Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Int J Cancer ; 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38850108

RESUMEN

Despite advances in early detection and treatment strategies, breast cancer recurrence and mortality remain a significant health issue. Recent insights suggest the prognostic potential of microscopically healthy mammary gland, in the vicinity of the breast lesion. Nonetheless, a comprehensive understanding of the gene expression profiles in these tissues and their relationship to patient outcomes remain missing. Furthermore, the increasing trend towards breast-conserving surgery may inadvertently lead to the retention of existing cancer-predisposing mutations within the normal mammary gland. This study assessed the transcriptomic profiles of 242 samples from 83 breast cancer patients with unfavorable outcomes, including paired uninvolved mammary gland samples collected at varying distances from primary lesions. As a reference, control samples from 53 mammoplasty individuals without cancer history were studied. A custom panel of 634 genes linked to breast cancer progression and metastasis was employed for expression profiling, followed by whole-transcriptome verification experiments and statistical analyses to discern molecular signatures and their clinical relevance. A distinct gene expression signature was identified in uninvolved mammary gland samples, featuring key cellular components encoding keratins, CDH1, CDH3, EPCAM cell adhesion proteins, matrix metallopeptidases, oncogenes, tumor suppressors, along with crucial genes (FOXA1, RAB25, NRG1, SPDEF, TRIM29, and GABRP) having dual roles in cancer. Enrichment analyses revealed disruptions in epithelial integrity, cell adhesion, and estrogen signaling. This signature, named KAOS for Keratin-Adhesion-Oncogenes-Suppressors, was significantly associated with reduced tumor size but increased mortality rates. Integrating molecular assessment of non-malignant mammary tissue into disease management could enhance survival prediction and facilitate personalized patient care.

2.
J Transl Med ; 21(1): 270, 2023 04 21.
Artículo en Inglés | MEDLINE | ID: mdl-37081484

RESUMEN

BACKGROUND: Visium Spatial Gene Expression (ST) is a method combining histological spatial information with transcriptomics profiles directly from tissue sections. The use of spatial information has made it possible to discover new modes of gene expression regulations. However, in the ST experiment, the nucleus size of cells may exceed the thickness of a tissue slice. This may, in turn, negatively affect comprehensive capturing the transcriptomics profile in a single slice, especially for tissues having large differences in the size of nuclei. METHODS: Here, we defined the effect of Consecutive Slices Data Integration (CSDI) on unveiling accurate spot clustering and deconvolution of spatial transcriptomic spots in human postmortem brains. By considering the histological information as reference, we assessed the improvement of unsupervised clustering and single nuclei RNA-seq and ST data integration before and after CSDI. RESULTS: Apart from the escalated number of defined clusters representing neuronal layers, the pattern of clusters in consecutive sections was concordant only after CSDI. Besides, the assigned cell labels to spots matches the histological pattern of tissue sections after CSDI. CONCLUSION: CSDI can be applied to investigate consecutive sections studied with ST in the human cerebral cortex, avoiding misinterpretation of spot clustering and annotation, increasing accuracy of cell recognition as well as improvement in uncovering the layers of grey matter in the human brain.


Asunto(s)
Perfilación de la Expresión Génica , Transcriptoma , Humanos , Transcriptoma/genética , RNA-Seq , Encéfalo , Comunicación Celular
3.
Hum Mutat ; 43(1): 74-84, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34747535

RESUMEN

Constitutional LZTR1 or SMARCB1 pathogenic variants (PVs) have been found in ∼86% of familial and ∼40% of sporadic schwannomatosis cases. Hence, we performed massively parallel sequencing of the entire LZTR1, SMARCB1, and NF2 genomic loci in 35 individuals with schwannomas negative for constitutional first-hit PVs in the LZTR1/SMARCB1/NF2 coding sequences; however, with 22q deletion and/or a different NF2 PV in each tumor, including six cases with only one tumor available. Furthermore, we verified whether any other LZTR1/SMARCB1/NF2 (likely) PVs could be found in 16 cases carrying a SMARCB1 constitutional variant in the 3'-untranslated region (3'-UTR) c.*17C>T, c.*70C>T, or c.*82C>T. As no additional variants were found, functional studies were performed to clarify the effect of these 3'-UTR variants on the transcript. The 3'-UTR variants c.*17C>T and c.*82C>T showed pathogenicity by negatively affecting the SMARCB1 transcript level. Two novel deep intronic SMARCB1 variants, c.500+883T>G and c.500+887G>A, resulting in out-of-frame missplicing of intron 4, were identified in two unrelated individuals. Further resequencing of the entire repeat-masked genomics sequences of chromosome 22q in individuals negative for PVs in the SMARCB1/LZTR1/NF2 coding- and noncoding regions revealed five potential schwannomatosis-predisposing candidate genes, that is, MYO18B, NEFH, SGSM1, SGSM3, and SBF1, pending further verification.


Asunto(s)
Neurilemoma , Neurofibromatosis , Cromosomas , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Neurilemoma/genética , Neurilemoma/patología , Neurofibromatosis/genética , Proteína SMARCB1/genética , Factores de Transcripción/genética
4.
Cell Mol Life Sci ; 78(8): 4019-4033, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33837451

RESUMEN

Epidemiological investigations show that mosaic loss of chromosome Y (LOY) in leukocytes is associated with earlier mortality and morbidity from many diseases in men. LOY is the most common acquired mutation and is associated with aberrant clonal expansion of cells, yet it remains unclear whether this mosaicism exerts a direct physiological effect. We studied DNA and RNA from leukocytes in sorted- and single-cells in vivo and in vitro. DNA analyses of sorted cells showed that men diagnosed with Alzheimer's disease was primarily affected with LOY in NK cells whereas prostate cancer patients more frequently displayed LOY in CD4 + T cells and granulocytes. Moreover, bulk and single-cell RNA sequencing in leukocytes allowed scoring of LOY from mRNA data and confirmed considerable variation in the rate of LOY across individuals and cell types. LOY-associated transcriptional effect (LATE) was observed in ~ 500 autosomal genes showing dysregulation in leukocytes with LOY. The fraction of LATE genes within specific cell types was substantially larger than the fraction of LATE genes shared between different subsets of leukocytes, suggesting that LOY might have pleiotropic effects. LATE genes are involved in immune functions but also encode proteins with roles in other diverse biological processes. Our findings highlight a surprisingly broad role for chromosome Y, challenging the view of it as a "genetic wasteland", and support the hypothesis that altered immune function in leukocytes could be a mechanism linking LOY to increased risk for disease.


Asunto(s)
Enfermedad de Alzheimer/genética , Cromosomas Humanos Y , Mosaicismo , Neoplasias de la Próstata/genética , Linfocitos T CD4-Positivos/metabolismo , Regulación de la Expresión Génica , Humanos , Células Asesinas Naturales/metabolismo , Leucocitos/metabolismo , Masculino
5.
Int J Mol Sci ; 22(11)2021 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-34200045

RESUMEN

Ischemic stroke is a disturbance in cerebral blood flow caused by brain tissue ischemia and hypoxia. We optimized a multifactorial in vitro model of acute ischemic stroke using rat primary neural cultures. This model was exploited to investigate the pro-viable activity of cell-penetrating peptides: arginine-rich Tat(49-57)-NH2 (R49KKRRQRRR57-amide) and its less basic analogue, PTD4 (Y47ARAAARQARA57-amide). Our model included glucose deprivation, oxidative stress, lactic acidosis, and excitotoxicity. Neurotoxicity of these peptides was excluded below a concentration of 50 µm, and PTD4-induced pro-survival was more pronounced. Circular dichroism spectroscopy and molecular dynamics (MD) calculations proved potential contribution of the peptide conformational properties to neuroprotection: in MD, Tat(49-57)-NH2 adopted a random coil and polyproline type II helical structure, whereas PTD4 adopted a helical structure. In an aqueous environment, the peptides mostly adopted a random coil conformation (PTD4) or a polyproline type II helical (Tat(49-57)-NH2) structure. In 30% TFE, PTD4 showed a tendency to adopt a helical structure. Overall, the pro-viable activity of PTD4 was not correlated with the arginine content but rather with the peptide's ability to adopt a helical structure in the membrane-mimicking environment, which enhances its cell membrane permeability. PTD4 may act as a leader sequence in novel drugs for the treatment of acute ischemic stroke.


Asunto(s)
Isquemia Encefálica/prevención & control , Péptidos de Penetración Celular/farmacología , Modelos Animales de Enfermedad , Accidente Cerebrovascular Isquémico/prevención & control , Neuronas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Animales , Isquemia Encefálica/etiología , Isquemia Encefálica/patología , Permeabilidad de la Membrana Celular , Femenino , Accidente Cerebrovascular Isquémico/etiología , Accidente Cerebrovascular Isquémico/patología , Ratas , Ratas Wistar
6.
Molecules ; 25(12)2020 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-32585846

RESUMEN

Regeneration and wound healing are vital to tissue homeostasis and organism survival. One of the biggest challenges of today's science and medicine is finding methods and factors to stimulate these processes in the human body. Effective solutions to promote regenerative responses will accelerate advances in tissue engineering, regenerative medicine, transplantology, and a number of other clinical specialties. In this study, we assessed the potential efficacy of a synthetic hexapeptide, RDKVYR, for the stimulation of tissue repair and wound healing. The hexapeptide is marketed under the name "Imunofan" (IM) as an immunostimulant. IM displayed stability in aqueous solutions, while in plasma it was rapidly bound by albumins. Structural analyses demonstrated the conformational flexibility of the peptide. Tests in human fibroblast and keratinocyte cell lines showed that IM exerted a statistically significant (p < 0.05) pro-proliferative activity (30-40% and 20-50% increase in proliferation of fibroblast and keratinocytes, respectively), revealed no cytotoxicity over a vast range of concentrations (p < 0.05), and had no allergic properties. IM was found to induce significant transcriptional responses, such as enhanced activity of genes involved in active DNA demethylation (p < 0.05) in fibroblasts and activation of genes involved in immune responses, migration, and chemotaxis in adipose-derived stem cells derived from surgery donors. Experiments in a model of ear pinna injury in mice indicated that IM moderately promoted tissue repair (8% in BALB/c and 36% in C57BL/6 in comparison to control).


Asunto(s)
Proliferación Celular/efectos de los fármacos , Oligopéptidos/farmacología , Piel/patología , Cicatrización de Heridas , Albúminas/metabolismo , Animales , Basófilos/efectos de los fármacos , Muerte Celular/efectos de los fármacos , Línea Celular , Quimiotaxis/efectos de los fármacos , Citocinas/metabolismo , Metilación de ADN/efectos de los fármacos , Oído/patología , Fibroblastos/citología , Fibroblastos/efectos de los fármacos , Células HaCaT/citología , Células HaCaT/efectos de los fármacos , Humanos , Inyecciones Subcutáneas , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Oligopéptidos/sangre , Oligopéptidos/química , Oligopéptidos/metabolismo , Estabilidad Proteica/efectos de los fármacos , Células Madre/citología , Células Madre/efectos de los fármacos , Transcripción Genética/efectos de los fármacos
7.
Am J Hum Genet ; 97(2): 238-49, 2015 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-26189818

RESUMEN

Genomic rearrangements can cause both Mendelian and complex disorders. Currently, several major mechanisms causing genomic rearrangements, such as non-allelic homologous recombination (NAHR), non-homologous end joining (NHEJ), fork stalling and template switching (FoSTeS), and microhomology-mediated break-induced replication (MMBIR), have been proposed. However, to what extent these mechanisms contribute to gene-specific pathogenic copy-number variations (CNVs) remains understudied. Furthermore, few studies have resolved these pathogenic alterations at the nucleotide-level. Accordingly, our aim was to explore which mechanisms contribute to a large, unique set of locus-specific non-recurrent genomic rearrangements causing the genetic neurocutaneous disorder neurofibromatosis type 1 (NF1). Through breakpoint-spanning PCR as well as array comparative genomic hybridization, we have identified the breakpoints in 85 unrelated individuals carrying an NF1 intragenic CNV. Furthermore, we characterized the likely rearrangement mechanisms of these 85 CNVs, along with those of two additional previously published NF1 intragenic CNVs. Unlike the most typical recurrent rearrangements mediated by flanking low-copy repeats (LCRs), NF1 intragenic rearrangements vary in size, location, and rearrangement mechanisms. We propose the DNA-replication-based mechanisms comprising both FoSTeS and/or MMBIR and serial replication stalling to be the predominant mechanisms leading to NF1 intragenic CNVs. In addition to the loop within a 197-bp palindrome located in intron 40, four Alu elements located in introns 1, 2, 3, and 50 were also identified as intragenic-rearrangement hotspots within NF1.


Asunto(s)
Variaciones en el Número de Copia de ADN/genética , Neurofibromatosis 1/genética , Neurofibromina 1/genética , Puntos de Rotura del Cromosoma , Hibridación Genómica Comparativa , Análisis Mutacional de ADN , Humanos , Hibridación Fluorescente in Situ , Reacción en Cadena de la Polimerasa/métodos
8.
Genome Res ; 25(10): 1521-35, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26430163

RESUMEN

Sporadic breast cancer (SBC) is a common disease without robust means of early risk prediction in the population. We studied 282 females with SBC, focusing on copy number aberrations in cancer-free breast tissue (uninvolved margin, UM) outside the primary tumor (PT). In total, 1162 UMs (1-14 per breast) were studied. Comparative analysis between UM(s), PT(s), and blood/skin from the same patient as a control is the core of the study design. We identified 108 patients with at least one aberrant UM, representing 38.3% of cases. Gains in gene copy number were the principal type of mutations in microscopically normal breast cells, suggesting that oncogenic activation of genes via increased gene copy number is a predominant mechanism for initiation of SBC pathogenesis. The gain of ERBB2, with overexpression of HER2 protein, was the most common aberration in normal cells. Five additional growth factor receptor genes (EGFR, FGFR1, IGF1R, LIFR, and NGFR) also showed recurrent gains, and these were occasionally present in combination with the gain of ERBB2. All the aberrations found in the normal breast cells were previously described in cancer literature, suggesting their causative, driving role in pathogenesis of SBC. We demonstrate that analysis of normal cells from cancer patients leads to identification of signatures that may increase risk of SBC and our results could influence the choice of surgical intervention to remove all predisposing cells. Early detection of copy number gains suggesting a predisposition toward cancer development, long before detectable tumors are formed, is a key to the anticipated shift into a preventive paradigm of personalized medicine for breast cancer.


Asunto(s)
Neoplasias de la Mama/genética , Mama/anatomía & histología , Mutación , Adulto , Anciano , Anciano de 80 o más Años , Mama/patología , Neoplasias de la Mama/patología , Estudios de Cohortes , Análisis Mutacional de ADN , Femenino , Dosificación de Gen , Genes erbB-2 , Predisposición Genética a la Enfermedad , Genotipo , Humanos , Persona de Mediana Edad , Receptor ErbB-2/genética , Receptores de Factores de Crecimiento/genética , Factores de Riesgo
9.
Neurogenetics ; 18(3): 169-174, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28285357

RESUMEN

Multiplex ligation-dependent probe amplification (MLPA) has been widely used to identify copy-number variations (CNVs), but MLPA's sensitivity and specificity in mosaic CNV detection are largely unknown. Here, we present two mosaic deletions identified by MLPA as NF1 deletion of exons 17-21 and NF2 deletion of exons 9-10. Through cDNA analysis, genomic breakpoint-spanning PCR and Sanger sequencing, we found however both NF1 and NF2 deletions are each composed of two consecutive deletions, which cannot be differentiated by MLPA. Importantly, these consecutive deletions are most likely originating from a single genomic rearrangement and have been preserved independently in different populations of cells.


Asunto(s)
Variaciones en el Número de Copia de ADN/genética , Exones/genética , Neurofibromatosis 1/genética , Neurofibromatosis 2/genética , Eliminación de Gen , Genoma Humano , Genómica , Humanos , Mutación/genética , Reacción en Cadena de la Polimerasa/métodos
10.
Genes Chromosomes Cancer ; 55(11): 877-89, 2016 11.
Artículo en Inglés | MEDLINE | ID: mdl-27295517

RESUMEN

The molecular bases of miR-182 deregulation in epithelial ovarian cancers (EOCs) remain unknown and its diagnostic or prognostic role in EOCs is still unclear. We performed miR-182 expression analysis using a microarray approach and real-time PCR (qPCR). We also used array comparative genomic hybridization and methylated DNA immunoprecipitation to study copy number changes and methylation aberrations within coding locus/promoter sequences of miR-182 in EOC tissues, respectively. We have found that miR-182 expression is significantly increased in EOC (P < 0.00001) and that higher miR-182 expression in EOC is linked with significantly shorter overall survival (P = 0.026). The methylation of miR-182 promoter was significantly associated with lower miR-182 expression in EOC tissues (P = 0.045). miR-182 over-expression is connected with copy number (CN) gains of this miRNA coding sequences in EOC (P = 0.002), and the number of PRDM5 copies is significantly and inversely correlated with miR-182 expression evaluated by qPCR (R = -0.615, P = 0.009). We conclude that the aberrant miR-182 expression in EOC may be due to CN gains within its coding locus. The miR-182 promoter is rarely methylated in EOC, and its methylation status is associated with lower miR-182 expression. Deletion of the PRDM5 locus may play a supportive role in miR-182 overexpression in EOC. miR-182 is an unfavorable prognostic factor in EOC. © 2016 Wiley Periodicals, Inc.


Asunto(s)
Biomarcadores de Tumor/genética , Proteínas de Unión al ADN/genética , MicroARNs/genética , Neoplasias Ováricas/genética , Factores de Transcripción/genética , Adulto , Anciano , Biomarcadores de Tumor/biosíntesis , Proliferación Celular/genética , Hibridación Genómica Comparativa , Metilación de ADN/genética , Supervivencia sin Enfermedad , Femenino , Regulación Neoplásica de la Expresión Génica/genética , Humanos , MicroARNs/biosíntesis , Persona de Mediana Edad , Neoplasias Ováricas/patología , Pronóstico , Regiones Promotoras Genéticas
11.
FASEB J ; 29(4): 1467-79, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25550463

RESUMEN

Hypoxia-inducible factors (HIFs) 1 and 2 are dimeric α/ß transcription factors that regulate cellular responses to low oxygen. HIF-1 is induced first, whereas HIF-2 is associated with chronic hypoxia. To determine how HIF1A mRNA, the inducible subunit of HIF-1, is regulated during hypoxia, we followed HIF1A mRNA levels in primary HUVECs over 24 hours using quantitative PCR. HIF1A and VEGF A (VEGFA) mRNA, a transcriptional target of HIF-1, increased ∼ 2.5- and 8-fold at 2-4 hours, respectively. To determine how the mRNAs were regulated, we identified a microRNA (miRNA), miR-429, that destabilized HIF1A message and decreased VEGFA mRNA by inhibiting HIF1A. Target protector analysis, which interferes with miRNA-mRNA complex formation, confirmed that miR-429 targeted HIF1A message. Desferoxamine treatment, which inhibits the hydroxylases that promote HIF-1α protein degradation, stabilized HIF-1 activity during normoxic conditions and elevated miR-429 levels, demonstrating that HIF-1 promotes miR-429 expression. RNA-sequencing-based transcriptome analysis indicated that inhibition of miRNA-429 in HUVECs up-regulated 209 mRNAs, a number of which regulate angiogenesis. The results demonstrate that HIF-1 is in a negative regulatory loop with miR-429, that miR-429 attenuates HIF-1 activity by decreasing HIF1A message during the early stages of hypoxia before HIF-2 is activated, and this regulatory network helps explain the HIF-1 transition to HIF-2 during chronic hypoxia in endothelial cells.


Asunto(s)
Hipoxia de la Célula/genética , Hipoxia de la Célula/fisiología , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , MicroARNs/genética , MicroARNs/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Retroalimentación Fisiológica , Células Endoteliales de la Vena Umbilical Humana , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/antagonistas & inhibidores , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Prolina Dioxigenasas del Factor Inducible por Hipoxia/genética , Oxigenasas de Función Mixta/genética , Modelos Biológicos , Neovascularización Fisiológica , Proteolisis , Estabilidad del ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , Proteínas Represoras/genética , Factor A de Crecimiento Endotelial Vascular/genética
12.
Cell Mol Biol Lett ; 21: 23, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-28536625

RESUMEN

Synonymous or silent mutations are often overlooked in genetic analyses for disease-causing mutations unless they are directly associated with potential splicing defects. More recent studies, however, indicate that some synonymous single polynucleotide polymorphisms (sSNPs) are associated with changes in protein expression, and in some cases, protein folding and function. The impact of codon usage and mRNA structural changes on protein translation rates and how they can affect protein structure and function is just beginning to be appreciated. Examples are given here that demonstrate how synonymous mutations alter the translational kinetics and protein folding and/or function. The mechanism for how this occurs is based on a model in which codon usage modulates the translational rate by introducing pauses caused by nonoptimal or rare codons or by introducing changes in the mRNA structure, and this in turn influences co-translational folding. Two examples of this include the multidrug resistance protein (p-glycoprotein) and the cystic fibrosis transmembrane conductance regulator gene (CFTR). CFTR is also used here as a model to illustrate how synonymous mutations can be examined using in silico predictive methods to identify which sSNPs have the potential to change protein structure. The methodology described here can be used to help identify "non-silent" synonymous mutations in other genes.


Asunto(s)
Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Polimorfismo de Nucleótido Simple , Pliegue de Proteína , Mutación Silenciosa , Simulación por Computador , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Humanos
13.
Hum Mutat ; 36(11): 1088-99, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26219265

RESUMEN

Somatic mosaicism for DNA copy-number alterations (SMC-CNAs) is defined as gain or loss of chromosomal segments in somatic cells within a single organism. As cells harboring SMC-CNAs can undergo clonal expansion, it has been proposed that SMC-CNAs may contribute to the predisposition of these cells to genetic disease including cancer. Herein, the gross genomic alterations (>500 kbp) were characterized in uninvolved mammary glandular tissue from 59 breast cancer patients and matched samples of primary tumors and lymph node metastases. Array-based comparative genomic hybridization showed 10% (6/59) of patients harbored one to 359 large SMC-CNAs (mean: 1,328 kbp; median: 961 kbp) in a substantial portion of glandular tissue cells, distal from the primary tumor site. SMC-CNAs were partially recurrent in tumors, albeit with considerable contribution of stochastic SMC-CNAs indicating genomic destabilization. Targeted resequencing of 301 known predisposition and somatic driver loci revealed mutations and rare variants in genes related to maintenance of genomic integrity: BRCA1 (p.Gln1756Profs*74, p.Arg504Cys), BRCA2 (p.Asn3124Ile), NCOR1 (p.Pro1570Glnfs*45), PALB2 (p.Ser500Pro), and TP53 (p.Arg306*). Co-occurrence of gross SMC-CNAs along with point mutations or rare variants in genes responsible for safeguarding genomic integrity highlights the temporal and spatial neoplastic potential of uninvolved glandular tissue in breast cancer patients.


Asunto(s)
Neoplasias de la Mama/genética , Variaciones en el Número de Copia de ADN , Inestabilidad Genómica , Mutación , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor , Neoplasias de la Mama/patología , Hibridación Genómica Comparativa , Análisis Mutacional de ADN , Femenino , Genes BRCA1 , Genes BRCA2 , Estudios de Asociación Genética , Sitios Genéticos , Predisposición Genética a la Enfermedad , Humanos , Persona de Mediana Edad , Clasificación del Tumor , Metástasis de la Neoplasia , Estadificación de Neoplasias , Reproducibilidad de los Resultados , Carga Tumoral
14.
Biochim Biophys Acta ; 1839(11): 1341-50, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25111868

RESUMEN

BACKGROUND: Signal transducer and activator of transcription 3 (STAT3) is constitutively activated in many human tumors, including gliomas, and regulates the expression of genes implicated in proliferation, survival, apoptosis, angiogenesis and immune regulation. Only a small fraction of those genes has been proven to be direct STAT3 targets. In gliomas, STAT3 can play tumor suppressive or oncogenic roles depending on the tumor genetic background with target genes being largely unknown. RESULTS: We used chromatin immunoprecipitation, promoter microarrays and deep sequencing to assess the genome-wide occupancy of phospho (p)-Stat3 and epigenetic modifications of H3K4me3 and H3ac in C6 glioma cells. This combined assessment identified a list of 1200 genes whose promoters have both Stat3 binding sites and epigenetic marks characteristic for actively transcribed genes. The Stat3 and histone markings data were also intersected with a set of microarray data from C6 glioma cells after inhibition of Jak2/Stat3 signaling. Subsequently, we found 284 genes characterized by p-Stat3 occupancy, activating histone marks and transcriptional changes. Novel genes were screened for their potential involvement in oncogenesis, and the most interesting hits were verified by ChIP-PCR and STAT3 knockdown in human glioma cells. CONCLUSIONS: Non-random association between silent genes, histone marks and p-Stat3 binding near transcription start sites was observed, consistent with its repressive role in transcriptional regulation of target genes in glioma cells with specific genetic background.


Asunto(s)
Epigénesis Genética , Regulación Neoplásica de la Expresión Génica , Glioma/genética , Glioma/metabolismo , Factor de Transcripción STAT3/metabolismo , Transcriptoma , Animales , Sitios de Unión/genética , Inmunoprecipitación de Cromatina , Análisis de Secuencia por Matrices de Oligonucleótidos , Fosforilación , Unión Proteica , Ratas , Factor de Transcripción STAT3/fisiología , Sitio de Iniciación de la Transcripción , Células Tumorales Cultivadas
15.
Am J Hum Genet ; 90(2): 217-28, 2012 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-22305530

RESUMEN

Structural variations are among the most frequent interindividual genetic differences in the human genome. The frequency and distribution of de novo somatic structural variants in normal cells is, however, poorly explored. Using age-stratified cohorts of 318 monozygotic (MZ) twins and 296 single-born subjects, we describe age-related accumulation of copy-number variation in the nuclear genomes in vivo and frequency changes for both megabase- and kilobase-range variants. Megabase-range aberrations were found in 3.4% (9 of 264) of subjects ≥60 years old; these subjects included 78 MZ twin pairs and 108 single-born individuals. No such findings were observed in 81 MZ pairs or 180 single-born subjects who were ≤55 years old. Recurrent region- and gene-specific mutations, mostly deletions, were observed. Longitudinal analyses of 43 subjects whose data were collected 7-19 years apart suggest considerable variation in the rate of accumulation of clones carrying structural changes. Furthermore, the longitudinal analysis of individuals with structural aberrations suggests that there is a natural self-removal of aberrant cell clones from peripheral blood. In three healthy subjects, we detected somatic aberrations characteristic of patients with myelodysplastic syndrome. The recurrent rearrangements uncovered here are candidates for common age-related defects in human blood cells. We anticipate that extension of these results will allow determination of the genetic age of different somatic-cell lineages and estimation of possible individual differences between genetic and chronological age. Our work might also help to explain the cause of an age-related reduction in the number of cell clones in the blood; such a reduction is one of the hallmarks of immunosenescence.


Asunto(s)
Células Sanguíneas/fisiología , Variaciones en el Número de Copia de ADN/genética , Genoma Humano , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Niño , Estudios de Cohortes , Femenino , Humanos , Individualidad , Estudios Longitudinales , Persona de Mediana Edad , Mutación/genética , Síndromes Mielodisplásicos/sangre , Síndromes Mielodisplásicos/genética , Gemelos Monocigóticos/genética , Adulto Joven
16.
Hum Mutat ; 35(7): 891-8, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24760680

RESUMEN

Palindromic sequences can form hairpin structures or cruciform extrusions, which render them susceptible to genomic rearrangements. A 197-bp long palindromic AT-rich repeat (PATRR17) is located within intron 40 of the neurofibromatosis type 1 (NF1) gene (17q11.2). Through comprehensive NF1 analysis, we identified six unrelated patients with a rearrangement involving intron 40 (five deletions and one reciprocal translocation t(14;17)(q32;q11.2)). We hypothesized that PATRR17 may be involved in these rearrangements thereby causing NF1. Breakpoint cloning revealed that PATRR17 was indeed involved in all of the rearrangements. As microhomology was present at all breakpoint junctions of the deletions identified, and PATRR17 partner breakpoints were located within 7.1 kb upstream of PATRR17, fork stalling and template switching/microhomology-mediated break-induced replication was the most likely rearrangement mechanism. For the reciprocal translocation case, a 51 bp insertion at the translocation breakpoints mapped to a short sequence within PATRR17, proximal to the breakpoint, suggesting a multiple stalling and rereplication process, in contrast to previous studies indicating a purely replication-independent mechanism for PATRR-mediated translocations. In conclusion, we show evidence that PATRR17 is a hotspot for pathogenic intragenic deletions within the NF1 gene and suggest a novel replication-dependent mechanism for PATRR-mediated translocation.


Asunto(s)
Replicación del ADN , Secuencias Invertidas Repetidas , Neurofibromatosis 1/genética , Neurofibromina 1/química , Neurofibromina 1/genética , Recombinación Genética , Secuencia Rica en At , Secuencia de Bases , Puntos de Rotura del Cromosoma , Cromosomas Humanos Par 14 , Cromosomas Humanos Par 17 , Humanos , Datos de Secuencia Molecular , Eliminación de Secuencia , Translocación Genética
17.
Life Sci ; 351: 122761, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38866216

RESUMEN

Mesenchymal Stromal Cells (MSCs) offer tremendous potential for the treatment of various diseases and their healing properties have been explored in hundreds of clinical trials. These trails primarily focus on immunological and neurological disorders, as well as regenerative medicine. Adipose tissue is a rich source of mesenchymal stromal cells and methods to obtain and culture adipose-derived MSCs (AD-MSCs) have been well established. Promising results from pre-clinical testing of AD-MSCs activity prompted clinical trials that further led to the approval of AD-MSCs for the treatment of complex perianal fistulas in Crohn's disease and subcutaneous tissue defects. However, AD-MSC heterogeneity along with various manufacturing protocols or different strategies to boost their activity create the need for standardized quality control procedures and safety assessment of the intended cell product. High-resolution transcriptomic methods have been recently gaining attention, as they deliver insight into gene expression profiles of individual cells, helping to deconstruct cellular hierarchy and differentiation trajectories, and to understand cell-cell interactions within tissues. This article presents a comprehensive overview of completed clinical trials evaluating the safety and efficacy of AD-MSC treatment, together with current single-cell studies of human AD-MSC. Furthermore, our work emphasizes the increasing significance of single-cell research in elucidating the mechanisms of cellular action and predicting their therapeutic effects.

18.
Biomark Insights ; 19: 11772719241257739, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38911905

RESUMEN

Background: Colorectal cancer (CRC) prognosis is determined by the disease stage with low survival rates for advanced stages. Current CRC screening programs are mainly using colonoscopy, limited by its invasiveness and high cost. Therefore, non-invasive, cost-effective, and accurate alternatives are urgently needed. Objective and design: This retrospective multi-center plasma proteomics study was performed to identify potential blood-based biomarkers in 36 CRC patients and 26 healthy volunteers by high-resolution mass spectrometry proteomics followed by the validation in an independent CRC cohort (60 CRC patients and 44 healthy subjects) of identified selected biomarkers. Results: Among the 322 identified plasma proteins, 37 were changed between CRC patients and healthy volunteers and were associated with the complement cascade, cholesterol metabolism, and SERPIN family members. Increased levels in CRC patients of the complement proteins C1QB, C4B, and C5 as well as pro-inflammatory proteins, lipopolysaccharide-binding protein (LBP) and serum amyloid A4, constitutive (SAA4) were revealed for first time. Importantly, increased level of C5 was verified in an independent validation CRC cohort. Increased C4B and C8A levels were correlated with cancer-associated inflammation and CRC progression, while cancer-associated inflammation was linked to the acute-phase reactant leucine-rich alpha-2-glycoprotein 1 (LRG1) and ceruloplasmin. Moreover, a 4-protein signature including C4B, C8A, apolipoprotein C2 (APO) C2, and immunoglobulin heavy constant gamma 2 was changed between early and late CRC stages. Conclusion: Our results suggest that C5 could be a potential biomarker for CRC diagnosis. Further validation studies will aid the application of these new potential biomarkers to improve CRC diagnosis and patient care.

19.
Cancers (Basel) ; 16(5)2024 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-38473323

RESUMEN

Bladder urothelial carcinoma (BLCA) is the 10th most common cancer with a low survival rate and strong male bias. We studied the field cancerization in BLCA using multi-sample- and multi-tissue-per-patient protocol for sensitive detection of autosomal post-zygotic chromosomal alterations and loss of chromosome Y (LOY). We analysed 277 samples of histologically normal urothelium, 145 tumors and 63 blood samples from 52 males and 15 females, using the in-house adapted Mosaic Chromosomal Alterations (MoChA) pipeline. This approach allows identification of the early aberrations in urothelium from BLCA patients. Overall, 45% of patients exhibited at least one alteration in at least one normal urothelium sample. Recurrence analysis resulted in 16 hotspots composed of either gains and copy number neutral loss of heterozygosity (CN-LOH) or deletions and CN-LOH, encompassing well-known and new BLCA cancer driver genes. Conservative assessment of LOY showed 29%, 27% and 18% of LOY-cells in tumors, blood and normal urothelium, respectively. We provide a proof of principle that our approach can characterize the earliest alterations preconditioning normal urothelium to BLCA development. Frequent LOY in blood and urothelium-derived tissues suggest its involvement in BLCA.

20.
Mol Genet Genomics ; 288(10): 469-81, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23824080

RESUMEN

The sporulation process is a complex genetic developmental program leading to profound changes in global gene expression profile. In this work, we have applied genome-wide microarray approach for transcriptional profiling of Bacillus subtilis strain lacking a gene coding for PrpE protein phosphatase. This protein was previously shown to be involved in the regulation of germination of B. subtilis spores. Moreover, the deletion of prpE gene resulted in changing the resistance properties of spores. Our results provide genome-wide insight into the influence of this protein phosphatase on the physiology of B. subtilis cells. Although the precise role of PrpE in shaping the observed phenotype of ΔprpE mutant strain still remains beyond the understanding, our experiments brought observations of possible indirect implication of this protein in the regulation of cell motility and chemotaxis, as well as the development of competence. Surprisingly, prpE-deleted cells showed elevated level of general stress response, which turned out to be growth medium specific.


Asunto(s)
Bacillus subtilis/genética , Bacillus subtilis/fisiología , Perfilación de la Expresión Génica , Genoma Bacteriano/genética , Análisis por Conglomerados , Eliminación de Gen , Análisis por Micromatrices , Fosfoproteínas Fosfatasas/deficiencia , Especificidad de la Especie , Esporas Bacterianas/fisiología , beta-Galactosidasa/metabolismo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA