Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56.971
Filtrar
1.
Plant Mol Biol ; 102(3): 307-322, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31902068

RESUMEN

KEY MESSAGE: MEM1 participates in ROS1-mediated DNA demethylation pathway, and acts functionally as ROS3 to counteract the effects of RdDM pathway.mem1mutation leads to large numbers of hyper-DMRs inArabidopsisgenome. In higher plants, DNA methylation performs important functions in silencing transcribed genes and transposable elements (TEs). Active DNA demethylation mediated by REPRESSOR OF SILENCING 1 (ROS1) is able to antagonize the action of DNA methylation caused by RNA-directed DNA methylation (RdDM) pathway, which plays critical roles in keeping DNA methylation at a proper level. In this study, a new mutant named mem1 (for methylation elevated mutant 1) was isolated from a genetic screen of T-DNA insertional mutant population for lines with elevated DNA methylation at a particular locus through Chop-PCR method. MEM1 possesses a Zf-C3HC domain, and is localized in nucleus as well as highly expressed in cotyledons. Whole-genome bisulfite sequencing data showed that knockout mutation of MEM1 leads to 4519 CG, 1793 CHG and 12739 CHH hyper-DMRs (for differentially methylated regions). Further analysis indicated that there are 2751, 2216 and 2042 overlapped CG hyper-DMRs between mem1-1and three mutants, i.e. ros1-4, rdd and ros3-2, respectively; 797, 2514, and 6766 overlapped CHH hyper-DMRs were observed between mem1-1 and three such mutants, respectively; mem1 nrpd1-3 and mem1 rdm1 double mutants showed nearly complete or partial loss of hypermethylation at 4 tested loci, suggesting that MEM1 performs similar functions as DNA glycosylase/lyases in counteracting excessive DNA methylation, and MEM1 plays important roles as REPRESSOR OF SILENCING 3 (ROS3) in erasing CHH methylation caused by the RdDM pathway. Together, these data demonstrate the involvement of MEM1 in ROS1-mediated DNA demethylation pathway and functional connections between MEM1 and ROS3.


Asunto(s)
Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/metabolismo , Desmetilación del ADN , Núcleo Celular/metabolismo , Metilación de ADN , Elementos Transponibles de ADN , Técnicas de Silenciamiento del Gen , Silenciador del Gen , Genoma de Planta , Mutación/genética , Proteínas Nucleares/genética , Filogenia , Plantas Modificadas Genéticamente , Proteínas de Unión al ARN
2.
Adv Exp Med Biol ; 1232: 271-276, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31893420

RESUMEN

Adaptation to hypoxia is essential for regulating the survival and functions of hypoxic cells; it is mainly mediated by the hypoxia-inducible factor 1 (HIF1). The alpha subunit of HIF1 (HIF1α) is a well-known regulatory component of HIF1, which is tightly controlled by various types of HIF1α-regulating processes. Previous research has shown that microtubule-regulated HIF1α nuclear translocation is a key factor for HIF1 activation under hypoxia. In this review, we summarize experimental reports on the role of microtubule-associated factors, such as microtubule, dynein, and dynein adaptor protein, in nuclear translocation of HIF1α. Based upon scientific evidence, we propose a bicaudal D homolog (BICD) as a novel HIF1α translocation regulating factor. A deeper understanding of the mechanism of the action of regulatory factors in controlling HIF1α nuclear translocation will provide novel insights into cell biology under hypoxia.


Asunto(s)
Transporte Activo de Núcleo Celular , Subunidad alfa del Factor 1 Inducible por Hipoxia , Transporte Activo de Núcleo Celular/genética , Hipoxia de la Célula/fisiología , Núcleo Celular/metabolismo , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Microtúbulos/metabolismo , Transporte de Proteínas/genética
3.
Toxicol Lett ; 319: 256-263, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31639410

RESUMEN

Transcription factor activator protein (AP)-1 can be activated in nitrogen-mustard-injured mouse skin, and is thought to participate in the inflammatory response. AP-1 consists of homo- or heterodimers of Fos [c-Fos, Fos-B, fos-related antigen (Fra)-1 and Fra-2] and Jun (c-Jun, JunB and JunD) family members, and information about their expression, location and function are still unclear. In nitrogen-mustard-exposed mouse skin, we found p-ERK activation increased Fra-1 and FosB. Unlike the nucleus location of c-Fos and FosB, Fra-1 and Fra-2 were mainly expressed in the cytoplasm. In nitrogen-mustard-exposed cultured immortalized human keratinocytes (HaCaT cells), Fra-1 in the nucleus functioned as an inhibitor of inflammatory cytokine interleukin (IL)-8. Co-immunoprecipitation showed that Fra-1 formed dimers with IL-8 transcription factors c-Jun, JunB and JunD. Fra-1 depletion increased c-Fos and FosB in the nucleus, accompanied by increased heterodimers of c-Fos/c-Jun, c-Fos/JunB, c-Fos/JunD, and FosB/JunB. In conclusion, Fra-1 trapped in the cytoplasm after nitrogen mustard exposure might be a driving force for IL-8 over-expression in injured skin.


Asunto(s)
Sustancias para la Guerra Química/toxicidad , Epidermis/lesiones , Epidermis/metabolismo , Interleucina-8/biosíntesis , Mecloretamina/toxicidad , Proteínas Proto-Oncogénicas c-fos/metabolismo , Animales , Línea Celular , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Citoplasma/efectos de los fármacos , Citoplasma/metabolismo , Humanos , Queratinocitos/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Masculino , Ratones , Ratones Pelados , ARN Interferente Pequeño/farmacología
5.
Genes Dev ; 34(1-2): 53-71, 2020 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-31857346

RESUMEN

Hippo signaling controls organ size and tumor progression through a conserved pathway leading to nuclear translocation of the transcriptional effector Yki/Yap/Taz. Most of our understanding of Hippo signaling pertains to its cytoplasmic regulation, but how the pathway is controlled in the nucleus remains poorly understood. Here we uncover an evolutionarily conserved mechanism by which CDK7 promotes Yki/Yap/Taz stabilization in the nucleus to sustain Hippo pathway outputs. We found that a modular E3 ubiquitin ligase complex CRL4DCAF12 binds and targets Yki/Yap/Taz for ubiquitination and degradation, whereas CDK7 phosphorylates Yki/Yap/Taz at S169/S128/S90 to inhibit CRL4DCAF12 recruitment, leading to Yki/Yap/Taz stabilization. As a consequence, inactivation of CDK7 reduced organ size and inhibited tumor growth, which could be reversed by restoring Yki/Yap activity. Our study identifies an unanticipated layer of Hippo pathway regulation, defines a novel mechanism by which CDK7 regulates tissue growth, and implies CDK7 as a drug target for Yap/Taz-driven cancer.


Asunto(s)
Carcinogénesis/genética , Quinasas Ciclina-Dependientes/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/enzimología , Drosophila melanogaster/metabolismo , Proteínas Nucleares/metabolismo , Transactivadores/metabolismo , Animales , Antineoplásicos/farmacología , Carcinogénesis/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Núcleo Celular/metabolismo , Quinasas Ciclina-Dependientes/genética , Drosophila melanogaster/genética , Activación Enzimática , Regulación Neoplásica de la Expresión Génica/genética , Técnicas de Silenciamiento del Gen , Humanos , Neoplasias Hepáticas/enzimología , Neoplasias Hepáticas/fisiopatología , Ratones , Tamaño de los Órganos/genética , Fenilendiaminas/farmacología , Proteolisis , Pirimidinas/farmacología
6.
Int J Cancer ; 146(2): 577-588, 2020 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-31271443

RESUMEN

The Mediator complex is a transcriptional regulator interacting with transcription factors and RNA-polymerase-II. Recently, we identified its subunit CDK19 to be specifically expressed in prostate cancer (PCa) and to be functionally implicated in PCa aggressiveness. Aim of our study was to comprehensively characterize the protein expression of CDK19 and its paralog CDK8 in PCa. We performed immunohistochemistry (IHC) for CDK19/CDK8 on a large cohort including needle biopsies from 202 patients, 799 primary tumor foci of radical prostatectomy specimens from 415 patients, 120 locally advanced tumor foci obtained by palliative transurethral resection, 140 lymph node metastases, 67 distant metastases and 82 benigns. Primary tumors were stained for the proliferation marker Ki67, androgen receptor (AR) and ERG. For 376 patients, clinic-pathologic data were available. Primary endpoint was disease-recurrence-free survival (DFS). Nuclear CDK19 and CDK8 expression increases during progression showing the highest intensity in metastatic and castration-resistant tumors. High CDK19 expression on primary tumors correlates with DFS independently from Gleason grade and PSA. Five-year-DFS rates of patients with primary tumors expressing no, moderate and high CDK19 are 73.7, 56.9 and 30.4%, respectively. CDK19 correlates with Gleason grade, T-stage, Ki67 proliferation-index, nuclear AR expression and ERG-status. Therapeutic options for metastatic and castration-resistant PCa remain limited. In the current study, we confirmed an important role of the Mediator subunit CDK19 in advanced PCa supporting current developments to target CDK19 and its paralog CDK8. Furthermore, CDK19 protein expression has the potential to predict disease recurrence independently from established biomarkers thus contributing to individual management for PCa patients.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Quinasa 8 Dependiente de Ciclina/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Recurrencia Local de Neoplasia/diagnóstico , Neoplasias de la Próstata/patología , Biopsia , Núcleo Celular/metabolismo , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Estudios de Seguimiento , Humanos , Estimación de Kaplan-Meier , Masculino , Clasificación del Tumor , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Pronóstico , Próstata/patología , Próstata/cirugía , Prostatectomía , Neoplasias de la Próstata/mortalidad , Neoplasias de la Próstata/cirugía
7.
Cancer Sci ; 111(2): 395-405, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31854049

RESUMEN

The onset of breast cancer among young patients is a major issue in cancer etiology. Our previous study has shown that poor prognosis in young women with breast cancer is associated with lower expression of the microRNA miR-1285-5p. In this study, we showed that the expression of miR-1285-5p is lower in tumor tissues than in normal tissues. Accumulating evidence suggests that miR-1285-5p plays critical roles in various types of cancers. However, the functional role of miR-1285-5p in breast cancer remains to be elucidated. Here, we showed the tumor-suppressive role of miR-1285-5p and detailed its mechanism of action in breast cancer. Overexpression of miR-1285-5p significantly inhibited cell proliferation in breast cancer cells regardless of the tumor subtype. Among the target genes of miR-1285-5p, we found that transmembrane protein 194A (TMEM194A) was directly regulated by miR-1285-5p. Notably, separation of centrosomes from the nuclear envelope was observed upon knockdown of TMEM194A or overexpression of miR-1285-5p. In conclusion, our findings show that miR-1285-5p is a tumor suppressor via TMEM194A inhibition in breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , MicroARNs/genética , Proteínas Nucleares/genética , Proteína de Unión al GTP ran/genética , Regiones no Traducidas 3' , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Núcleo Celular/metabolismo , Proliferación Celular , Centrosoma/metabolismo , Regulación hacia Abajo , Femenino , Regulación Neoplásica de la Expresión Génica , Humanos , Células MCF-7 , Proteínas Nucleares/metabolismo , Proteína de Unión al GTP ran/metabolismo
8.
Adv Exp Med Biol ; 1203: 1-31, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31811629

RESUMEN

mRNA is the "hermes" of gene expression as it carries the information of a protein-coding gene to the ribosome. Already during its synthesis, the mRNA is bound by mRNA-binding proteins that package the mRNA into a messenger ribonucleoprotein particle (mRNP). This mRNP assembly is important for mRNA stability and nuclear mRNA export. It also often regulates later steps in the mRNA lifetime such as translation and mRNA degradation in the cytoplasm. Thus, mRNP composition and accordingly the assembly of nuclear mRNA-binding proteins onto the mRNA are of crucial importance for correct gene expression. Here, we review our current knowledge of the mechanism of co-transcriptional mRNP assembly and nuclear mRNA export. We introduce the proteins involved and elaborate on what is known about their functions so far. In addition, we discuss the importance of regulated mRNP assembly in changing environmental conditions, especially during stress. Furthermore, we examine how defects in mRNP assembly cause diseases and how viruses exploit the host's nuclear mRNA export pathway. Finally, we summarize the questions that need to be answered in the future.


Asunto(s)
Transporte de ARN , Núcleo Celular/metabolismo , ARN Mensajero/metabolismo , Ribonucleoproteínas
9.
Adv Exp Med Biol ; 1203: 33-81, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31811630

RESUMEN

The process of creating a translation-competent mRNA is highly complex and involves numerous steps including transcription, splicing, addition of modifications, and, finally, export to the cytoplasm. Historically, much of the research on regulation of gene expression at the level of the mRNA has been focused on either the regulation of mRNA synthesis (transcription and splicing) or metabolism (translation and degradation). However, in recent years, the advent of new experimental techniques has revealed the export of mRNA to be a major node in the regulation of gene expression, and numerous large-scale and specific mRNA export pathways have been defined. In this chapter, we will begin by outlining the mechanism by which most mRNAs are homeostatically exported ("bulk mRNA export"), involving the recruitment of the NXF1/TAP export receptor by the Aly/REF and THOC5 components of the TREX complex. We will then examine various mechanisms by which this pathway may be controlled, modified, or bypassed in order to promote the export of subset(s) of cellular mRNAs, which include the use of metazoan-specific orthologs of bulk mRNA export factors, specific cis RNA motifs which recruit mRNA export machinery via specific trans-acting-binding factors, posttranscriptional mRNA modifications that act as "inducible" export cis elements, the use of the atypical mRNA export receptor, CRM1, and the manipulation or bypass of the nuclear pore itself. Finally, we will discuss major outstanding questions in the field of mRNA export heterogeneity and outline how cutting-edge experimental techniques are providing new insights into and tools for investigating the intriguing field of mRNA export heterogeneity.


Asunto(s)
Transporte de ARN , ARN Mensajero , Animales , Núcleo Celular/metabolismo , Regulación de la Expresión Génica , ARN Mensajero/metabolismo
10.
Anticancer Res ; 39(12): 6575-6583, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31810923

RESUMEN

BACKGROUND/AIM: The aim of this study was to examine whether the Wnt/ß-catenin signal activation is a cause of radioresistance in colon cancer by assessing the ß-catenin localization and its correlation with cancer stem cells (CSCs). MATERIALS AND METHODS: The nuclear levels of ß-catenin, the hallmark of Wnt activation, were analyzed in HCT116 and SW480 cells by immunohistochemistry, before and after irradiation. Further, we assessed CSC populations by staining for aldehyde dehydrogenase-1 (ALDH1) and CD44. RESULTS: ß-catenin was localized predominantly in the nucleus and plasma membrane in SW480 and HCT116 cells, respectively. Compared to HCT116 cells, SW480 cells displayed higher Wnt activation. At 24 h after irradiation, most of the DSBs in SW480 cells were repaired, but were still present in HCT116 cells. Additionally, compared to HCT116 cells, a significantly higher proportion of SW480 cells were ALDH1- and CD44-positive. CONCLUSION: Colon cancers with nuclear ß-catenin accumulation demonstrated greater radio-resistance with a higher number of CSCs.


Asunto(s)
Núcleo Celular/metabolismo , Neoplasias del Colon/metabolismo , Células Madre Neoplásicas/metabolismo , Tolerancia a Radiación , beta Catenina/metabolismo , /metabolismo , Línea Celular Tumoral , Membrana Celular/metabolismo , Células HCT116 , Humanos , Receptores de Hialuranos/metabolismo , Vía de Señalización Wnt
11.
Anticancer Res ; 39(12): 6711-6722, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31810936

RESUMEN

BACKGROUND/AIM: Autophagy is a cellular mechanism that recycles cellular components to maintain homeostasis. To investigate the clinical implication of autophagy in gastric cancer, the autophagy markers with autophagosome formation, LC3B and selective autophagy substrate p62/SQSTM1 (P62) were validated. MATERIALS AND METHODS: LC3B and p62 expression was examined using immunohistochemistry, western blot assays, and reverse-transcription polymerase chain reaction (RT-PCR). The relationship of LC3B and p62 expression in gastric adenocarcinomas with clinicopathological parameters, including patient survival, were analyzed. RESULTS: Normal gastric mucosae exhibit no LC3B and p62 expression, while tubular adenoma and gastric adenocarcinomas exhibit variable nuclear or cytoplasmic p62 expression. High LC3B, high cytoplasmic p62, and low nuclear p62 protein expression in gastric adenocarcinomas is positively correlated with poor prognostic factors including survival. CONCLUSION: Dynamic LC3B and p62 changes are suggested to be involved in gastric tumorigenesis and cancer progression. LC3B and p62 could be used as prognostic biomarkers and potential therapeutic targets for gastric adenocarcinomas.


Asunto(s)
Adenocarcinoma/metabolismo , Adenoma/metabolismo , Biomarcadores de Tumor/metabolismo , Proteínas Asociadas a Microtúbulos/metabolismo , Proteína Sequestosoma-1/metabolismo , Neoplasias Gástricas/metabolismo , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Adenoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Femenino , Mucosa Gástrica/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/patología , Adulto Joven
12.
Adv Exp Med Biol ; 1146: 117-130, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31612457

RESUMEN

As a cancer cell invades adjacent tissue, penetrates a basement membrane barrier, or squeezes into a blood capillary, its nucleus can be greatly constricted. Here, we examine: (1) the passive and active deformation of the nucleus during 3D migration; (2) the nuclear structures-namely, the lamina and chromatin-that govern nuclear deformability; (3) the effect of large nuclear deformation on DNA and nuclear factors; and (4) the downstream consequences of mechanically stressing the nucleus. We focus especially on recent studies showing that constricted migration causes nuclear envelope rupture and excess DNA damage, leading to cell cycle suppression, possibly cell death, and ultimately it seems to heritable genomic variation. We first review the latest understanding of nuclear dynamics during cell migration, and then explore the functional effects of nuclear deformation, especially in relation to genome integrity and potentially cancerous mutations.


Asunto(s)
Movimiento Celular , Núcleo Celular , Metástasis de la Neoplasia , Animales , Núcleo Celular/metabolismo , Cromatina , Humanos , Membrana Nuclear
13.
Mol Cells ; 42(10): 693-701, 2019 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-31617339

RESUMEN

Plants monitor changes in day length to coordinate their flowering time with appropriate seasons. In Arabidopsis , the diel and seasonal regulation of CONSTANS (CO) protein stability is crucial for the induction of FLOWERING LOCUS T (FT) gene in long days. FLAVIN-BINDING, KELCH REPEAT, F-BOX 1 (FKF1) and ZEITLUPE (ZTL) proteins control the shape of CO expression profile antagonistically, although regulation mechanisms remain unknown. In this study, we show that GIGANTEA (GI) protein modulates the stability and nuclear function of FKF1, which is closely related to the stabilization of CO in the afternoon of long days. The abundance of FKF1 protein is decreased by the gi mutation, but increased by GI overexpression throughout the day. Unlike the previous report, the translocation of FKF1 to the nucleus was not prevented by ZTL overexpression. In addition, the FKF1-ZTL complex formation is higher in the nucleus than in the cytosol. GI interacts with ZTL in the nucleus, implicating the attenuation of ZTL activity by the GI binding and, in turn, the sequestration of FKF1 from ZTL in the nucleus. We also found that the CO-ZTL complex presents in the nucleus, and CO protein abundance is largely reduced in the afternoon by ZTL overexpression, indicating that ZTL promotes CO degradation by capturing FKF1 in the nucleus under these conditions. Collectively, our findings suggest that GI plays a pivotal role in CO stability for the precise control of flowering by coordinating balanced functional properties of FKF1 and ZTL.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/genética , Núcleo Celular/metabolismo , Proteínas de Unión al ADN/metabolismo , Regulación de la Expresión Génica de las Plantas , Fotoperiodo , Unión Proteica , Estabilidad Proteica , Factores de Tiempo , Factores de Transcripción/metabolismo
14.
Postepy Biochem ; 65(3): 183-192, 2019 10 01.
Artículo en Polaco | MEDLINE | ID: mdl-31643165

RESUMEN

The canonical Wnt pathway is related to regulation of embryogenesis, cell differentiation and proliferation. Various proteins are necessary for proper signal transduction and ß-catenin serves as the main mediator. In off-state of the Wnt pathway ß-catenin undergoes proteasomal degradation, while in on-state increase of cytoplasmic concentration of ß-catenin occurs followed by ß-catenin translocation into the cell nucleus. Interaction between ß-catenin and TCF/LEF transcription factors activates the expression of over hundred target genes of the Wnt pathway. Highly active Wnt signaling is observed in many cancers, including head and neck squamous cell carcinomas. Knowledge of the functional structure of the canonical Wnt pathway enables search of therapeutic molecular targets to effectively inhibit transcriptional activity of ß-catenin in cancer cells.


Asunto(s)
Vía de Señalización Wnt , beta Catenina/metabolismo , Núcleo Celular/metabolismo , Citoplasma/metabolismo , Humanos , Neoplasias/metabolismo , Neoplasias/patología , Factores de Transcripción TCF/metabolismo , Vía de Señalización Wnt/genética
15.
Cell Biochem Biophys ; 77(4): 367-377, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31659617

RESUMEN

Cisplatin is a widely used anti-cancer drug. However, cisplatin is limited in clinical treatment because of its severe nephrotoxicity. This study reported whether O-GSP can antagonize the cisplatin-induced cytotoxicity in HEK293 cells through inducing HO-1 protein expression. We previously demonstrated O-GSP can increase the survival rate of HEK293 and have protective effect on HEK293 cells. Herein, We found that O-GSP can antagonize cisplatin nephrotoxicity through regulating the expression of HO-1. O-GSP promotes the translocation of Nrf2 in the nucleus, and activates the ERKN JNK pathway and p38 MAPK pathway. Interestingly, p38 MAPK plays a major role in HO-1 expression induced by O-GSP. And O-GSP can modulate the decrease of Nrf2 and HO-1 expression induced by cisplatin, and improve the cisplatin-induced activity and apoptosis rate of cells by stimulating the expression of HO-1. However, the protective effects of O-GSP are inhibited by ZnPP IX. Collectively, the results indicated that O-GSP induced the expression of HO-1 through p38MAPK and Nrf2 pathway in HEK293 cells.


Asunto(s)
Antineoplásicos/farmacología , Biflavonoides/farmacología , Catequina/farmacología , Cisplatino/farmacología , Hemo-Oxigenasa 1/metabolismo , Proantocianidinas/farmacología , Regulación hacia Arriba/efectos de los fármacos , Vitis/química , Apoptosis/efectos de los fármacos , Núcleo Celular/metabolismo , Células HEK293 , Humanos , Factor 2 Relacionado con NF-E2/metabolismo , Semillas/química , Semillas/metabolismo , Transducción de Señal/efectos de los fármacos , Vitis/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
16.
Nat Commun ; 10(1): 4764, 2019 10 18.
Artículo en Inglés | MEDLINE | ID: mdl-31628307

RESUMEN

Water is arguably the most common and yet least understood material on Earth. Indeed, the biophysical behavior of water in crowded intracellular milieu is a long-debated issue. Understanding of the spatial and compositional heterogeneity of water inside cells remains elusive, largely due to a lack of proper water-sensing tools with high sensitivity and spatial resolution. Recently, stimulated Raman excited fluorescence (SREF) microscopy was reported as the most sensitive vibrational imaging in the optical far field. Herein we develop SREF into a water-sensing tool by coupling it with vibrational solvatochromism. This technique allows us to directly visualize spatially-resolved distribution of water states inside single mammalian cells. Qualitatively, our result supports the concept of biological water and reveals intracellular water heterogeneity between nucleus and cytoplasm. Quantitatively, we unveil a compositional map of the water pool inside living cells. Hence we hope SREF will be a promising tool to study intracellular water and its relationship with cellular activities.


Asunto(s)
Microscopía Fluorescente/métodos , Microscopía Óptica no Lineal/métodos , Análisis de la Célula Individual/métodos , Agua/metabolismo , Núcleo Celular/química , Núcleo Celular/metabolismo , Fenómenos Fisiológicos Celulares , Color , Citoplasma/química , Citoplasma/metabolismo , Células HeLa , Humanos , Espacio Intracelular/química , Espacio Intracelular/metabolismo , Reproducibilidad de los Resultados , Solventes/química , Vibración , Agua/química
17.
Nat Cell Biol ; 21(10): 1248-1260, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31576060

RESUMEN

While nuclear lamina abnormalities are hallmarks of human diseases, their interplay with epigenetic regulators and precise epigenetic landscape remain poorly understood. Here, we show that loss of the lysine acetyltransferase MOF or its associated NSL-complex members KANSL2 or KANSL3 leads to a stochastic accumulation of nuclear abnormalities with genomic instability patterns including chromothripsis. SILAC-based MOF and KANSL2 acetylomes identified lamin A/C as an acetylation target of MOF. HDAC inhibition or acetylation-mimicking lamin A derivatives rescue nuclear abnormalities observed in MOF-deficient cells. Mechanistically, loss of lamin A/C acetylation resulted in its increased solubility, defective phosphorylation dynamics and impaired nuclear mechanostability. We found that nuclear abnormalities include EZH2-dependent histone H3 Lys 27 trimethylation and loss of nascent transcription. We term this altered epigenetic landscape "heterochromatin enrichment in nuclear abnormalities" (HENA). Collectively, the NSL-complex-dependent lamin A/C acetylation provides a mechanism that maintains nuclear architecture and genome integrity.


Asunto(s)
Núcleo Celular/ultraestructura , Histona Acetiltransferasas/metabolismo , Lamina Tipo A/metabolismo , Proteínas Nucleares/metabolismo , Acetilación , Animales , Núcleo Celular/metabolismo , Células Cultivadas , Epigénesis Genética , Fibroblastos , Heterocromatina , Histona Acetiltransferasas/genética , Histonas/genética , Histonas/metabolismo , Lamina Tipo A/química , Lamina Tipo A/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Proteínas Nucleares/genética
18.
Int J Nanomedicine ; 14: 7173-7190, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31564872

RESUMEN

Background: Nanotechnology proposes the use of gold nanoparticles (AuNPs) for drug delivery, diagnosis, and treatment of cancer. Leukemia is a type of hematopoietic cancer that results from the malignant transformation of white blood cells. Chitosan-coated AuNPs (CH-AuNPs) are cell death inductors in HeLa and MCF-7 cancer cells without affecting peripheral blood mononuclear cells (PBMC). Considering the selectivity and versatile cytotoxicity of CH-AuNPs, we evaluated whether their selectivity is due to the cell lineage or the characteristics of the cancer cells, by assessing its cytotoxicity in leukemic cells. Moreover, we further examined the cell death mechanism and assessed the implication of nuclear damage, autophagosome formation, and the cell death mechanism induced in leukemic cells. Materials and methods: We synthesized CH-AuNPs by chemical methods and analyzed their cell death capacity in a T-acute lymphocytic leukemia cell line (CEM), in a chronic myeloid leukemia cell line (K562), and in healthy cells from the same lineage (PBMC and bone marrow, BM, cells). Then, we assessed ROS generation and mitochondrial and nuclear damage. Finally, we evaluated whether cell death occurred by autophagy, apoptosis, or necroptosis, and the role of ROS in this mechanism. Results: We found that CH-AuNPs did not affect PBMC and BM cells, whereas they are cytotoxic in a dose-dependent manner in leukemic cells. ROS production leads to mitochondrial and nuclear damage, and cell death. We found that CH-AuNPs induce apoptosis in CEM and necroptosis in K562, both undergoing autophagy as a pro-survival mechanism. Conclusion: CH-AuNPs are selective cell death inductors in hematologic cancer cells, without affecting their healthy counterparts. Cell death induced by CH-AuNPs is independent of the cancer cell type; however, its mechanism is different depending on the type of leukemic cells.


Asunto(s)
Apoptosis , Quitosano/química , Oro/química , Leucemia/patología , Nanopartículas del Metal/química , Especies Reactivas de Oxígeno/metabolismo , Animales , Autofagosomas/metabolismo , Autofagia , Caspasa 3/metabolismo , Línea Celular Tumoral , Permeabilidad de la Membrana Celular , Núcleo Celular/metabolismo , Supervivencia Celular , Activación Enzimática , Humanos , Leucemia/enzimología , Leucocitos Mononucleares/metabolismo , Masculino , Ratones , Mitocondrias/metabolismo , Necrosis , Fosfatidilserinas/metabolismo
19.
Int J Nanomedicine ; 14: 8195-8208, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31632027

RESUMEN

Background: Zinc oxide nanoparticles (ZnO NPs) are used in modern cancer therapy based on their specific target, efficacy, low toxicity and biocompatibility. The photocatalytic performance of Zinc oxide (ZnO) nanocomposites with hyaluronic acid (HA) was used to study anticancer properties against various human cancer cell lines. Methods: Zinc oxide (ZnO) nanocomposites functionalized by hyaluronic acid (HA) were prepared by a co-precipitation method (HA-ZnONcs). The submicron-flower-shaped nanocomposites were further functionalized with ginsenoside Rh2 by a cleavable ester bond via carbodiimide chemistry to form Rh2HAZnO. The physicochemical behaviors of the synthesized ZnO nanocomposites were characterized by various analytical and spectroscopic techniques. We carried out 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay to evaluate the toxicity of Rh2HAZnO in various human cancer cells (A549, MCF-7, and HT29). Furthermore, to confirm the apoptotic effects of Rh2HAZnO and to determine the role of the Caspase-9/p38 MAPK pathways by various molecular techniques such as RT-PCR and Western blotting. Furthermore, Rh2HAZnO induced morphological changes of these cell lines, mainly intracellular reactive oxygen species (ROS) were observed by ROS staining and nucleus by Hoechst staining. Results: We confirmed that Rh2HAZnO exhibits the anti-cancer effects on A549 lung cancer, HT29 colon cancer, and MCF7 breast cancer cells. Moreover, intracellular reactive oxygen species (ROS) were observed in three cancer cell lines. Rh2HAZnO induced apoptotic process through p53-mediated pathway by upregulating p53 and BAX and downregulating BCL2. Specifically, Rh2HAZnO induced activation of cleaved PARP (Asp214) in A549 lung cancer cells and upregulated Caspase-9/phosphorylation of p38 MAPK in other cell lines (HT29 and MCF-7). Furthermore, Rh2HAZnO induced morphological changes in the nucleus of these cell lines. Conclusion: These results suggest that the potential anticancer activity of novel Rh2HAZnO nanoparticles might be linked to induction of apoptosis through the generation of ROS by activation of the Caspase-9/p38 MAPK pathway.


Asunto(s)
Apoptosis/efectos de los fármacos , Caspasa 9/metabolismo , Ginsenósidos/farmacología , Ácido Hialurónico/farmacología , Luminiscencia , Nanopartículas/química , Óxido de Zinc/farmacología , Células A549 , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Supervivencia Celular/efectos de los fármacos , Daño del ADN , Humanos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Nanopartículas/ultraestructura , Especies Reactivas de Oxígeno/metabolismo , Óxido de Zinc/química , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo
20.
PLoS Pathog ; 15(9): e1007921, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31568537

RESUMEN

Humans are frequently exposed to bacterial genotoxins involved in digestive cancers, colibactin and Cytolethal Distending Toxin (CDT), the latter being secreted by many pathogenic bacteria. Our aim was to evaluate the effects induced by these genotoxins on nuclear remodeling in the context of cell survival. Helicobacter infected mice, coculture experiments with CDT- and colibactin-secreting bacteria and hepatic, intestinal and gastric cells, and xenograft mouse-derived models were used to assess the nuclear remodeling in vitro and in vivo. Our results showed that CDT and colibactin induced-nuclear remodeling can be associated with the formation of deep cytoplasmic invaginations in the nucleus of giant cells. These structures, observed both in vivo and in vitro, correspond to nucleoplasmic reticulum (NR). The core of the NR was found to concentrate ribosomes, proteins involved in mRNA translation, polyadenylated RNA and the main components of the complex mCRD involved in mRNA turnover. These structures are active sites of mRNA translation, correlated with a high degree of ploidy, and involve MAPK and calcium signaling. Additional data showed that insulation and concentration of these adaptive ribonucleoprotein particles within the nucleus are dynamic, transient and protect the cell until the genotoxic stress is relieved. Bacterial genotoxins-induced NR would be a privileged gateway for selected mRNA to be preferably transported therein for local translation. These findings offer new insights into the context of NR formation, a common feature of many cancers, which not only appears in response to therapies-induced DNA damage but also earlier in response to genotoxic bacteria.


Asunto(s)
Toxinas Bacterianas/toxicidad , Helicobacter/patogenicidad , Ribonucleoproteínas/metabolismo , Animales , Línea Celular , Núcleo Celular/efectos de los fármacos , Núcleo Celular/metabolismo , Núcleo Celular/patología , Supervivencia Celular , Daño del ADN , Infecciones por Helicobacter/metabolismo , Infecciones por Helicobacter/patología , Hepatocitos/metabolismo , Hepatocitos/patología , Humanos , Ratones , Ratones Endogámicos C57BL , Microscopía Electrónica de Transmisión , Mutágenos/toxicidad , Péptidos/toxicidad , Policétidos/toxicidad , ARN Mensajero/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA