Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
1.
Cancers (Basel) ; 14(4)2022 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-35205817

RESUMEN

Surgical resection is the mainstay in intended curative treatment of colorectal cancer (CRC) and may be accompanied by adjuvant chemotherapy. However, 40% of the patients experience recurrence within five years of treatment, highlighting the importance of improved, personalized treatment options. Monolayer cell cultures and murine models, which are generally used to study the biology of CRC, are associated with certain drawbacks; hence, the use of organoids has been emerging. Organoids obtained from tumors display similar genotypic and phenotypic characteristics, making them ideal for investigating individualized treatment strategies and for integration as a core platform to be used in prediction models. Here, we review studies correlating the clinical response in patients with CRC with the therapeutic response in patient-derived organoids (PDO), as well as the limitations and potentials of this model. The studies outlined in this review reported strong associations between treatment responses in the PDO model and clinical treatment responses. However, as PDOs lack the tumor microenvironment, they do not genuinely account for certain crucial characteristics that influence therapeutic response. To this end, we reviewed studies investigating PDOs co-cultured with tumor-infiltrating lymphocytes. This model is a promising method allowing evaluation of patient-specific tumors and selection of personalized therapies. Standardized methodologies must be implemented to reach a "gold standard" for validating the use of this model in larger cohorts of patients. The introduction of this approach to a clinical scenario directing neoadjuvant treatment and in other curative and palliative treatment strategies holds incredible potential for improving personalized treatment and its outcomes.

2.
FEBS Open Bio ; 11(6): 1638-1644, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33838073

RESUMEN

Dysregulation of interleukin-33 (IL-33) has been implicated in the pathogenesis of several autoimmune and inflammatory diseases, but few studies have examined transcriptional regulation of the IL33 gene. In the intestines, gene regulation is controlled by a transcription factor network of which the intestinal-specific transcription factor CDX2 is a key component. In this study, we investigated whether CDX2 regulates IL33 mRNA expression. We examined IL33 mRNA expression in primary colonic epithelial cells from healthy humans and epithelial cell lines, revealing high expression levels in primary colonic and LS174T cells. Combining genomics data (ChIP-seq, RNA-seq) and IL33 promoter analyses in LS174T cells revealed intronic enhancer activity in the IL33 gene that is dependent on CDX2 expression. Western blotting and qRT-PCR confirmed that IL33 expression is upregulated in a CDX2 concentration-dependent manner, thereby providing the first evidence that CDX2 regulates the expression of IL33.


Asunto(s)
Factor de Transcripción CDX2/metabolismo , Células Epiteliales/metabolismo , Interleucina-33/genética , Intestinos/metabolismo , Factor de Transcripción CDX2/genética , Humanos , Interleucina-33/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Células Tumorales Cultivadas
3.
Sci Rep ; 8(1): 11813, 2018 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-30087389

RESUMEN

The type II membrane-anchored serine protease, matriptase, encoded by suppression of tumorgenicity-14 (ST14) regulates the integrity of the intestinal epithelial barrier in concert with its inhibitor, HAI-1 encoded by serine peptidase inhibitor, Kunitz type -1 (SPINT1). The balance of the protease/inhibitor gene expression ratio is vital in preventing the oncogenic potential of matriptase. The intestinal cell lineage is regulated by a transcriptional regulatory network where the tumor suppressor, Caudal homeobox 2 (CDX2) is considered to be an intestinal master transcription factor. In this study, we show that CDX2 has a dual function in regulating both ST14 and SPINT1, gene expression in intestinal cells. We find that CDX2 is not required for the basal ST14 and SPINT1 gene expression; however changes in CDX2 expression affects the ST14/SPINT1 mRNA ratio. Exploring CDX2 ChIP-seq data from intestinal cell lines, we identified genomic CDX2-enriched enhancer elements for both ST14 and SPINT1, which regulate their corresponding gene promoter activity. We show that CDX2 displays both repressive and enhancing regulatory abilities in a cell specific manner. Together, these data reveal new insight into transcriptional mechanisms controlling the intestinal matriptase/inhibitor balance.


Asunto(s)
Factor de Transcripción CDX2/metabolismo , Proteínas de Ciclo Celular/biosíntesis , Elementos de Facilitación Genéticos , Regulación de la Expresión Génica , Mucosa Intestinal/metabolismo , Proteínas Asociadas a Microtúbulos/biosíntesis , Fosfoproteínas/biosíntesis , Serina Endopeptidasas/biosíntesis , Factor de Transcripción CDX2/genética , Células CACO-2 , Proteínas de Ciclo Celular/genética , Células HeLa , Humanos , Mucosa Intestinal/citología , Proteínas Asociadas a Microtúbulos/genética , Fosfoproteínas/genética , Serina Endopeptidasas/genética
4.
PLoS One ; 13(7): e0200215, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29975781

RESUMEN

Sequencing of primary colorectal tumors has identified a gene fusion in approximately 3% of colorectal cancer patients of the VTI1A and TCF7L2 genes, encoding a VTI1A-TCF4 fusion protein containing a truncated TCF4. As dysregulation of the Wnt signaling pathway is associated with colorectal cancer development and progression, the functional properties and transcriptional regulation of the VTI1A-TCF4 fusion protein may also play a role in these processes. Functional characteristics of the VTI1A-TCF4 fusion protein in Wnt signaling were analyzed in NCI-H508 and LS174T colon cancer cell lines. The NCI-H508 cell line, containing the VTI1A-TCF7L2 fusion gene, showed no active Wnt signaling, and overexpression of the VTI1A-TCF4 fusion protein in LS174T cells along with a Wnt signaling luciferase reporter plasmid showed inhibition of activity. The transcriptional regulation of the VTI1A-TCF4 fusion gene was investigated in LS174T cells where the activity of the VTI1A promoter was compared to that of the TCF7L2 promoter, and the transcription factor CDX2 was analyzed for gene regulatory activity of the VTI1A promoter through luciferase reporter gene assay using colon cancer cell lines as a model. Transfection of LS174T cells showed that the VTI1A promoter is highly active compared to the TCF7L2 promoter, and that CDX2 activates transcription of VTI1A. These results suggest that the VTI1A-TCF4 fusion protein is a dominant negative regulator of the Wnt signaling pathway, and that transcription of VTI1A is activated by CDX2.


Asunto(s)
Factor de Transcripción CDX2/genética , Neoplasias del Colon/genética , Proteínas de Fusión Oncogénica/genética , Proteínas Qb-SNARE/genética , Proteína 2 Similar al Factor de Transcripción 7/genética , Vía de Señalización Wnt , Sitios de Unión , Factor de Transcripción CDX2/metabolismo , Línea Celular Tumoral , Neoplasias del Colon/metabolismo , Neoplasias del Colon/patología , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Genes Reporteros , Humanos , Intestinos/patología , Proteínas de Fusión Oncogénica/metabolismo , Regiones Promotoras Genéticas , Proteínas Qb-SNARE/metabolismo , Proteína 2 Similar al Factor de Transcripción 7/metabolismo , beta Catenina/metabolismo
5.
Nat Commun ; 9(1): 1661, 2018 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-29695774

RESUMEN

Inflammatory bowel disease (IBD) is a chronic intestinal disorder, with two main types: Crohn's disease (CD) and ulcerative colitis (UC), whose molecular pathology is not well understood. The majority of IBD-associated SNPs are located in non-coding regions and are hard to characterize since regulatory regions in IBD are not known. Here we profile transcription start sites (TSSs) and enhancers in the descending colon of 94 IBD patients and controls. IBD-upregulated promoters and enhancers are highly enriched for IBD-associated SNPs and are bound by the same transcription factors. IBD-specific TSSs are associated to genes with roles in both inflammatory cascades and gut epithelia while TSSs distinguishing UC and CD are associated to gut epithelia functions. We find that as few as 35 TSSs can distinguish active CD, UC, and controls with 85% accuracy in an independent cohort. Our data constitute a foundation for understanding the molecular pathology, gene regulation, and genetics of IBD.


Asunto(s)
Colitis Ulcerosa/genética , Enfermedad de Crohn/genética , Secuencias Reguladoras de Ácidos Nucleicos/genética , Adulto , Biopsia , Estudios de Casos y Controles , Estudios de Cohortes , Colitis Ulcerosa/diagnóstico , Colitis Ulcerosa/patología , Colon/diagnóstico por imagen , Colon/patología , Colonoscopía , Enfermedad de Crohn/diagnóstico , Enfermedad de Crohn/patología , Femenino , Humanos , Mucosa Intestinal/diagnóstico por imagen , Mucosa Intestinal/patología , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ARN , Regulación hacia Arriba
6.
Methods Mol Biol ; 1765: 57-77, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29589301

RESUMEN

Several tumor suppressors possess gene regulatory activity. Here, we describe how promoter and promoter/enhancer reporter assays can be used to characterize a colorectal tumor suppressor proteins' gene regulatory activity of possible target genes. In the first part, a bioinformatic approach to identify relevant gene regulatory regions of potential target genes is presented. In the second part, it is demonstrated how to prepare and carry out the functional assay.We explain how to clone the bioinformatically identified gene regulatory regions into luciferase reporter plasmids by the use of the quick and efficient In-Fusion cloning method, and how to carry out transient transfections of Caco-2 colon cancer cells with the produced luciferase reporter plasmids using polyethyleneimine (PEI). A plan describing how to set up and carry out the luciferase expression assay is presented. The luciferase/ß-galactosidase (Dual Light) assay presented is a highly sensitive assay that can monitor small changes in the promoter/enhancer activity and includes an internal control monitoring transfection efficiency.


Asunto(s)
Bioensayo/métodos , Neoplasias Colorrectales/genética , Regulación Neoplásica de la Expresión Génica , Regiones Promotoras Genéticas/genética , Proteínas Supresoras de Tumor/metabolismo , Bioensayo/instrumentación , Factor de Transcripción CDX2/metabolismo , Células CACO-2 , Clonación Molecular/métodos , Biología Computacional/métodos , Genes Reporteros/genética , Humanos , Luciferasas/química , Luciferasas/genética , Glicoproteínas de Membrana/genética , Transcripción Genética , Proteínas Supresoras de Tumor/genética
7.
Nucleic Acids Res ; 45(13): e123, 2017 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-28472465

RESUMEN

Tetracycline-based inducible systems provide powerful methods for functional studies where gene expression can be controlled. However, the lack of tight control of the inducible system, leading to leakiness and adverse effects caused by undesirable tetracycline dosage requirements, has proven to be a limitation. Here, we report that the combined use of genome editing tools and last generation Tet-On systems can resolve these issues. Our principle is based on precise integration of inducible transcriptional elements (coined PrIITE) targeted to: (i) exons of an endogenous gene of interest (GOI) and (ii) a safe harbor locus. Using PrIITE cells harboring a GFP reporter or CDX2 transcription factor, we demonstrate discrete inducibility of gene expression with complete abrogation of leakiness. CDX2 PrIITE cells generated by this approach uncovered novel CDX2 downstream effector genes. Our results provide a strategy for characterization of dose-dependent effector functions of essential genes that require absence of endogenous gene expression.


Asunto(s)
Edición Génica/métodos , Regulación de la Expresión Génica , Factor de Transcripción CDX2/antagonistas & inhibidores , Factor de Transcripción CDX2/genética , Línea Celular , Exones , Perfilación de la Expresión Génica , Técnicas de Inactivación de Genes , Marcación de Gen , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Humanos , Tetraciclina
8.
J Cell Biochem ; 118(2): 298-307, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27333824

RESUMEN

The expression of Caudal-related homeobox transcription factor 2 (CDX2) is impaired by tumor necrosis factor-α (TNF-α)-mediated activation of nuclear factor-κB (NF-κB) in ulcerative colitis (UC). Laminin subunit γ2 (LAMC2) is an epithelial basement membrane protein implicated in cell migration, proliferation, differentiation, as well as tumor invasion and intestinal inflammation, and its expression is enhanced by TNF-α in a NF-κB-dependent regulation of the recently identified LAMC2 enhancer. The aim was to determine whether CDX2 is involved in the basal regulation of LAMC2 in epithelial cells and to assess the influence of inflammation. Transcriptional regulation of LAMC2 was examined by reporter gene assays, overexpression, and shRNA-mediated knock-down of CDX2. CDX2-DNA interactions were assessed by chromatin immunoprecipitation on Caco-2 cells without or with TNF-α, as well as in purified colonic human epithelial cells. Immunohistochemical staining and quantitative reverse-transcription polymerase chain reaction analyses were used to measure the expression of CDX2 and LAMC2 in colonic biopsies from healthy controls and patients with UC. These data indicate that CDX2 directly regulates LAMC2 gene expression through interaction with elements in the LAMC2 promoter region. We further revealed an inverse effect of inflammation on CDX2 and LAMC2. The data presented provide a novel insight into how CDX2 is implicated in the transcriptional regulation of LAMC2 in intestinal epithelial cells, a function that is impaired during mucosal inflammation where a high level of TNF-α is present. J. Cell. Biochem. 118: 298-307, 2017. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Factor de Transcripción CDX2/biosíntesis , Colitis/metabolismo , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Mucosa Intestinal/metabolismo , Laminina/metabolismo , Células CACO-2 , Colitis/patología , Colon , Células Epiteliales/patología , Femenino , Humanos , Inflamación/metabolismo , Inflamación/patología , Mucosa Intestinal/patología , Masculino , Factor de Necrosis Tumoral alfa/metabolismo
9.
J Med Genet ; 54(3): 166-175, 2017 03.
Artículo en Inglés | MEDLINE | ID: mdl-27627987

RESUMEN

BACKGROUND: Levels of serum thyroid-stimulating hormone (TSH) indicate thyroid function, because thyroid hormone negatively controls TSH release. Genetic variants in the vascular endothelial growth factor A (VEGFA) gene are associated with TSH levels. The aim of this study was to characterise the association of VEGFA variants with TSH in a Danish cohort and to identify and characterise functional variants. METHODS: We performed an association study of the VEGFA locus for circulating TSH levels in 8445 Danish individuals. Lead variants were tested for allele-specific effects in vitro using luciferase reporter and gel-shift assays. RESULTS: Four SNPs in VEGFA were associated with circulating TSH (rs9472138, rs881858, rs943080 and rs4711751). For rs881858, the presence of each G-allele was associated with a corresponding decrease in TSH levels of 2.3% (p=8.4×10-9) and an increase in circulating free T4 levels (p=0.0014). The SNP rs881858 is located in a binding site for CHOP (C/EBP homology protein) and c/EBPß (ccaat enhancer binding protein ß). Reporter-gene analysis showed increased basal enhancer activity of the rs881858 A-allele versus the G-allele (34.5±9.9% (average±SEM), p=0.0012), while co-expression of CHOP effectively suppressed the rs881858 A-allele activity. The A-allele showed stronger binding to CHOP in gel-shift assays. CONCLUSIONS: VEGF is an important angiogenic signal required for tissue expansion. We show that VEGFA variation giving allele-specific response to transcription factors with overlapping binding sites associate closely with circulating TSH levels. Because CHOP is induced by several types of intracellular stress, this indicates that cellular stress could be involved in the normal or pathophysiological response of the thyroid to TSH. TRIAL REGISTRATION NUMBER: NCT00289237, NCT00316667; Results.


Asunto(s)
Isquemia Miocárdica/genética , Tirotropina/sangre , Factor de Transcripción CHOP/genética , Factor A de Crecimiento Endotelial Vascular/genética , Dinamarca , Elementos de Facilitación Genéticos , Femenino , Estudios de Asociación Genética , Predisposición Genética a la Enfermedad , Heterocigoto , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/sangre , Isquemia Miocárdica/patología , Polimorfismo de Nucleótido Simple , Unión Proteica/genética , Glándula Tiroides/metabolismo , Glándula Tiroides/patología , Tirotropina/deficiencia , Tirotropina/genética
10.
Am J Physiol Gastrointest Liver Physiol ; 308(2): G92-9, 2015 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-25394657

RESUMEN

Identification of pathways involved in wound healing is important for understanding the pathogenesis of various intestinal diseases. Cellular inhibitor of apoptosis protein 2 (cIAP2) regulates proliferation and migration in nonepithelial cells and is expressed in human colonocytes. The aim of the study was to investigate the role of cIAP2 for wound healing in the normal human colon. Wound tissue was generated by taking rectosigmoidal biopsies across an experimental ulcer in healthy subjects after 5, 24, and 48 h. In experimental ulcers, the expression of cIAP2 in regenerating intestinal epithelial cells (IECs) was increased at the wound edge after 24 h (P < 0.05), returned to normal after reepithelialization, and correlated with the inflammatory reaction in the experimental wounds (P < 0.001). cIAP2 was induced in vitro in regenerating Caco2 IECs after wound infliction (P < 0.01). Knockdown of cIAP2 caused a substantial impairment of the IEC regeneration through inhibition of migration (P < 0.005). cIAP2 overexpression lead to formation of migrating IECs and upregulation of expression of RhoA and Rac1 as well as GTP-activation of Rac1. Transforming growth factor-ß1 enhanced the expression of cIAP2 but was not upregulated in wounds in vivo and in vitro. NF-κB and MAPK pathways did not affect cIAP2 expression. cIAP2 is in conclusion a regulator of human intestinal wound healing through enhanced migration along with activation of Rac1, and the findings suggest that cIAP2 could be a future therapeutic target to improve intestinal wound healing.


Asunto(s)
Apoptosis/fisiología , Movimiento Celular/fisiología , Proteínas Inhibidoras de la Apoptosis/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Proteína 3 que Contiene Repeticiones IAP de Baculovirus , Línea Celular , Colon/metabolismo , Activación Enzimática , Células Epiteliales/metabolismo , Humanos , Mucosa Intestinal/metabolismo , FN-kappa B/metabolismo , Factor de Crecimiento Transformador beta1/metabolismo , Ubiquitina-Proteína Ligasas , Cicatrización de Heridas/fisiología
11.
DNA Res ; 21(6): 569-83, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24990076

RESUMEN

The Caco-2 cell line is one of the most important in vitro models for enterocytes, and is used to study drug absorption and disease, including inflammatory bowel disease and cancer. In order to use the model optimally, it is necessary to map its functional entities. In this study, we have generated genome-wide maps of active transcription start sites (TSSs), and active enhancers in Caco-2 cells with or without tumour necrosis factor (TNF)-α stimulation to mimic an inflammatory state. We found 520 promoters that significantly changed their usage level upon TNF-α stimulation; of these, 52% are not annotated. A subset of these has the potential to confer change in protein function due to protein domain exclusion. Moreover, we locate 890 transcribed enhancer candidates, where ∼50% are changing in usage after TNF-α stimulation. These enhancers share motif enrichments with similarly responding gene promoters. As a case example, we characterize an enhancer regulating the laminin-5 γ2-chain (LAMC2) gene by nuclear factor (NF)-κB binding. This report is the first to present comprehensive TSS and enhancer maps over Caco-2 cells, and highlights many novel inflammation-specific promoters and enhancers.


Asunto(s)
Mapeo Cromosómico , Elementos de Respuesta/fisiología , Iniciación de la Transcripción Genética/efectos de los fármacos , Iniciación de la Transcripción Genética/fisiología , Factor de Necrosis Tumoral alfa/metabolismo , Células CACO-2 , Estudio de Asociación del Genoma Completo , Humanos , Laminina/biosíntesis , Laminina/genética , FN-kappa B/genética , FN-kappa B/metabolismo , Factor de Necrosis Tumoral alfa/farmacología
12.
Carcinogenesis ; 35(5): 1185-92, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24501326

RESUMEN

Tumor necrosis factor-α (TNF-α) is highly upregulated in inflammation and reduces the expression of the intestinal transcription factor, Caudal-related homeobox transcription factor 2 (CDX2). Wnt/ß-catenin signaling is critical for intestinal cell proliferation, but a decreased CDX2 expression has influence on the Wnt signaling-related genes and progression of colorectal cancer. Although several inflammatory signaling pathways, including TNF-α, have been reported to promote Wnt/ß-catenin activity and development of cancer, the underlying molecular mechanisms remain unclear. The aim was to investigate the signaling pathways involved in the TNF-α-mediated downregulation of CDX2, and its influence on Wnt/ß-catenin signaling components in colon cancer cells. The expression of TNF-α and CDX2 at the invasive front were evaluated by immunohistochemical staining and showed reduced CDX2-positive cells in tumor buddings in areas with TNF-α expression in the surrounding inflammatory cells. In vitro studies revealed that TNF-α treatment showed a dose-dependent decrease of CDX2 messenger RNA (mRNA) and protein expression in Caco-2 cells. Inhibition of nuclear factor-kappaB or p38 pathways showed that these are involved in the TNF-α-dependent downregulation of CDX2. Furthermore, TNF-α-mediated downregulation of CDX2 was found to significantly decrease the mRNA levels of adenomatous polyposis coli (APC), axis inhibition protein 2 (AXIN2) and glycogen synthase kinase-3 beta (GSK3ß), whereas the mRNA levels of Wnt targets were significantly elevated in TNF-α-treated Caco-2 cells. These findings were associated with reduced binding of CDX2 to promoter or enhancer regions of APC, AXIN2 and GSK3ß. In conclusion, it was found that TNF-α induces the expression of Wnt signaling components through a downregulation of the CDX2 expression that might have a tumor-promoting effect on colon cancer cells.


Asunto(s)
Neoplasias del Colon/metabolismo , Proteínas de Homeodominio/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Vía de Señalización Wnt , Factor de Transcripción CDX2 , Células CACO-2 , Neoplasias del Colon/genética , Expresión Génica , Regulación Neoplásica de la Expresión Génica , Proteínas de Homeodominio/genética , Humanos , Inmunohistoquímica , Sistema de Señalización de MAP Quinasas , FN-kappa B/metabolismo , Unión Proteica , beta Catenina/genética , beta Catenina/metabolismo
13.
World J Gastroenterol ; 19(27): 4289-99, 2013 Jul 21.
Artículo en Inglés | MEDLINE | ID: mdl-23885139

RESUMEN

AIM: To use microarray-based miRNA profiling of colonic mucosal biopsies from patients with ulcerative colitis (UC), Crohn's disease (CD), and controls in order to identify new potential miRNA biomarkers in inflammatory bowel disease. METHODS: Colonic mucosal pinch biopsies from the descending part were obtained endoscopically from patients with active UC or CD, quiescent UC or CD, as well as healthy controls. Total RNA was isolated and miRNA expression assessed using the miRNA microarray Geniom Biochip miRNA Homo sapiens (Febit GmbH, Heidelberg, Germany). Data analysis was carried out by principal component analysis and projection to latent structure-discriminant analysis using the SIMCA-P+12 software package (Umetrics, Umea, Sweden). The microarray data were subsequently validated by quantitative real-time polymerase chain reaction (qPCR) performed on colonic tissue samples from active UC patients (n = 20), patients with quiescent UC (n = 19), and healthy controls (n = 20). The qPCR results were analyzed with Mann-Whitney U test. In silico prediction analysis were performed to identify potential miRNA target genes and the predicted miRNA targets were then compared with all UC associated susceptibility genes reported in the literature. RESULTS: The colonic mucosal miRNA transcriptome differs significantly between UC and controls, UC and CD, as well as between UC patients with mucosal inflammation and those without. However, no clear differences in the transcriptome of patients with CD and controls were found. The miRNAs with the strongest differential power were identified (miR-20b, miR-99a, miR-203, miR-26b, and miR-98) and found to be up-regulated more than a 10-fold in active UC as compared to quiescent UC, CD, and controls. Two miRNAs, miR-125b-1* and let-7e*, were up-regulated more than 5-fold in quiescent UC compared to active UC, CD, and controls. Four of the seven miRNAs (miR-20b, miR-98, miR-125b-1*, and let-7e*) were validated by qPCR and found to be specifically upregulated in patients with UC. Using in silico analysis we found several predicted pro-inflammatory target genes involved in various pathways, such as mitogen-activated protein kinase and cytokine signaling, which are both key signaling pathways in UC. CONCLUSION: The present study provides the first evidence that miR-20b, miR-98, miR-125b-1*, and let-7e* are deregulated in patients with UC. The level of these miRNAs may serve as new potential biomarkers for this chronic disease.


Asunto(s)
Colitis Ulcerosa/diagnóstico , Enfermedad de Crohn/diagnóstico , MicroARNs/metabolismo , Adulto , Anciano , Biomarcadores/metabolismo , Biopsia , Estudios de Casos y Controles , Colitis Ulcerosa/metabolismo , Enfermedad de Crohn/metabolismo , Femenino , Regulación de la Expresión Génica , Humanos , Sistema de Señalización de MAP Quinasas , Masculino , Persona de Mediana Edad , Análisis de Secuencia por Matrices de Oligonucleótidos , Reacción en Cadena de la Polimerasa , Programas Informáticos
14.
Carcinogenesis ; 34(6): 1361-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23393221

RESUMEN

Wnt signaling is often constitutively active in colorectal cancer cells. The expression of the intestinal specific transcription factor CDX2 is found to be transiently decreased in invasive cells at the tumor/stroma interface. A recent ChIP-Seq study has indicated that several Wnt signaling-related genes are regulated by CDX2. The aim was to investigate the role of decreased CDX2 level on the expression of APC, AXIN2 and GSK3ß in migrating colon cancer cells at the invasive front. CDX2-bound promoter and enhancer regions from APC, AXIN2 and GSK3ß were analyzed for gene regulatory activity and the expression pattern of APC and GSK3ß at the invasive front was evaluated by immunohistochemical procedures. Transfection of intestinal and non-intestinal cell lines demonstrated that CDX2 activated APC and AXIN2 promoter activities via intestinal cell-specific enhancer elements. Suppressed CDX2 expression was associated with endogenous downregulation of APC and AXIN2 expression in Caco-2 cells but did not affect GSK3ß expression. Furthermore, elevated levels of nuclear ß-catenin and reduced levels of cytoplasmic APC were correlated to a low CDX2 expression in migrating colon cancer cells in vivo. These results suggest that a low CDX2 level has influence on the Wnt signaling in invasive colon cancer cells possibly promoting cellular migration.


Asunto(s)
Proteína de la Poliposis Adenomatosa del Colon/biosíntesis , Proteína Axina/biosíntesis , Neoplasias Colorrectales/metabolismo , Glucógeno Sintasa Quinasa 3/biosíntesis , Proteínas de Homeodominio/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Factor de Transcripción CDX2 , Células CACO-2 , Línea Celular Tumoral , Movimiento Celular , Neoplasias Colorrectales/genética , Femenino , Regulación Neoplásica de la Expresión Génica , Glucógeno Sintasa Quinasa 3 beta , Células HeLa , Humanos , Masculino , Persona de Mediana Edad , Regiones Promotoras Genéticas , Unión Proteica , Transducción de Señal , Vía de Señalización Wnt , beta Catenina/biosíntesis
15.
PLoS One ; 7(2): e32394, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22384239

RESUMEN

Analyzing data obtained from genome-wide gene expression experiments is challenging due to the quantity of variables, the need for multivariate analyses, and the demands of managing large amounts of data. Here we present the R package pcaGoPromoter, which facilitates the interpretation of genome-wide expression data and overcomes the aforementioned problems. In the first step, principal component analysis (PCA) is applied to survey any differences between experiments and possible groupings. The next step is the interpretation of the principal components with respect to both biological function and regulation by predicted transcription factor binding sites. The robustness of the results is evaluated using cross-validation, and illustrative plots of PCA scores and gene ontology terms are available. pcaGoPromoter works with any platform that uses gene symbols or Entrez IDs as probe identifiers. In addition, support for several popular Affymetrix GeneChip platforms is provided. To illustrate the features of the pcaGoPromoter package a serum stimulation experiment was performed and the genome-wide gene expression in the resulting samples was profiled using the Affymetrix Human Genome U133 Plus 2.0 chip. Array data were analyzed using pcaGoPromoter package tools, resulting in a clear separation of the experiments into three groups: controls, serum only and serum with inhibitor. Functional annotation of the axes in the PCA score plot showed the expected serum-promoted biological processes, e.g., cell cycle progression and the predicted involvement of expected transcription factors, including E2F. In addition, unexpected results, e.g., cholesterol synthesis in serum-depleted cells and NF-κB activation in inhibitor treated cells, were noted. In summary, the pcaGoPromoter R package provides a collection of tools for analyzing gene expression data. These tools give an overview of the input data via PCA, functional interpretation by gene ontology terms (biological processes), and an indication of the involvement of possible transcription factors.


Asunto(s)
Biología Computacional/métodos , Perfilación de la Expresión Génica , Análisis de Componente Principal , Algoritmos , Animales , Sitios de Unión , Interpretación Estadística de Datos , Humanos , Internet , Ratones , Modelos Estadísticos , Monocitos/citología , Análisis de Secuencia por Matrices de Oligonucleótidos , Lenguajes de Programación , Regiones Promotoras Genéticas , Ratas , Procesamiento de Señales Asistido por Computador
16.
Biochim Biophys Acta ; 1822(6): 843-51, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22326557

RESUMEN

BACKGROUND/AIMS: High levels of pro-inflammatory cytokines are linked to inflammatory bowel disease (IBD). The transcription factor Caudal-related homeobox transcription factor 2 (CDX2) plays a crucial role in differentiation of intestinal epithelium and regulates IBD-susceptibility genes, including meprin 1A (MEP1A). The aim was to investigate the expression of CDX2 and MEP1A in colitis; to assess if they are regulated by tumor necrosis factor-α (TNF-α), and finally to reveal if CDX2 is involved in a TNF-α-induced down-regulation of MEP1A. METHODS: Expression of CDX2 and MEP1A was investigated in colonic biopsies of ulcerative colitis (UC) patients and in dextran sodium sulfate (DSS)-induced colitis. CDX2 protein expression was investigated by immunoblotting and immunohistochemical procedures. CDX2 and MEP1A regulation was examined in TNF-α-treated Caco-2 cells by reverse transcription-polymerase chain reaction and with reporter gene assays, and the effect of anti-TNF-α treatment was assessed using infliximab. Finally, in vivo CDX2-DNA interactions were investigated by chromatin immunoprecipitation. RESULTS: The CDX2 and MEP1A mRNA expression was significantly decreased in active UC patients and in DSS-colitis. Colonic biopsy specimens from active UC showed markedly decreased CDX2 staining. TNF-α treatment diminished the CDX2 and MEP1A mRNA levels, a decrease which, was counteracted by infliximab treatment. Reporter gene assays showed significantly reduced CDX2 and MEP1A activity upon TNF-α stimulation. Finally, TNF-α impaired the ability of CDX2 to interact and activate its own, as well as the MEP1A expression. CONCLUSIONS: The present results indicate that a TNF-α-mediated down-regulation of CDX2 can be related to suppressed expression of MEP1A during intestinal inflammation.


Asunto(s)
Colitis Ulcerosa/metabolismo , Proteínas de Homeodominio/biosíntesis , Enfermedades Inflamatorias del Intestino/metabolismo , Metaloendopeptidasas/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo , Adulto , Animales , Anticuerpos Monoclonales/farmacología , Factor de Transcripción CDX2 , Línea Celular , Inmunoprecipitación de Cromatina , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/genética , Colitis Ulcerosa/patología , Sulfato de Dextran , Femenino , Proteínas de Homeodominio/genética , Humanos , Enfermedades Inflamatorias del Intestino/genética , Enfermedades Inflamatorias del Intestino/patología , Infliximab , Mucosa Intestinal/metabolismo , Masculino , Metaloendopeptidasas/genética , Ratones , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/metabolismo , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
17.
Am J Physiol Gastrointest Liver Physiol ; 302(3): G277-86, 2012 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-22094602

RESUMEN

Upon developmental or environmental cues, the composition of transcription factors in a transcriptional regulatory network is deeply implicated in controlling the signature of the gene expression and thereby specifies the cell or tissue type. Novel methods including ChIP-chip and ChIP-Seq have been applied to analyze known transcription factors and their interacting regulatory DNA elements in the intestine. The intestine is an example of a dynamic tissue where stem cells in the crypt proliferate and undergo a differentiation process toward the villus. During this differentiation process, specific regulatory networks of transcription factors are activated to target specific genes, which determine the intestinal cell fate. The expanding genomewide mapping of transcription factor binding sites and construction of transcriptional regulatory networks provide new insight into how intestinal differentiation occurs. This review summarizes the current overview of the transcriptional regulatory networks driving epithelial differentiation in adult intestine. The novel technologies that have been implied to study these networks are presented and their prospects for implications in future research are also addressed.


Asunto(s)
Redes Reguladoras de Genes/fisiología , Mucosa Intestinal/metabolismo , Factores de Transcripción/metabolismo , Animales , Diferenciación Celular/fisiología , Inmunoprecipitación de Cromatina/métodos , Humanos , Mucosa Intestinal/citología , Especificidad de Órganos
18.
Biochim Biophys Acta ; 1812(3): 283-9, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21126581

RESUMEN

Many transcription factors are known to control transcription at several promoters, while others are only active at a few places. However, due to their importance in controlling cellular functions, aberrant transcription factor function and inappropriate gene regulation have been shown to play a causal role in a large number of diseases and developmental disorders. Inflammatory bowel disease (IBD) is characterized by a chronically inflamed mucosa caused by dysregulation of the intestinal immune homeostasis. The aetiology of IBD is thought to be a combination of genetic and environmental factors, including luminal bacteria. The Caudal-related homeobox transcription factor 2 (CDX2) is critical in early intestinal differentiation and has been implicated as a master regulator of the intestinal homeostasis and permeability in adults. When expressed, CDX2 modulates a diverse set of processes including cell proliferation, differentiation, cell adhesion, migration, and tumorigenesis. In addition to these critical cellular processes, there is increasing evidence for linking CDX2 to intestinal inflammation. The aim of the present paper was to review the current knowledge of CDX2 in regulation of the intestinal homeostasis and further to reveal its potential role in inflammation.


Asunto(s)
Proteínas de Homeodominio/fisiología , Homeostasis , Enfermedades Inflamatorias del Intestino/metabolismo , Mucosa Intestinal/metabolismo , Factor de Transcripción CDX2 , Humanos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...