RESULTS: Our model analysis identified a "double switch," with 2 concatenated bistable switches, as a key network motif that dictates AD pathogenesis: the first switch is responsible for the reversible onset of inflammation, and the second switch is triggered by long-lasting or frequent activation of the first switch, causing irreversible onset of systemic TH2 sensitization and worsening of AD symptoms. CONCLUSIONS: Our mathematical analysis of the bistable switch predicts that genetic risk factors decrease the threshold of environmental stressors to trigger systemic TH2 sensitization. This analysis predicts and explains 4 common clinical AD phenotypes from a mild and reversible phenotype through to severe and recalcitrant disease and provides a mechanistic explanation for clinically demonstrated preventive effects of emollient treatments against development of AD.
Asunto(s)
Dermatitis Atópica/etiología , Modelos Biológicos , Alérgenos/inmunología , Animales , Dermatitis Atópica/genética , Dermatitis Atópica/inmunología , Dermatitis Atópica/prevención & control , Emolientes/uso terapéutico , Humanos , Inmunoglobulina E/sangre , Inmunoglobulina E/inmunología , Lipopolisacáridos , Ratones Noqueados , Ovalbúmina/inmunología , Fenotipo , Factores de Riesgo , Factor de Transcripción STAT3/genética , Piel/efectos de los fármacos , Piel/inmunología , Piel/patologíaRESUMEN
Virus infection induces the development of T follicular helper (TFH) and T helper 1 (TH1) cells. Although TFH cells are important in anti-viral humoral immunity, the contribution of TH1 cells to a protective antibody response remains unknown. We found that IgG2 antibodies predominated in the response to vaccination with inactivated influenza A virus (IAV) and were responsible for protective immunity to lethal challenge with pathogenic H5N1 and pandemic H1N1 IAV strains, even in mice that lacked TFH cells and germinal centers. The cytokines interleukin-21 and interferon-γ, which are secreted from TH1 cells, were essential for the observed greater persistence and higher titers of IgG2 protective antibodies. Our results suggest that TH1 induction could be a promising strategy for producing effective neutralizing antibodies against emerging influenza viruses.
Asunto(s)
Centro Germinal/inmunología , Subtipo H1N1 del Virus de la Influenza A/inmunología , Subtipo H5N1 del Virus de la Influenza A/inmunología , Vacunas contra la Influenza/inmunología , Gripe Humana/inmunología , Infecciones por Orthomyxoviridae/inmunología , Células TH1/inmunología , Animales , Anticuerpos Neutralizantes/sangre , Anticuerpos Antivirales/sangre , Células Cultivadas , Humanos , Inmunoglobulina G/sangre , Interferón gamma/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones NoqueadosRESUMEN
Wnt/ß-catenin signaling plays a key role in the tumorigenicity of colon cancer. Furthermore, it has been reported that lncRNAs are dysregulated in several steps of cancer development. Here we show that ß-catenin directly activates the transcription of the long noncoding RNA (lncRNA) ASBEL [antisense ncRNA in the ANA (Abundant in neuroepithelium area)/BTG3 (B-cell translocation gene 3) locus] and transcription factor 3 (TCF3), both of which are required for the survival and tumorigenicity of colorectal cancer cells. ASBEL interacts with and recruits TCF3 to the activating transcription factor 3 (ATF3) locus, where it represses the expression of ATF3. Furthermore, we demonstrate that ASBEL-TCF3-mediated down-regulation of ATF3 expression is required for the proliferation and tumorigenicity of colon tumor cells. ATF3, in turn, represses the expression of ASBEL Our results reveal a pathway involving an lncRNA and two transcription factors that plays a key role in Wnt/ß-catenin-mediated tumorigenesis. These results may provide insights into the variety of biological and pathological processes regulated by Wnt/ß-catenin signaling.
RESUMEN
Aberrant activation of Wnt/ß-catenin signaling is a major driving force in colon cancer. Wnt/ß-catenin signaling induces the expression of the transcription factor c-Myc, leading to cell proliferation and tumorigenesis. c-Myc regulates multiple biological processes through its ability to directly modulate gene expression. Here, we identify a direct target of c-Myc, termed MYU, and show that MYU is upregulated in most colon cancers and required for the tumorigenicity of colon cancer cells. Furthermore, we demonstrate that MYU associates with the RNA binding protein hnRNP-K to stabilize CDK6 expression and thereby promotes the G1-S transition of the cell cycle. These results suggest that the MYU/hnRNP-K/CDK6 pathway functions downstream of Wnt/c-Myc signaling and plays a critical role in the proliferation and tumorigenicity of colon cancer cells.
Asunto(s)
Ciclo Celular , Quinasa 6 Dependiente de la Ciclina/metabolismo , Proteínas Proto-Oncogénicas c-myc/metabolismo , ARN Largo no Codificante/metabolismo , Vía de Señalización Wnt , Animales , Secuencia de Bases , Carcinogénesis/genética , Carcinogénesis/patología , Línea Celular Tumoral , Proliferación Celular , Células Clonales , Neoplasias del Colon/genética , Neoplasias del Colon/patología , Ribonucleoproteína Heterogénea-Nuclear Grupo K/metabolismo , Humanos , Ratones Desnudos , ARN Largo no Codificante/genética , Regulación hacia Arriba/genéticaRESUMEN
Different dynamic behaviours of signalling activity can induce distinct biological responses in a variety of cells. However, the molecular mechanisms that determine the dynamics of kinase activities in immune cells are not well understood. In this study, we showed that the duration of both IκB kinase (IKK) and extracellular signal-regulated kinase (ERK) activities in B cell receptor (BCR)- and CD40-signalling pathways in B cells were regulated by transcriptional feedback loops. We conducted a time-course transcriptome analysis after BCR or CD40 stimulation and identified the following four candidate genes as feedback regulators for IKK and ERK: inhibitor of apoptosis protein (IAP), TNF alpha-induced protein 3, dual-specificity phosphatase 5, and sprouty homolog 2. Quantitative experiments and mathematical modelling suggested that IAP inhibition shortened the duration of IKK and ERK activity following both BCR and CD40 pathway stimulation, indicating a positive role for IAP in B cell signalling. Furthermore, transient kinase activities induced by IAP blockage reduced the levels of delayed expression genes. Together, our findings suggest that IKK and ERK activity durations can be fine-tuned by the coordinated regulation of positive and negative transcriptional feedback and that these network properties determine the biological output of B cells.
Asunto(s)
Linfocitos B/metabolismo , Ligando de CD40/farmacología , Receptores de Antígenos de Linfocitos B/metabolismo , Transducción de Señal , Animales , Línea Celular , Fosfatasas de Especificidad Dual/genética , Quinasas MAP Reguladas por Señal Extracelular/genética , Retroalimentación Fisiológica , Quinasa I-kappa B/genética , Proteínas Inhibidoras de la Apoptosis/genética , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas de la Membrana/genética , Ratones , Proteínas Serina-Treonina Quinasas , Proteínas Proto-Oncogénicas c-bcr/metabolismo , Proteína 3 Inducida por el Factor de Necrosis Tumoral alfa/genéticaRESUMEN
Immunological memory has been believed to be a feature of the adaptive immune system for long period, but recent reports suggest that the innate immune system also exhibits memory-like reaction. Although evidence of innate immune memory is accumulating, no in vivo experimental data has clearly implicated a molecular mechanism, or even a cell-type, for this phenomenon. In this study of data deposited into Gene Expression Omnibus (GEO) under GSE71111, we analyzed the expression profile of peritoneal macrophages isolated from mice pre-administrated with toll-like receptor (TLR) ligands, mimicking pathogen infection. In these macrophages, increased expression of a group of innate immunity-related genes was sustained over a long period of time, and these genes overlapped with ATF7-regulated genes. We conclude that ATF7 plays an important role in innate immune memory in macrophages.