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1.
Nature ; 607(7920): 790-798, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35768505

RESUMO

Ageing is intimately connected to the induction of cell senescence1,2, but why this is so remains poorly understood. A key challenge is the identification of pathways that normally suppress senescence, are lost during ageing and are functionally relevant to oppose ageing3. Here we connected the structural and functional decline of ageing tissues to attenuated function of the master effectors of cellular mechanosignalling YAP and TAZ. YAP/TAZ activity declines during physiological ageing in stromal cells, and mimicking such decline through genetic inactivation of YAP/TAZ in these cells leads to accelerated ageing. Conversely, sustaining YAP function rejuvenates old cells and opposes the emergence of ageing-related traits associated with either physiological ageing or accelerated ageing triggered by a mechano-defective extracellular matrix. Ageing traits induced by inactivation of YAP/TAZ are preceded by induction of tissue senescence. This occurs because YAP/TAZ mechanotransduction suppresses cGAS-STING signalling, to the extent that inhibition of STING prevents tissue senescence and premature ageing-related tissue degeneration after YAP/TAZ inactivation. Mechanistically, YAP/TAZ-mediated control of cGAS-STING signalling relies on the unexpected role of YAP/TAZ in preserving nuclear envelope integrity, at least in part through direct transcriptional regulation of lamin B1 and ACTR2, the latter of which is involved in building the peri-nuclear actin cap. The findings demonstrate that declining YAP/TAZ mechanotransduction drives ageing by unleashing cGAS-STING signalling, a pillar of innate immunity. Thus, sustaining YAP/TAZ mechanosignalling or inhibiting STING may represent promising approaches for limiting senescence-associated inflammation and improving healthy ageing.


Assuntos
Envelhecimento , Proteínas de Membrana , Nucleotidiltransferases , Células Estromais , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , Proteínas de Sinalização YAP , Proteína 2 Relacionada a Actina/metabolismo , Envelhecimento/metabolismo , Senescência Celular , Matriz Extracelular , Envelhecimento Saudável , Imunidade Inata , Lamina Tipo B/metabolismo , Mecanotransdução Celular/genética , Proteínas de Membrana/metabolismo , Membrana Nuclear/metabolismo , Nucleotidiltransferases/metabolismo , Transdução de Sinais , Células Estromais/metabolismo , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/antagonistas & inibidores , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional/metabolismo , Proteínas de Sinalização YAP/antagonistas & inibidores , Proteínas de Sinalização YAP/metabolismo
2.
Cell ; 151(7): 1443-56, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23245942

RESUMO

Wnt growth factors are fundamental regulators of cell fate, but how the Wnt signal is translated into biological responses is incompletely understood. Here, we report that TAZ, a biologically potent transcriptional coactivator, serves as a downstream element of the Wnt/ß-catenin cascade. This function of TAZ is independent from its well-established role as mediator of Hippo signaling. In the absence of Wnt activity, the components of the ß-catenin destruction complex--APC, Axin, and GSK3--are also required to keep TAZ at low levels. TAZ degradation depends on phosphorylated ß-catenin that bridges TAZ to its ubiquitin ligase ß-TrCP. Upon Wnt signaling, escape of ß-catenin from the destruction complex impairs TAZ degradation and leads to concomitant accumulation of ß-catenin and TAZ. At the genome-wide level, a substantial portion of Wnt transcriptional responses is mediated by TAZ. TAZ activation is a general feature of Wnt signaling and is functionally relevant to mediate Wnt biological effects.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Via de Sinalização Wnt , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Linhagem Celular , Linhagem Celular Tumoral , Quinase 3 da Glicogênio Sintase/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Células-Tronco Mesenquimais/metabolismo , Camundongos , Proteólise , Transativadores , Fatores de Transcrição , Proteínas com Motivo de Ligação a PDZ com Coativador Transcricional , beta Catenina/metabolismo , gama Catenina/metabolismo
3.
Mol Cell ; 76(3): 453-472.e8, 2019 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-31519520

RESUMO

MYOD-directed fibroblast trans-differentiation into skeletal muscle provides a unique model to investigate how one transcription factor (TF) reconfigures the three-dimensional chromatin architecture to control gene expression, which is otherwise achieved by the combinatorial activities of multiple TFs. Integrative analysis of genome-wide high-resolution chromatin interactions, MYOD and CTCF DNA-binding profile, and gene expression, revealed that MYOD directs extensive re-wiring of interactions involving cis-regulatory and structural genomic elements, including promoters, enhancers, and insulated neighborhoods (INs). Re-configured INs were hot-spots of differential interactions, whereby MYOD binding to highly constrained sequences at IN boundaries and/or inside INs led to alterations of promoter-enhancer interactions to repress cell-of-origin genes and to activate muscle-specific genes. Functional evidence shows that MYOD-directed re-configuration of chromatin interactions temporally preceded the effect on gene expression and was mediated by direct MYOD-DNA binding. These data illustrate a model whereby a single TF alters multi-loop hubs to drive somatic cell trans-differentiation.


Assuntos
Transdiferenciação Celular , Reprogramação Celular , Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Fibroblastos/metabolismo , Desenvolvimento Muscular , Proteína MyoD/metabolismo , Mioblastos Esqueléticos/metabolismo , Animais , Sítios de Ligação , Linhagem Celular , Transdiferenciação Celular/genética , Cromatina/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Camundongos , Desenvolvimento Muscular/genética , Proteína MyoD/genética , Conformação de Ácido Nucleico , Fenótipo , Ligação Proteica , Relação Estrutura-Atividade , Transcrição Gênica
4.
Cell ; 147(4): 759-72, 2011 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-22078877

RESUMO

Cancer stem cells (CSCs) are proposed to drive tumor initiation and progression. Yet, our understanding of the cellular and molecular mechanisms that underlie CSC properties is limited. Here we show that the activity of TAZ, a transducer of the Hippo pathway, is required to sustain self-renewal and tumor-initiation capacities in breast CSCs. TAZ protein levels and activity are elevated in prospective CSCs and in poorly differentiated human tumors and have prognostic value. Gain of TAZ endows self-renewal capacity to non-CSCs. In epithelial cells, TAZ forms a complex with the cell-polarity determinant Scribble, and loss of Scribble--or induction of the epithelial-mesenchymal transition (EMT)--disrupts the inhibitory association of TAZ with the core Hippo kinases MST and LATS. This study links the CSC concept to the Hippo pathway in breast cancer and reveals a mechanistic basis of the control of Hippo kinases by cell polarity.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Células-Tronco Neoplásicas/patologia , Transdução de Sinais , Fatores de Transcrição/metabolismo , Aciltransferases , Polaridade Celular , Transição Epitelial-Mesenquimal , Feminino , Humanos , Proteínas de Membrana/metabolismo , Metástase Neoplásica/patologia , Células-Tronco Neoplásicas/metabolismo , Proteínas Supressoras de Tumor/metabolismo
5.
EMBO J ; 39(9): e102209, 2020 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-32157726

RESUMO

HIV-1 persists in a latent form during antiretroviral therapy, mainly in CD4+ T cells, thus hampering efforts for a cure. HIV-1 infection is accompanied by metabolic alterations, such as oxidative stress, but the effect of cellular antioxidant responses on viral replication and latency is unknown. Here, we show that cells survive retroviral replication, both in vitro and in vivo in SIVmac-infected macaques, by upregulating antioxidant pathways and the intertwined iron import pathway. These changes are associated with remodeling of promyelocytic leukemia protein nuclear bodies (PML NBs), an important constituent of nuclear architecture and a marker of HIV-1 latency. We found that PML NBs are hyper-SUMOylated and that PML protein is degraded via the ubiquitin-proteasome pathway in productively infected cells, before latency establishment and after reactivation. Conversely, normal numbers of PML NBs were restored upon transition to latency or by decreasing oxidative stress or iron content. Our results highlight antioxidant and iron import pathways as determinants of HIV-1 latency and support their pharmacologic inhibition as tools to regulate PML stability and impair latency establishment.


Assuntos
Redes Reguladoras de Genes , Infecções por HIV/virologia , HIV-1/fisiologia , Ferro/metabolismo , Proteína da Leucemia Promielocítica/metabolismo , Animais , Linhagem Celular , Modelos Animais de Doenças , Infecções por HIV/genética , Infecções por HIV/metabolismo , Humanos , Macaca , Oxirredução , Proteólise , Análise de Sequência de RNA , Sumoilação , Regulação para Cima , Latência Viral
6.
Brief Bioinform ; 22(1): 20-29, 2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-32363378

RESUMO

Recent advances in single-cell technologies are providing exciting opportunities for dissecting tissue heterogeneity and investigating cell identity, fate and function. This is a pristine, exploding field that is flooding biologists with a new wave of data, each with its own specificities in terms of complexity and information content. The integrative analysis of genomic data, collected at different molecular layers from diverse cell populations, holds promise to address the full-scale complexity of biological systems. However, the combination of different single-cell genomic signals is computationally challenging, as these data are intrinsically heterogeneous for experimental, technical and biological reasons. Here, we describe the computational methods for the integrative analysis of single-cell genomic data, with a focus on the integration of single-cell RNA sequencing datasets and on the joint analysis of multimodal signals from individual cells.


Assuntos
Biologia Computacional/métodos , RNA-Seq/métodos , Análise de Célula Única/métodos , Animais , Humanos
7.
Haematologica ; 107(5): 1131-1143, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-34162177

RESUMO

Enhancers are regulatory regions of DNA, which play a key role in cell-type specific differentiation and development. Most active enhancers are transcribed into enhancer RNA (eRNA) that can regulate transcription of target genes by means of in cis as well as in trans action. eRNA stabilize contacts between distal genomic regions and mediate the interaction of DNA with master transcription factors. Here, we characterized an enhancer eRNA, GECPAR (germinal center proliferative adapter RNA), which is specifically transcribed in normal and neoplastic germinal center B cells from the super-enhancer of POU2AF1, a key regulatory gene of the germinal center reaction. Using diffuse large B-cell lymphoma cell line models, we demonstrated the tumor suppressor activity of GECPAR, which is mediated via its transcriptional regulation of proliferation and differentiation genes, particularly MYC and the Wnt pathway.


Assuntos
Elementos Facilitadores Genéticos , Linfoma Difuso de Grandes Células B , Humanos , Linfoma Difuso de Grandes Células B/genética , RNA/genética , RNA não Traduzido , Transcrição Gênica
8.
Cell Mol Life Sci ; 79(1): 28, 2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-34936031

RESUMO

Microgravity and space radiation (SR) are two highly influential factors affecting humans in space flight (SF). Many health problems reported by astronauts derive from endothelial dysfunction and impaired homeostasis. Here, we describe the adaptive response of human, capillary endothelial cells to SF. Reference samples on the ground and at 1g onboard permitted discrimination between the contribution of microgravity and SR within the combined responses to SF. Cell softening and reduced motility occurred in SF cells, with a loss of actin stress fibers and a broader distribution of microtubules and intermediate filaments within the cytoplasm than in control cells. Furthermore, in space the number of primary cilia per cell increased and DNA repair mechanisms were found to be activated. Transcriptomics revealed the opposing effects of microgravity from SR for specific molecular pathways: SR, unlike microgravity, stimulated pathways for endothelial activation, such as hypoxia and inflammation, DNA repair and apoptosis, inhibiting autophagic flux and promoting an aged-like phenotype. Conversely, microgravity, unlike SR, activated pathways for metabolism and a pro-proliferative phenotype. Therefore, we suggest microgravity and SR should be considered separately to tailor effective countermeasures to protect astronauts' health.


Assuntos
Autofagia , Capilares/citologia , Radiação Cósmica , Células Endoteliais/efeitos da radiação , Transdução de Sinais , Ausência de Peso , Apoptose , Biomarcadores/metabolismo , Linhagem Celular , Sobrevivência Celular , Cromossomos Humanos/metabolismo , Citoesqueleto/metabolismo , Dano ao DNA , Fluorescência , Regulação da Expressão Gênica , Genoma Humano , Humanos , Masculino , Mecanotransdução Celular , Modelos Biológicos , Transdução de Sinais/efeitos da radiação , Voo Espacial , Estresse Fisiológico , Homeostase do Telômero , Transcriptoma/genética
9.
J Hepatol ; 75(2): 351-362, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33741397

RESUMO

BACKGROUND & AIMS: About 15% of intrahepatic cholangiocarcinomas (iCCAs) express fibroblast growth factor receptor 2 (FGFR2) fusion proteins (FFs), usually alongside mutational inactivation of TP53, CDKN2A or BAP1. In FFs, FGFR2 residues 1-768 fuse to sequences encoded by a diverse array of partner genes (>60) causing oncogenic FF activation. While FGFR-specific tyrosine kinase inhibitors (F-TKI) provide clinical benefit in FF+ iCCA, responses are partial and/or limited by resistance mechanisms, such as the V565F substitution in the FGFR2 gatekeeper residue. Improving on FF targeting in iCCA therefore remains a critical unmet need. Herein, we aimed to generate a murine model of FF-driven iCCA and use this to uncover actionable FF-associated dependencies. METHODS: Four iCCA FFs carrying different fusion sequences were expressed in Tp53-/- mouse liver organoids. Tumorigenic properties of genetically modified liver organoids were assessed by transplantation into immuno-deficient mice. Cellular models derived from neoplastic lesions were exploited for pre-clinical studies. RESULTS: Transplantation of FF-expressing liver organoids yielded tumors diagnosed as CCA based on histological, phenotypic and transcriptomic analyses. The penetrance of this tumorigenic phenotype was influenced by FF identity. Tumor organoids and 2D cell lines derived from CCA lesions were addicted to FF signaling via Ras-Erk, regardless of FF identity or V565F mutation. Dual blockade of FF and the Ras-Erk pathway by concomitant pharmacological inhibition of FFs and Mek1/2 provided greater therapeutic efficacy than single agent F-TKI in vitro and in vivo. CONCLUSIONS: FF-driven iCCA pathogenesis was successfully modeled on a Tp53-/- murine background, revealing biological heterogeneity among structurally different FFs. Double blockade of FF-ERK signaling deserves consideration for precision-based approaches against human FF+ iCCA. LAY SUMMARY: Intrahepatic cholangiocarcinoma (iCCA) is a rare cancer that is difficult to treat. A subtype of iCCA is caused by genomic alterations that generate oncogenic drivers known as FGFR2 fusions. Patients with FGFR2 fusions respond to FGFR inhibitors, but clinical responses are often of modest duration. We used animal and cellular models to show that FGFR2 fusions require the activity of a downstream effector named Mek1/2. We found that dual blockade of FGFR2 fusions and Mek1/2 was more effective than isolated inhibition of FGFR2 fusions, pointing to the potential clinical utility of dual FGFR2-MEK1/2 blockade in patients with iCCA.


Assuntos
Colangiocarcinoma/etiologia , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/antagonistas & inibidores , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Proteína Supressora de Tumor p53/efeitos dos fármacos , Análise de Variância , Animais , Linhagem Celular/metabolismo , Colangiocarcinoma/genética , Modelos Animais de Doenças , Camundongos , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/efeitos dos fármacos
10.
Bioinformatics ; 36(7): 2266-2268, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31778141

RESUMO

SUMMARY: Here we present APTANI2, an expanded and optimized version of APTANI, a computational tool for selecting target-specific aptamers from high-throughput-Systematic Evolution of Ligands by Exponential Enrichment data through sequence-structure analysis. As compared to its original implementation, APTANI2 ranks aptamers and identifies relevant structural motifs through the calculation of a score that combines frequency and structural stability of each secondary structure predicted in any aptamer sequence. In addition, APTANI2 comprises modules for a deeper investigation of sequence motifs and secondary structures, a graphical user interface that enhances its usability, and coding solutions that improve performances. AVAILABILITY AND IMPLEMENTATION: Source code, documentation and example command lines can be downloaded from http://aptani.unimore.it. APTANI2 is implemented in Python 3.4, released under the GNU GPL3.0 License, and compatible with Linux, Mac OS and the MS Windows subsystem for Linux. SUPPLEMENTARY INFORMATION: Supplementary information is available at Bioinformatics online.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Software , Documentação
11.
Nat Mater ; 19(7): 797-806, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32066931

RESUMO

Defining the interplay between the genetic events and microenvironmental contexts necessary to initiate tumorigenesis in normal cells is a central endeavour in cancer biology. We found that receptor tyrosine kinase (RTK)-Ras oncogenes reprogram normal, freshly explanted primary mouse and human cells into tumour precursors, in a process requiring increased force transmission between oncogene-expressing cells and their surrounding extracellular matrix. Microenvironments approximating the normal softness of healthy tissues, or blunting cellular mechanotransduction, prevent oncogene-mediated cell reprogramming and tumour emergence. However, RTK-Ras oncogenes empower a disproportional cellular response to the mechanical properties of the cell's environment, such that when cells experience even subtle supra-physiological extracellular-matrix rigidity they are converted into tumour-initiating cells. These regulations rely on YAP/TAZ mechanotransduction, and YAP/TAZ target genes account for a large fraction of the transcriptional responses downstream of oncogenic signalling. This work lays the groundwork for exploiting oncogenic mechanosignalling as a vulnerability at the onset of tumorigenesis, including tumour prevention strategies.


Assuntos
Reprogramação Celular/fisiologia , Matriz Extracelular/fisiologia , Oncogenes/fisiologia , Animais , Fenômenos Biomecânicos , Linhagem Celular Tumoral , Feminino , Regulação da Expressão Gênica , Humanos , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/metabolismo , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Microscopia/métodos , Oncogenes/genética , Pâncreas/citologia , Análise de Sequência de RNA
13.
Nat Methods ; 14(7): 679-685, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28604721

RESUMO

Hi-C is a genome-wide sequencing technique used to investigate 3D chromatin conformation inside the nucleus. Computational methods are required to analyze Hi-C data and identify chromatin interactions and topologically associating domains (TADs) from genome-wide contact probability maps. We quantitatively compared the performance of 13 algorithms in their analyses of Hi-C data from six landmark studies and simulations. This comparison revealed differences in the performance of methods for chromatin interaction identification, but more comparable results for TAD detection between algorithms.


Assuntos
Mapeamento Cromossômico/métodos , Cromossomos/química , Biologia Computacional/métodos , Estudo de Associação Genômica Ampla/métodos , Animais , Cromatina/química , Cromossomos/genética , Simulação por Computador , Genoma
14.
Nucleic Acids Res ; 46(W1): W148-W156, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29800349

RESUMO

Several major screenings of genetic profiling and drug testing in cancer cell lines proved that the integration of genomic portraits and compound activities is effective in discovering new genetic markers of drug sensitivity and clinically relevant anticancer compounds. Despite most genetic and drug response data are publicly available, the availability of user-friendly tools for their integrative analysis remains limited, thus hampering an effective exploitation of this information. Here, we present GDA, a web-based tool for Genomics and Drugs integrated Analysis that combines drug response data for >50 800 compounds with mutations and gene expression profiles across 73 cancer cell lines. Genomic and pharmacological data are integrated through a modular architecture that allows users to identify compounds active towards cancer cell lines bearing a specific genomic background and, conversely, the mutational or transcriptional status of cells responding or not-responding to a specific compound. Results are presented through intuitive graphical representations and supplemented with information obtained from public repositories. As both personalized targeted therapies and drug-repurposing are gaining increasing attention, GDA represents a resource to formulate hypotheses on the interplay between genomic traits and drug response in cancer. GDA is freely available at http://gda.unimore.it/.


Assuntos
Antineoplásicos/farmacologia , Genômica/métodos , Software , Linhagem Celular Tumoral , Humanos , Internet , Mutação , Neoplasias/genética , Neoplasias/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Transdução de Sinais , Ativação Transcricional , Transcriptoma/efeitos dos fármacos
15.
J Hepatol ; 71(1): 130-142, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30878582

RESUMO

BACKGROUND & AIMS: In vitro, cell function can be potently regulated by the mechanical properties of cells and of their microenvironment. Cells measure these features by developing forces via their actomyosin cytoskeleton, and respond accordingly by regulating intracellular pathways, including the transcriptional coactivators YAP/TAZ. Whether mechanical cues are relevant for in vivo regulation of adult organ homeostasis, and whether this occurs through YAP/TAZ, remains largely unaddressed. METHODS: We developed Capzb conditional knockout mice and obtained primary fibroblasts to characterize the role of CAPZ in vitro. In vivo functional analyses were carried out by inducing Capzb inactivation in adult hepatocytes, manipulating YAP/Hippo activity by hydrodynamic tail vein injections, and treating mice with the ROCK inhibitor, fasudil. RESULTS: We found that the F-actin capping protein CAPZ restrains actomyosin contractility: Capzb inactivation alters stress fiber and focal adhesion dynamics leading to enhanced myosin activity, increased traction forces, and increased liver stiffness. In vitro, this rescues YAP from inhibition by a small cellular geometry; in vivo, it induces YAP activation in parallel to the Hippo pathway, causing extensive hepatocyte proliferation and leading to striking organ overgrowth. Moreover, Capzb is required for the maintenance of the differentiated hepatocyte state, for metabolic zonation, and for gluconeogenesis. In keeping with changes in tissue mechanics, inhibition of the contractility regulator ROCK, or deletion of the Yap1 mechanotransducer, reverse the phenotypes emerging in Capzb-null livers. CONCLUSIONS: These results indicate a previously unsuspected role for CAPZ in tuning the mechanical properties of cells and tissues, which is required in hepatocytes for the maintenance of the differentiated state and to regulate organ size. More generally, it indicates for the first time that mechanotransduction has a physiological role in maintaining liver homeostasis in mammals. LAY SUMMARY: The mechanical properties of cells and tissues (i.e. whether they are soft or stiff) are thought to be important regulators of cell behavior. Herein, we found that inactivation of the protein CAPZ alters the mechanical properties of cells and liver tissues, leading to YAP hyperactivation. In turn, this profoundly alters liver physiology, causing organ overgrowth, defects in liver cell differentiation and metabolism. These results reveal a previously uncharacterized role for mechanical signals in the maintenance of adult liver homeostasis.


Assuntos
Actinas/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteína de Capeamento de Actina CapZ/metabolismo , Proteínas de Ciclo Celular/metabolismo , Hepatócitos/fisiologia , Fígado , Mecanotransdução Celular/fisiologia , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Células Cultivadas , Elasticidade , Via de Sinalização Hippo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Fígado/fisiopatologia , Camundongos , Camundongos Knockout , Transdução de Sinais , Proteínas de Sinalização YAP
16.
EMBO J ; 34(10): 1349-70, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25796446

RESUMO

Increased glucose metabolism and reprogramming toward aerobic glycolysis are a hallmark of cancer cells, meeting their metabolic needs for sustained cell proliferation. Metabolic reprogramming is usually considered as a downstream consequence of tumor development and oncogene activation; growing evidence indicates, however, that metabolism on its turn can support oncogenic signaling to foster tumor malignancy. Here, we explored how glucose metabolism regulates gene transcription and found an unexpected link with YAP/TAZ, key transcription factors regulating organ growth, tumor cell proliferation and aggressiveness. When cells actively incorporate glucose and route it through glycolysis, YAP/TAZ are fully active; when glucose metabolism is blocked, or glycolysis is reduced, YAP/TAZ transcriptional activity is decreased. Accordingly, glycolysis is required to sustain YAP/TAZ pro-tumorigenic functions, and YAP/TAZ are required for the full deployment of glucose growth-promoting activity. Mechanistically we found that phosphofructokinase (PFK1), the enzyme regulating the first committed step of glycolysis, binds the YAP/TAZ transcriptional cofactors TEADs and promotes their functional and biochemical cooperation with YAP/TAZ. Strikingly, this regulation is conserved in Drosophila, where phosphofructokinase is required for tissue overgrowth promoted by Yki, the fly homologue of YAP. Moreover, gene expression regulated by glucose metabolism in breast cancer cells is strongly associated in a large dataset of primary human mammary tumors with YAP/TAZ activation and with the progression toward more advanced and malignant stages. These findings suggest that aerobic glycolysis endows cancer cells with particular metabolic properties and at the same time sustains transcription factors with potent pro-tumorigenic activities such as YAP/TAZ.


Assuntos
Bactérias Aeróbias/metabolismo , Fatores de Transcrição/metabolismo , Aciltransferases , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Linhagem Celular Tumoral , Imunoprecipitação da Cromatina , Drosophila , Glicólise/genética , Glicólise/fisiologia , Humanos , Imunoprecipitação , Fosfoproteínas/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Proteínas de Sinalização YAP
17.
EMBO Rep ; 18(8): 1331-1351, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28652379

RESUMO

The abundant, nuclear-retained, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been associated with a poorly differentiated and aggressive phenotype of mammary carcinomas. This long non-coding RNA (lncRNA) localizes to nuclear speckles, where it interacts with a subset of splicing factors and modulates their activity. In this study, we demonstrate that oncogenic splicing factor SRSF1 bridges MALAT1 to mutant p53 and ID4 proteins in breast cancer cells. Mutant p53 and ID4 delocalize MALAT1 from nuclear speckles and favor its association with chromatin. This enables aberrant recruitment of MALAT1 on VEGFA pre-mRNA and modulation of VEGFA isoforms expression. Interestingly, VEGFA-dependent expression signatures associate with ID4 expression specifically in basal-like breast cancers carrying TP53 mutations. Our results highlight a key role for MALAT1 in control of VEGFA isoforms expression in breast cancer cells expressing gain-of-function mutant p53 and ID4 proteins.


Assuntos
Neoplasias da Mama/fisiopatologia , Proteínas Inibidoras de Diferenciação/metabolismo , RNA Longo não Codificante/genética , Proteína Supressora de Tumor p53/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Neoplasias da Mama/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Inibidoras de Diferenciação/genética , Mutação , Neovascularização Patológica , Isoformas de Proteínas/metabolismo , Splicing de RNA , Fatores de Processamento de Serina-Arginina/genética , Proteína Supressora de Tumor p53/genética , Fator A de Crescimento do Endotélio Vascular/biossíntese
18.
BMC Genomics ; 19(1): 302, 2018 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-29703138

RESUMO

BACKGROUND: Emissions from diesel vehicles and biomass burning are the principal sources of primary ultrafine particles (UFP). The exposure to UFP has been associated to cardiovascular and pulmonary diseases, including lung cancer. Although many aspects of the toxicology of ambient particulate matter (PM) have been unraveled, the molecular mechanisms activated in human cells by the exposure to UFP are still poorly understood. Here, we present an RNA-seq time-course experiment (five time point after single dose exposure) used to investigate the differential and temporal changes induced in the gene expression of human bronchial epithelial cells (BEAS-2B) by the exposure to UFP generated from diesel and biomass combustion. A combination of different bioinformatics tools (EdgeR, next-maSigPro and reactome FI app-Cytoscape and prioritization strategies) facilitated the analyses the temporal transcriptional pattern, functional gene set enrichment and gene networks related to cellular response to UFP particles. RESULTS: The bioinformatics analysis of transcriptional data reveals that the two different UFP induce, since the earliest time points, different transcriptional dynamics resulting in the activation of specific genes. The functional enrichment of differentially expressed genes indicates that the exposure to diesel UFP induces the activation of genes involved in TNFα signaling via NF-kB and inflammatory response, and hypoxia. Conversely, the exposure to ultrafine particles from biomass determines less distinct modifications of the gene expression profiles. Diesel UFP exposure induces the secretion of biomarkers associated to inflammation (CCXL2, EPGN, GREM1, IL1A, IL1B, IL6, IL24, EREG, VEGF) and transcription factors (as NFE2L2, MAFF, HES1, FOSL1, TGIF1) relevant for cardiovascular and lung disease. By means of network reconstruction, four genes (STAT3, HIF1a, NFKB1, KRAS) have emerged as major regulators of transcriptional response of bronchial epithelial cells exposed to diesel exhaust. CONCLUSIONS: Overall, this work highlights modifications of the transcriptional landscape in human bronchial cells exposed to UFP and sheds new lights on possible mechanisms by means of which UFP acts as a carcinogen and harmful factor for human health.


Assuntos
Biomassa , Brônquios/metabolismo , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Material Particulado/efeitos adversos , Emissões de Veículos/intoxicação , Brônquios/citologia , Brônquios/efeitos dos fármacos , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Humanos , Transcriptoma
19.
Nature ; 487(7407): 380-4, 2012 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-22801492

RESUMO

The molecular determinants of malignant cell behaviours in breast cancer remain only partially understood. Here we show that SHARP1 (also known as BHLHE41 or DEC2) is a crucial regulator of the invasive and metastatic phenotype in triple-negative breast cancer (TNBC), one of the most aggressive types of breast cancer. SHARP1 is regulated by the p63 metastasis suppressor and inhibits TNBC aggressiveness through inhibition of hypoxia-inducible factor 1α (HIF-1α) and HIF-2α (HIFs). SHARP1 opposes HIF-dependent TNBC cell migration in vitro, and invasive or metastatic behaviours in vivo. SHARP1 is required, and sufficient, to limit expression of HIF-target genes. In primary TNBC, endogenous SHARP1 levels are inversely correlated with those of HIF targets. Mechanistically, SHARP1 binds to HIFs and promotes HIF proteasomal degradation by serving as the HIF-presenting factor to the proteasome. This process is independent of pVHL (von Hippel-Lindau tumour suppressor), hypoxia and the ubiquitination machinery. SHARP1 therefore determines the intrinsic instability of HIF proteins to act in parallel to, and cooperate with, oxygen levels. This work sheds light on the mechanisms and pathways by which TNBC acquires invasiveness and metastatic propensity.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Regulação Neoplásica da Expressão Gênica , Metástase Neoplásica , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Ciclina G2/genética , Feminino , Humanos , Estimativa de Kaplan-Meier , Análise Multivariada
20.
Carcinogenesis ; 38(1): 64-75, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27797825

RESUMO

Lung cancer is the first cause of cancer death worldwide and the Hippo pathway transcriptional coactivators YAP/TAZ have a pro-oncogenic role in this context. In order to understand the mechanisms through which YAP/TAZ elicit their oncogenic role in different systems, many studies are focused on YAP/TAZ target genes involved in the regulation of cell proliferation/survival and migration. However, there is scarce evidence on the role of YAP/TAZ in microRNA regulation while there is increasing evidence supporting the role of microRNAs in the main oncogenic processes. Here, we showed that YAP/TAZ were able to regulate several microRNAs in non-small cell lung cancer (NSCLC) cell lines. In detail, we focused on a cluster of three oncogenic microRNAs (miR-25, 93 and 106b) hosted in the MCM7 gene that were overexpressed in lung tumors compared to normal tissues. In addition, similar behavior was observed in breast cancer and head and neck tumor casuistries, where they showed a prognostic role. In NSCLC cells, YAP/TAZ induced the transcription of the MCM7 gene and its hosted miRs, thereby promoting cell proliferation through the post-transcriptional inhibition of the p21 cell cycle regulator. Accordingly, p21 was maintained at low levels in lung tumors compared to normal tissues. Conversely, its expression was restored in NSCLC cells upon YAP/TAZ interference or upon treatment with the statin cerivastatin. In summary, we provide evidence for a novel mechanism of modulation supporting the protumorigenic functions of the YAP/TAZ factors through the modulation of a bioncogenic locus consisting of one gene and three hosted microRNAs.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Carcinogênese/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , MicroRNAs/genética , Componente 7 do Complexo de Manutenção de Minicromossomo/metabolismo , Fosfoproteínas/metabolismo , Fatores de Transcrição/metabolismo , Aciltransferases , Proteínas Adaptadoras de Transdução de Sinal/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Componente 7 do Complexo de Manutenção de Minicromossomo/genética , Fosfoproteínas/genética , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Proteínas de Sinalização YAP
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