Sample records for RESTAURACION DEL DNA (dna repair)
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1

REPARACIÓN DEL ADN: UNA POSIBLE RELACIÓN ENTRE LA DEFICIENCIA DE FOLATO Y LA MUERTE NEURONAL/ DNA Repair: A Link Between Folate Deficiency and Neuronal Cell Death

RAMÍREZ, NELSON J; ARBOLEDA, GONZALO; ARBOLEDA, HUMBERTO
2007-11-01

Resumen en español El presente artículo explora el papel que desempeña el folato como conocido metabolito del ciclo de un carbono (OCM, del inglés onecarbon metabolism) en la alteración de la integridad de las células nerviosas. Aquí se discute evidencia reciente de la literatura que muestra la reparación del ADN como un proceso relacionado con la apoptosis neuronal inducida por ausencia de folato. Resumen en inglés This essay explores the role of folate in disruption of neural cell integrity. Here, it is discussed recent evidence which shows DNA reparation as a process related to neuronal apoptosis induced by folate depletion.

Scientific Electronic Library Online (Spanish)

2

Detección de mutaciones de los genes hMLH1 y hMSH2 del sistema de reparación de malos apareamientos del ADN en familias colombianas sospechosas cáncer colorrectal no polipósico hereditario (síndrome de Lynch)/ Detection mutations in the DNA mismatch repair genes of hMLH1 and hMSH2 genes in Colombian families with suspicion of hereditary non-polyposis colorectal carcinoma (Lynch syndrome)

Gómez, Andrea; Salguero; García, Herbert; Aristizábal, Fabio; Gutiérrez, Óscar; Ángel, Luis Alberto; Padrón, Jorge; Martínez, Carlos; Martínez, Humberto; Malaver, Omar; Barvo, Rosa; Giraldo, Alejandro
2005-09-01

Resumen en español Introducción. El cáncer colorrectal es la segunda causa de morbilidad y mortalidad por cáncer en los países desarrollados. En Colombia es la quinta causa de muerte entre los diferentes cánceres. Cerca del 75% de éstos corresponde a cánceres esporádicos, alrededor del 25% son familiares, y son claramente hereditarios el 5%. De éstos, el más importantes es el cáncer colorrectal no polipósico hereditario o síndrome de Lynch. Objetivo. Analizar los dos genes más (mas) importantes involucrados en el síndrome de Lynch, el hMLH1 y el hMSH2. Materiales y métodos. En 17 familias colombianas que cumplían con los criterios de Ámsterdam II o las pautas de Bethesda, se analizaron por SSCP los 35 exones de estos dos genes y las variantes electroforéticas se secuenciaron. Resultados. Se detectaron 8 mutaciones de línea germinal en las familias analizadas, 7 en el gen hMLH1 y 1 en hMSH2, y se encontró una tasa de detección de mutaciones del 47%. Seis de las 8 mutaciones encontradas en este estudio han sido previamente reportadas en la literatura. Un cambio de una base en el sitio donador de empalme en el exón 9 del gen hMLH1 (G>A) (dos familias), un cambio A>G en el codón 755 del exón 17, y un cambio G>A en el exón 18. Se detectaron dos nuevas mutaciones, una en el exón 17, un cambio C>T en el codón 640, y una deleción de TG en el codón 184 del exón 3 del gen hMSH2. También se detectó en dos familias un polimorfismo del intrón 13 del hMLH1. Conclusión. Este es el primer estudio realizado en Colombia que detecta mutaciones en el síndrome de Lynch y pretende establecer un programa integral de manejo y prevención. Resumen en inglés Introduction. Colorectal cancer (CRC) is the second highest cause of cancer mortality in developed countries. In Colombia, CRC ranks fifth as a cause of cancer death. Approximately 75% of CRC appear to be spontaneous and 25% are familial, with 5% of the latter clearly hereditary. Of these, hereditary non-polyposis colorectal carcinoma (HNPCC)-or Lynch syndrome is the most important. Objective. Herein, the two most important genes involved in Lynch syndrome, the hMLH1 and (mas) hMSH2 were analyzed for presence of mutations. Materials and methods. Seventeen Colombian families that fulfilled the Amsterdam II criteria or Bethesda guidelines for Lynch syndrome were selected. The of 35 exons of hMLH1 and hMSH2 genes were screened by SSCP and those with electrophoretic variants were sequenced. Results. Eight germinal mutations were detected, corresponding to a 47% detection mutation rate. Six of the eight mutations have previously been reported. These consisted of the following mutations: a single base substitution at the donor splicing site of exon 9, a single base substitution (A>G) at codon 755 of the exon 17, and another single base substitution (G>A) at codon 681 of exon 18. The two novel mutations consisted of a single base substitution (C>T) at codon 640 of exon 17 of the hMLH1 gene and a two-nucleotide deletion (TG) at codon 184 of exon 3 of hMSH2 gene. In addition, two families were observed with a polymorphism in the intron 13 (G>A) nt 1558+14, of hMLH1 gene. Conclusions. This study represented the first survey for detecting mutations associated with Lynch syndrome in Colombia, and is intended to lead to the establishment of a management and prevention program.

Scientific Electronic Library Online (Spanish)

3

Efecto de la radiación gamma sobre la supervivencia y la inducción de la respuesta SOS en células de Escherichia coli deficientes en la reparación por escisión de nucleótidos y por recombinación/ Effect of gamma radiation on the survival and the induction of the SOS response in Eschericia coli cells deficient in the repair by excision of neuclotides and recombination

Almeida, Eliseo; Fuentes, Jorge L; Sánchez, Ángel; Carro, Sandra; Prieto, Enrique
2004-12-01

Resumen en español Se estudiaron los daños primarios producidos por la radiación gamma en el ADN de cepas de Escherichia coli portadoras de la fusión génica sulA::lacZ y de mutaciones en diferentes genes de reparación del ADN. Además, se determinó su radiosensibilidad. Las cepas con mutaciones en los genes recN y uvrA fueron más sensibles que la tipo salvaje. Esto concuerda con estudios previos donde se demostró que los genes rec y uvr participaban en la reparación del daño en el (mas) ADN producido por los rayos gamma. En las cepas mutantes se encontraron diferencias significativas en los niveles de expresión del gen sulA en relación con el tipo salvaje. Se discute la utilidad de las cepas estudiadas como biosensores de genotoxicidad así como en estudios de radioprotección. Resumen en inglés The primary damages produced by the gamma radiation in the DNA of Escherichia coli strains carriers of the sulA::lacZ genic fusion and of mutations in different DNA repair genes were studied. Its radiosensititvity was also determined. The strains with mutations in the recN and uvrA genes were more sensitive than the wild type. This agrees with previous studies where it was proved that the rec and uvr genes take part in the repair of the DNA damage produced by the gamma ra (mas) ys. In the mutant strains, there were found significant differences at the level of expression of the sulA gene in relation to the wild type. The usefulness of the strains studied as genotoxicity biosensors and in radioprotection studies was discussed.

Scientific Electronic Library Online (Spanish)

4

Análisis inmunohistoquimico y molecular de los genes de reparación en cáncer testicular/ Immunohistochemical and molecular analyis of mismatch repair genes in germ cell tumors

Velasco Palma, A.; Riquelme Sánchez, E.; Schulze Maroto, M.; Villarroel del Pino, L.; Leach, F.S.
2005-02-01

Resumen en español La corrección de los nucleótidos mal incorporados durante la replicación del ADN (sistema de reparación de genes) puede determinar un potencial biológico y clínico diferente en los tumores. En este trabajo investigamos la expresión inmunohistoquímica de los genes de reparación en cáncer de testículo en los distintos tipos histológicos, correlacionando el grado de expresión con la presencia de inestabilidad microsatélite y correlacionando ambas con la evoluci (mas) ón clínica. Pacientes y método: 118 casos de tumores testiculares fueron analizados molecularmente realizando inmunohistoquímica para hMLH1 y hMSH2. El análisis de inestabilidad microsatélite y LOH se realizó comparando ADN micro disecado de tejido tumoral y normal, el que fue amplificado mediante PCR con 10 marcadores preestablecidos. Resultados: El grado de expresión de hMSH2 se correlaciona con el estadio del tumor (p Resumen en inglés Correction of misincorporated nucleotides during DNA replication (mismatch repair) distinguishes histologically similar cancers with distinct biological and clinical behavior. We investigated expression of two mismatch repair genes in testis cancer to determine the expression pattern in histologically distinct subtypes, correlate expression with genetic instability and correlate expression and genetic instability with clinical outcome. Patients and methods: 118 cases of t (mas) estis cancer were analyzed. Immunohistochemical analysis of paraffin embedded specimens utilized monoclonal antibody for hMLH1 and hMSH2 mismatch repair proteins. Genetic instability was determined by comparing genomic DNA from microdissected matched normal and tumor cells. PCR amplification of 10 genetic markers assessed loss of heterozygosity and/or microsatellite instability. Results: hMSH2 staining was associated with pathologic stage (p

Scientific Electronic Library Online (Spanish)

5

Telomeros y reparación de daño genómico: su implicancia en patología humana/ Telomeres and genomic damage repair: Their implication in human pathology

Perez, M. del R.; Dubner, D.; Michelín, S.; Gisone, P.; Carosella, E.
2002-12-01

Resumen en español Los telómeros, complejos funcionales que protegen los extremos de los cromosomas eucariotes, participan en la regulación de la proliferación celular y pueden jugar un rol en la estabilización de ciertas regiones del genoma en respuesta a estrés genotóxico. Su relevancia en patología humana se ha puesto de manifiesto en numerosas enfermedades que comparten como rasgo común la inestabilidad genómica, en las que se comprobaron alteraciones del metabolismo teloméric (mas) o. Muchas de ellas se encuentran asociadas a hipersensibilidad a radiaciones ionizantes y susceptibilidad al cáncer. Además de las proteínas específicas que forman parte del complejo telomérico otras proteínas implicadas en la maquinaria de reparación del ADN tales como ATM, BRCA1, BRCA2 , sistema PARP/ tankirasa, complejo DNA-PK, y complejo RAD50- MRE11-NBS1, se encuentran en estrecha asociación con el mismo. Esto sugiere que el telómero secuestra proteínas de reparación para el mantenimiento de su propia estructura, las que podrían asimismo ser liberadas hacia sitios de daño en el ADN genómico. Esta comunicación describe los aspectos más relevantes de la estructura y función de los telómeros y su vinculación con los procesos de recombinación homóloga, recombinación no homóloga (NHEJ), sistema V(D)J y sistemas de reparación de apareamientos erróneos (MMR), considerando ciertas condiciones patológicas que exhiben alteraciones en algunos estos mecanismos. Se aborda en forma particular la respuesta celular a las radiaciones ionizantes y su relación con el metabolismo telomérico como un modelo de estudio de genotoxicidad. Resumen en inglés Telomeres, functional complexes that protect eukaryotic chromosome ends, participate in the regulation of cell proliferation and could play a role in the stabilization of genomic regions in response to genotoxic stress. Their significance in human pathology becomes evident in several diseases sharing genomic instability as a common trait, in which alterations of the telomere metabolism have been demonstrated. Many of them are also associated with hypersensitivity to ioniz (mas) ing radiation and cancer susceptibility. Besides the specific proteins belonging to the telomeric complex, other proteins involved in the DNA repair machinery, such as ATM, BRCA1, BRCA2, PARP/ tankyrase system, DNA-PK and RAD50-MRE11-NBS1 complexes, are closely related with the telomere. This suggests that the telomere sequesters DNA repair proteins for its own structure maintenance, which could also be released toward damaged sites in the genomic DNA. This communication describes essential aspects of telomere structure and function and their links with homologous recombination, non-homologous end-joining (NHEJ), V(D)J system and mismatch-repair (MMR). Several pathological conditions exhibiting alterations in some of these mechanisms are also considered. The cell response to ionizing radiation and its relationship with the telomeric metabolism is particularly taken into account as a model for studying genotoxicity.

Scientific Electronic Library Online (Spanish)

6

La mutación adaptativa: Polémicas y mecanismos

Nagel, Rosa
2007-12-01

Resumen en español La variabilidad genómica, que es una propiedad intrínseca de los organismos, juega un rol esencial en el proceso evolutivo. Se analizan algunos de los procesos generadores de variabilidad genómica, con particular énfasis en el mecanismo de la mutagénesis que tiene lugar en las bacterias en las condiciones de estrés de fase estacionaria. Este proceso requiere la presencia de roturas en el ADN, la participación de proteínas de recombinación y reparación del ADN y de polimerasas específicas, y la inducción de respuestas celulares al estrés. Resumen en inglés Genomic variation plays an essential role in evolution. Some of the processes underlying genomic variability are being analyzed, with particular emphasis on the mechanism of mutagenesis taking place with bacteria under stationary-phase stress conditions. This process involves the presence of DNA nicks or breaks, the participation of recombination-repair proteins and specific polymerases, and the induction of cellular stress responses.

Scientific Electronic Library Online (Spanish)

7

Cáncer de mama familiar, BRCA1 positivo/ Familiar breast cancer, positive BRCA1

FIGUEROA G, LUIS; BARGALLO R, ENRIQUE; CASTORENA R, GERARDO; VALANCI A, SOFÍA
2009-12-01

Resumen en español Paciente de género femenino de 51 años que en una revisión de rutina se observó lesión sospechosa de mama derecha, BIRADS IVa. Patología reportó cáncer ductal infiltrante moderadamente diferenciado con dos focos de carcinoma invasor separados de 2 y 1 mm, receptores de estrógeno y progesterona positivos. El cáncer de mama familiar abarca entre el 5% al 10% de cáncer de mama de la población en general. Los genes involucrados en este padecimiento son: BRCA1 en 2 (mas) 0%, BRCA 2 en 20%, CHEK2 en 5%, TP 53 en 1%, sin embargo, en más del 50% de los casos se desconoce en gen asociado. El BRCA1 es un gen localizado en el cromosoma 17q21, supresor de tumor, involucrado en la regulación del ciclo celular, reparación del ADN dañado, mantenimiento de la estabilidad genómica y regulación de la transcripción. Existen indicaciones precisas para la búsqueda intencionada del gen BRCA en pacientes con historia familiar o personal de cáncer de mama y ovario Resumen en inglés 51 year old female found on check up a suspicious lesion in right breast, BIRADS IVa. Pathology reported a ductal infiltrative moderately differentiated cancer with two separate carcinomas of 2 and 1 mm each, progesterone and estrogen receptors. Familiar breast cancer is calculated to be about 5-10% of all breast cancers. The genes involved are: BCRA1 in 20%, BRCA2 in 20%, CHEK2 in 5%, TP 53 in 1%, although more than 50% of cases are not associated with a gen. BRCA1 is a (mas) gene in chromosome 17q21, tumor suppressor, involved in the regulation of the cellular cycle, repair of damaged DNA, maintenance of genomic stability and regulation of transcription. Specific indications are in use for BCRA gene scouting in women with family or personal history of breast or ovary cancer

Scientific Electronic Library Online (Spanish)

8

Tinidazol: una droga antimicrobiana con actividad genotóxica

Rodríguez Ferreiro, Gisell; Cancino Badías, Lourdes; Prieto González, Elio; Espinosa Aguirre, Javier
2001-03-01

Resumen en español La reducción del grupo nitro presente en varios medicamentos, pesticidas y materiales de uso diario, produce especies reactivas del oxígeno capaces de interactuar con el ADN. El tinidazol, una droga antimicrobiana de la familia de los 5 nitroimidazoles, fue evaluada por el ensayo cometa. Se estudió la capacidad de la droga para inducir roturas de simple cadena y sitios sensibles al álcali, expresado como el porcentaje de células dañadas y el porcentaje de células e (mas) n cada nivel de daño. En el ensayo in vitro a concentraciones de 100, 250 y 500 mg/mL se encontró inducción de roturas en los cromosomas de leucocitos de ratón a los 30 min de exposición, esto describió una relación dosis respuesta. La importancia de la reducción del grupo nitro, mediada por la acción de nitrorreductasas microsomales hepáticas, para la actividad mutagénica de los nitroimidazoles, ha sido estudiada. Sin embargo, estos resultados revelaron que el tinidazol no necesitaba ser metabolizado para inducir el daño. A los 30 min de reparación el daño en los leucocitos se mantuvo, a los 60 min solamente el daño producido con la concentración de 500 mg/mL de tinidazol había sido reparado. A concentraciones mayores se disparan diferentes mecanismos de reparación para no comprometer la viabilidad celular. Estos mecanismos pueden ser responsables de estos hallazgos, se reparan las roturas aunque se comprometa la fidelidad de la secuencia del ADN. In vivo se pudo observar que una dosis de 100 mg/kg de peso era capaz de inducir daño en el ADN de los leucocitos de ratón. Este efecto fue observado a las 24 y 48 h después del tratamiento con una dosis 3 veces superior a la dosis terapéutica (2 g/d). El mecanismo propuesto para explicar el efecto clastogénico de los 5 nitroimidazoles está relacionado con la formación de un anión nitro, que se reoxida y genera especies reactivas del oxígeno Resumen en inglés The reduction of the mitro group existing in various drugs, pesticides and materials of daily use gives rise to reactive oxygen species capable of interacting with DNA. Tinidazole, an antimicrobial drug of the family of the 5 nitroimidazols was tested using a comet assay. The capacity of this drug to induce single chain breaks and alkali-sensitive sites expressed as the percentages of damaged cells and cells at each level of damage was studied. The in vitro assay at conce (mas) ntrations of 100, 250 and 500 µ/mL showed the induction of breaks in rat leukocyte chromosomes after 30 minutes of exposure. This indicated a dosage-response ratio. The importance of the hepatic microsomal nitroreductase-mediated nitro group reduction for the mutagenic activity of nitroimidazols has been studied. However, these results revealed that tinidazole did not require to be metabolized to induce damage. After 30 minutes of repair, the leukocyte damage persisted, and 60 minutes after only the damage caused by the 500 µ/ml tinidazole concentration had been repaired. At higher concentrations, different repair mechanisms are triggered so as not to put cell viability in jeopardy. These mechanisms may be responsible for these findings; the breaks are repaired even if the fidelity of DNA sequence is endangered. It can be observed in the in vivo/assay that a dose of 100 mg/kg weight can induce damage in mouse leukocyte DNA. This effect was seen 24 and 48 hrs after the treatment with a dose that triplicated the therapeutical dose (2g/day). The suggested mechanism for explaining the clastogenic effect of the five nitrimidazols is related with the formation of a nitro annion which re-oxidizes an generates reactive oxygen species

Scientific Electronic Library Online (Spanish)

9

Exploración del efecto protector frente a radicales libres de derivados de la uva (Vitis vinifera L. Cv. Tannat) en Saccharomyces cerevisiae/ Analysis of a putative protection against free radicals by grape derivatives (Vitis vinifera L. Cv. Tannat) in Saccharomyces cerevisiae

Bracesco, N.; Salvo, V. A.; Rocha, S.; Dell, M.; Carrau, F.; Nunes, E.
2007-03-01

Resumen en español Se exploró un posible efecto protector del genoma por parte de un derivado de la uva (vino Tannat). Se utilizaron poblaciones celulares haploides y diploides de Saccharomyces cerevisiae como modelo eucariota. Muestras celulares se expusieron a H2O2 en medio nutriente. El ADN se analizó por densitometría láser, luego de su aislamiento y separación por electroforesis con campos pulsados. Se aplicó la distribución de Poisson para la determinación de roturas dobles. E (mas) l número de roturas dobles del ADN y la frecuencia mutagénica aumentaron en función de la dosis de H2O2, disminuyendo la probabilidad de sobrevida. La combinación de H2O2 con vino Tannat aumentó significa-tivamente la probabilidad de sobrevida y disminuyó el número de roturas dobles. No se observó efecto mutagénico por el vino Tannat. Estos efectos pudieron simularse utilizando altas concentraciones de α-tocoferol. Los resultados indican que un derivado de Vitis vinifera puede, en ciertas condiciones, disminuir las dobles roturas de ADN producidas por el H2O2 e incrementar las probabilidades de sobrevida celular. Los blancos involucrados podrían ser, entre otros, componentes intracelulares de las cascadas redox y/o enzimas de reparación del ADN. Resumen en inglés The aim of this work was to analyse a possible genome protection provided by a grape derivative (Tannat wine) in yeast cell populations exposed to H2O2. Haploid and diploid strains of Saccharomyces cerevisiae were used as eukaryotic model. Cell samples were exposed to H2O2 in a nutrient medium. Chromosomal DNA was analysed after isolation and separation by pulsed field electrophoresis. Double strand breaks were determined by laser densitometry and application of Poisson d (mas) istribution. Both haploid and diploid cells showed H2O2 dose dependent DNA fractionation, as well as an increase of lethal -and mutation- events. Upon combination of the Tannat wine and H2O2 a significant decrease of double strand breaks was observed, in association with an increase in surviving fractions. No mutagenic effect was observed after wine exposure. Part of the observations regarding protective wine effect were simulated by exposure to high concentrations of α-tocopherol. Present results indicate that a grape derivative could act as a genome protector increasing cell survival probabilities. Among others, the involved molecular targets could be components of transduction redox cascades as well as DNA repair enzymes.

Scientific Electronic Library Online (Spanish)

10

Ética científica de la terapia génica de individuos: Urgencia de la Cirugía Génica del ADN/ Scientific ethics of gene therapy for individuals: The urgency for DNA gene surgery

Valenzuela, Carlos Y
2003-10-01

Resumen en inglés Gene therapy for individuals is mainly directed to somatic or germ cells. The present technology aims to insert a DNA segment in the recipient cells. This therapy is useful in Mendelian recessive diseases. There is an ethical moratorium to perform insertion gene therapy in germ cells, because this procedure increases the human genome. Somatic cell gene therapy cures individuals but increases the gene frequency of genetic diseases in the population. This occurs because the (mas) descendants of the cured patient should carry his or her «ill» genes. We denote by «DNA gene surgery» the procedure that replaces «ill» nucleotide(s) by healthy one(s) conserving the genome size and the gene context of expression and regulation. Several procedures for gene surgery have been applied to cells and animals. Those based on DNA repair as Chimeric RNA/DNA, one stranded oligonucleotides and tristranded DNA. Those based on DNA recombination with oligo-DNA or one stranded DNA, and transposable DNA segments. Gene surgery can be applied to germ cell gene therapy without ethical contraindications. It can cure Mendelian dominant diseases and it can be applied to heterozygotes. It preserves the regulation and expression gene context. If a technical safe procedure is available, the entire mankind could be treated and cured of all the Mendelian diseases, in one generation. Susceptibilities for all diseases could also be treated. The moratorium for research on germ cell gene therapy by gene surgery should be interrupted. Safe gene surgery is a moral imperative for gene therapy of patients and their descendants, for the treatment of dominant genetic diseases and for heterozygous carriers of recessive disorders (Rev Méd Chile 2003; 131: 1208-14)

Scientific Electronic Library Online (Spanish)

11

p53-Independent checkpoint controls in a plant cell model

Pelayo, Helvia R.; Pincheira, Juana; Giménez-Abián, Juan F.; Clarke, Duncan J.; Torre, Consuelo de la
2004-09-01

Digital.CSIC (Spain)

12

Therapeutic effect of a poly(ADP-ribose) polymerase-1 inhibitor on experimental arthritis by downregulating inflammation and Th1 response

Elena Gonzalez-Rey; Ruben Martínez-Romero; Francisco O'Valle; Rocío Aguilar-Quesada; Carmen Conde; Mario Delgado

6 pages, 3 figures.-- PMID: 17971849 [PubMed].-- PMCID: PMC2034533. | Poly(ADP-ribose) polymerase-1 (PARP-1) synthesizes and transfers ADP ribose polymers to target proteins, and regulates DNA repair and genomic integrity maintenance. PARP-1 also plays a crucial role in the progression of the inflam...

DRIVER (Spanish)

13

Therapeutic effect of a poly(ADP-ribose) polymerase-1 inhibitor on experimental arthritis by downregulating inflammation and Th1 response

González-Rey, Elena; Martínez-Romero, Rubén; O'Valle, Francisco; Aguilar-Quesada, Rocío; Conde, Carmen; Delgado, Mario; Oliver, F. Javier
2007-10-31

Digital.CSIC (Spain)

15

The G2 checkpoint activated by DNA damage does not prevent genome instability in plant cells

Carballo, Jesús A.; Pincheira, Juana; Torre, Consuelo de la
2006-04-01

Digital.CSIC (Spain)

16

The Drosophila spn-D gene encodes a RAD51C-like protein that is required exclusively during meiosis

Abdu, Uri; González-Reyes, Acaimo; Ghabrial, Amin; Schüpbach, Trudi

Sequence data from this article have been deposited with the Gen-Bank data libraries under accession no. AY257540. | In Drosophila, mutations in double-strand DNA break (DSB) repair enzymes, such as spn-B, activate a meiotic checkpoint leading to dorsal-ventral patterning defects in the egg and an a...

DRIVER (Spanish)

17

The Drosophila spn-D gene encodes a RAD51C-like protein that is required exclusively during meiosis

Abdu, Uri; González-Reyes, Acaimo; Ghabrial, Amin; Schüpbach, Trudi
2003-09-01

Digital.CSIC (Spain)

18

Síndrome de Lynch: Caracterización genético clínica. Caso clínico/ Hereditary non-polyposis colorectal cancer: Report of four siblings

Zárate, Alejandro; Álvarez, Karin; Wielandt, Ana María; Hevia, Montserrat; De la Fuente, Marjorie; Carvallo, Pilar; López-Köstner, Francisco
2008-06-01

Resumen en inglés Hereditary non-polyposis colorectal cancer (HNPCC) or Lynch Syndrome is an autosomic dominant syndrome involving 596-1096 of colorectal cancer patients. Mutations in MLH1 and MSH2 genes account for most cases. These two genes particípate in the DNA mismatch repair pathway. Therefore mutation carriers show microsatellite instability (MSI) in tumors. This syndrome is characterized by the early development of colorectal cancer (before 50 years) and an increased incidence of (mas) cancer in other organs. We report four siblings from a family diagnosed with HNPCC. All of them were subjected to colonic surgery for colorectal cancer Moreover, one patient developed an ampulloma after her colon surgery. The molecular-genetic analysis revealed three brothers with microsatellite instability in the tumor tissue, the absence of the MLH1 protein, and the presence of a germ Une mutation localized in introm 15 ofthe MLH1 gene

Scientific Electronic Library Online (Spanish)

19

Síndrome de Cockayne: Informe de un caso. Revisión de la literatura/ Cockayne’s Syndrome: A case report. Literature review

Arenas Sordo, María de la Luz; Hernández Zamora, Edgar; Montoya Pérez, Luis Alberto; Aldape Barrios, Beatriz Catalina
2006-06-01

Resumen en español El Síndrome de Cockayne (CS) es un desorden genético con un patrón de herencia autosómico recesivo que fue descrito por primera vez en 1936 por Cockayne. Los pacientes con este síndrome presentan detención del crecimiento, talla baja, envejecimiento prematuro, anormalidades neurológicas, fotosensibilidad, retraso en la erupción de los dientes primarios, ausencia congénita de dientes permanentes, macrodoncia parcial, atrofia de los procesos alveolares y caries den (mas) tal. Puede ser causado por mutación en dos genes, el CKN1 (ERCC8) y el ERCC6, localizados en los cromosomas 5 y 10 respectivamente; originando dos tipos: CS-A que tienen mutación en ERCC8 y CS-B con mutación en ERCC6, este último provoca sensibilidad a la luz ultravioleta, secundaria a una deficiencia en la reparación de DNA.También se ha asociado el síndrome a mutaciones de los genes XPB, XPD y XPG. En el presente reporte se informa de un paciente de 9 años con cuatro meses de edad. En la exploración física se registró talla de 94 cm, peso de 8.6 kg y perímetro cefálico de 42 cm. TA 120/80. Hábito caquéctico, problemas posturales con encorvamiento, así como microcefalia, cara ovalada, ojos hundidos, nariz delgada y afilada, falta de grasa en la cara, más notorio en el tercio medio y orejas grandes que le confieren una apariencia de "pajarito". Se observa marcada fotosensibilidad en toda la piel expuesta al sol. Presenta retraso psicomotor y mental. Intrabucalmente se aprecia higiene deficiente, gingivitis, caries cervical, hipoplasia del esmalte, mala posición dentaria de los incisivos laterales superiores e inferiores, y macrodoncia de los dientes centrales superiores, el izquierdo presenta una lesión por caries. Radiográficamente se observa ausencia congénita de los dientes 14, 23, 24 e hipoplasia mandibular. El objetivo de este trabajo es dar a conocer a la comunidad odontológica las características del síndrome de Cockayne a través de un caso clínico. Resumen en inglés Cockayne’s syndrome is a genetic disorder with a recessive autosomal inheritance, described first by Cockayne in 1936. Patients with this syndrome present failure to thrive, short stature, premature aging, neurological alterations, photosensitivity, delayed eruption of the primary teeth, congenitally absent of some permanent teeth, partial macrodontia, atrophy of the alveolar process and caries. It could be caused by two gene mutations, CNK1 (ERCC8) and ERCC6, located on (mas) the 5 and 10 chromosomes respectively, causing two variations of Cockayne’s syndrome, CS-A, secondary to a ERCC8 mutation and CS-B with ERCC6 mutation, the last one causes hypersensitivity to the ultraviolet light secondary to a DNA repair defect. The syndrome is also associated with mutations of the XPB, XPD and XPG genes. In this report we present a 9 year and 4 month old patient. He had a height of 94 cm, weight of 8.6 Kg, head circumference of 42 cm. and blood pressure of 120/80. Cachectic habitus, kyphosis, microcephaly, oval face, sunken eyes, a thin and beaklike nose, lack of subcutaneous facial fat (especially in the middle of the face), and large ears give the patient a birdlike appearance. It is notorious the photosensitivity in all the sun-exposed skin. The patient also displays delayed psychomotor skills and mental retardation. In the oral cavity we found deficient hygiene, gingivitis, cervical caries, enamel hipoplasia, abnormal position of the upper and inferior lateral incisors, macrodontia of the upper central teeth, the left one presented a caries. In the x-ray we observed congenital absence of 14, 23 and 24 teeth and mandibular hipoplasia. The aim of this review is to show the dentistry community the characteristics of the Cockayne’s syndrome by means of a clinical case.

Scientific Electronic Library Online (Spanish)

20

Sequential Loading of Cohesin Subunits during the First Meiotic Prophase of Grasshoppers

Valdeolmillos, Ana M.; Viera, Alberto; Page, Jesús; Prieto, Ignacio; Santos, Juan L.; Parra, María Teresa; Heck, Margarete M. S.; Martínez-Alonso, Carlos; Barbero, José L.; Suja, José A.; Rufas, Julio S.
2007-02-23

Digital.CSIC (Spain)

21

Securin Is a Target of the UV Response Pathway in Mammalian Cells

Romero, Francisco; Gil-Bernabé, Ana M.; Sáez, Carmen; Japón, Miguel A.; Pintor-Toro, José A.; Tortolero, María

All eukaryotic cells possess elaborate mechanisms to protect genome integrity and ensure survival after DNAdamage, ceasing proliferation and granting time for DNA repair. Securin is an inhibitory protein that is boundto a protease called Separase to inhibit sister chromatid separation until the on...

DRIVER (Spanish)

22

Securin Is a Target of the UV Response Pathway in Mammalian Cells

Romero, Francisco; Gil-Bernabé, Ana M.; Sáez, Carmen; Japón, Miguel A.; Pintor-Toro, José A.; Tortolero, María
2004-01-01

Digital.CSIC (Spain)

23

SMC proteins, new players in the maintenance of genomic stability

Cortés-Ledesma, Felipe; Piccoli, Giaccomo de; Haber, James E.; Aragón, Luis; Aguilera, Andrés
2007-04-15

Digital.CSIC (Spain)

24

Roles of nibrin and ATM/ATR kinases on the G2 checkpoint under endogenous or radio-induced DNA damage

Marcelain, Katherine; Torre, Consuelo de la; González, Patricio; Pincheira, Juana

Checkpoint response to DNA damage involves the activation of DNA repair and G2 lengthening subpathways. The roles of nibrin (NBS1) and the ATM/ATR kinases in the G2 DNA damage checkpoint, evoked by endogenous and radio-induced DNA damage, were analyzed in control, A-T and NBS lymphoblast cell lines....

DRIVER (Spanish)

25

Roles of nibrin and ATM/ATR kinases on the G2 checkpoint under endogenous or radio-induced DNA damage

Marcelain, Katherine; Torre, Consuelo de la; González, Patricio; Pincheira, Juana
2005-07-01

Digital.CSIC (Spain)

26

Protein-protein interaction antagonists as novel inhibitors of non-canonical polyubiquitylation

Scheper, Johanna; Guerra-Rebollo, Marta; Sanclimens Pérez de Rozas, Gloria; Masip, Isabel; González-Ruiz, Domingo; Rubio, Nuria; Crosas, Bernat; Meca-Cortés, Óscar; Loukili, Noureddine; Plans, Vanessa; Morreale de León, Antonio; Blanco Fernández, Jerónimo; Ortiz, Ángel R.; Messeguer Peypoch, Àngel; Thomson, Timothy M.
2010-06-30

Digital.CSIC (Spain)

27

Protein p56 from the Bacillus subtilis phage phi 29 inhibits DNA-binding ability of uracil-DNA glycosylase

Serrano-Heras, Gemma; Ruiz-Masó, José A.; del Solar, Gloria; Espinosa, Manuel; Bravo, Alicia; Salas, Margarita

Protein p56 (56 amino acids) from the Bacillus subtilis phage phi 29 inactivates the host uracil-DNA glycosylase (UDG), an enzyme involved in the base excision repair pathway. At present, p56 is the only known example of a UDG inhibitor encoded by a non-uracil containing viral DNA. Using analytical ...

DRIVER (Spanish)

28

Protein p56 from the Bacillus subtilis phage phi 29 inhibits DNA-binding ability of uracil-DNA glycosylase

Serrano-Heras, Gemma; Ruiz-Masó, José A.; Solar, Gloria del; Espinosa, Manuel; Bravo, Alicia; Salas, Margarita
2007-08-13

Digital.CSIC (Spain)

30

Overexpression of human DNA polymerase µ (Pol µ) in a Burkitt's lymphoma cell line affects the somatic hypermutation rate

Ruiz, José F.; Lucas, Daniel; García-Palomero, Esther; Saez, Ana I.; González, Manuel A.; Piris, Miguel A.; Bernad, Antonio; Blanco, Luis
2004-11-01

Digital.CSIC (Spain)

31

Nuevas perspectivas en el tratamiento del cáncer de pulmón no microcítico: farmacogenómica/ New prospects in non-small cell lung cancer treatment: pharmacogenomics

Cobo Dols, M.; Gil Calle, S.; Villar Chamorro, E.; Alés Díaz, I.; Montesa Pino, A.; Alcaide García, J.; Gutiérrez Calderón, V.; Carabante Ocón, F.; Bretón García, J. J.; Benavides Orgaz, M.
2006-02-01

Resumen en español La estrategia de tratamiento más utilizada en el cáncer de pulmón no microcítico (CPNM) avanzado es la quimioterapia, concretamente la combinación de dos drogas, principalmente cisplatino con gemcitabina, vinorelbina, taxanos, irinotecan. En el pasado se han hecho intentos en vano de revertir la resistencia a la quimioterapia. La supervivencia en este estadio no suele superar los 8-10 meses con el tratamiento convencional. En el presente, intentos para superar estos (mas) resultados se focalizan en la farmacogenómica, con el objetivo de individualizar la quimioterapia basado en aspectos de biología molecular, como los polimorfismos, mutaciones genéticas, y sobreexpresión de genes que pueden funcionar como dianas de los fármacos. La evidencia indica que algunos marcadores genéticos pueden ser predictivos de resistencia a la quimioterapia. Uno de los objetivos en investigación translacional es investigar la aplicación clínica de los sistemas de reparación del DNA. Algunos genes como ERCC1, XPD polymorphisms. RRM1, BCRA1, etc, se relacionan con resistencia a cisplatino y otras drogas. Resumen en inglés The most commonly used chemotherapy strategy in advanced non-small cell lung cancer (NSCLC) today is the combination of two drugs, mainly cisplatin with another drug (gemcitabine, vinorelbine, taxanes, irinotecan). In the last decade attempts have been made to overcome chemotherapy resistance without benefit in outcome. There is a "plateau" in the results which seems unable to progress beyond the frontier of 8-10 months of median survival. At present, research in cancer s (mas) urvival is focused on translational pharmacogenomics, with the goal of providing individualized CT based on different genetic traits, such a polymorphisms, gen mutation and overexpresion of drug target gene transcripts, and several molecular assays can been used to tailor chemotherapy in the care of lung cancer patients. Accumulated evidence indicates that many genetic markers are related to chemotherapy resistance. One of the most important goals in translational research is to investigate the clinical use of the DNA repair pathways. Several genes such as ERCC1, XPD polymorphisms. RRM1, BCRA1, etc are related to cisplatin and other drugs resistance.

Scientific Electronic Library Online (Spanish)

32

Nucleoporins Prevent DNA Damage Accumulation by Modulating Ulp1-dependent Sumoylation Processes

Palancade, Benoit; Xianpeng, Liu; García Rubio, María; Aguilera, Andrés; Xiaolan, Zhao; Doye, Valérie

Final full-text version of the paper available at: http://dx.doi.org/10.1091/mbc.E07-02-0123. Copyright © 2007 by The American Society for Cell Biology.-- PMCID: PMC1949349.-- Supplementary material available at: http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1949349&blobname=mbc_E07-02-0123_...

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Nucleoporins Prevent DNA Damage Accumulation by Modulating Ulp1-dependent Sumoylation Processes

Palancade, Benoit; Xianpeng, Liu; García-Rubio, María L.; Aguilera, Andrés; Xiaolan, Zhao; Doye, Valérie
2007-08-01

Digital.CSIC (Spain)

34

Mutación fundadora en una familia argentina con cáncer colorrectal hereditario/ Detection of a founder mutation in an Argentine family with hereditary non polyposis colorectal cancer

Gómez, Laura; Adi, José; Ibarra, Jorge; Roqué, María
2010-02-01

Resumen en español El cáncer colorrectal hereditario no poliposo (CCHNP) se relaciona con mutaciones en los genes reparadores de ADN (MLH1, MSH2 y MSH6). La mayoría de estas alteraciones son familia-específicas y su detección suele requerir la secuenciación completa de los genes relacionados. Se detectó una mutación puntual (2269-2270insT) en el último codón del gen MLH1 en familias de un área del norte de Italia (Reggio Emilia) y su origen se considera debido a un efecto fundador (mas) . En este trabajo presentamos una familia mendocina con CCHNP portadora de la misma mutación, cuyos ancestros eran oriundos de Reggio Emilia. Para la detección de la mutación se diseñó una estrategia basada en PCR y posterior corte enzimático. La mutación fue hallada en tres integrantes de la familia estudiada, dos de los cuales no presentaban sintomatología clínica. Estos pacientes fueron seguidos preventivamente mediante colonoscopias. La metodología utilizada en nuestro laboratorio fue específica y sensible para la detección de una mutación previamente registrada y permitió realizar el diagnóstico genético molecular en el país, evitando el envío de muestras al extranjero. Es de importancia destacar que el diagnóstico genético pre-sintomático de cáncer hereditario, enfocado desde un grupo multidisciplinario de profesionales, permite un mejor seguimiento y apoyo a las familias afectadas. Resumen en inglés Hereditary non polyposis colorectal cancer (HNPCC) has been related to mutations in the DNA mismatch repair genes (MLH1, MSH2 y MSH6). Mutation detection analysis requires the complete sequencing of these genes, given the high frequency of family-specific alterations. A point mutation (2269- 2270insT) in the last codon of the MLH1 gene has been detected in families from a northern region of Italy (Reggio Emilia).Given that this alteration was registered only in people fro (mas) m this region, it has been considered a founder mutation. In this work, we present an Argentine HNPCC family whose ancestors were natives from the Reggio Emilia, Italy, and who were carriers for this mutation. In order to detect the genetic alteration, a PCR was developed followed by a restriction enzyme incubation assay. The mutation was detected in 3 family members, two of them without clinical symptoms. The PCR/restriction enzyme methodology has been sensitive and specific for the detection of this mutation. It has allowed the performance of a pre-symptomatic genetic diagnosis in the Argentine HNPCC family, avoiding sending samples abroad. It is worth mentioning that pre-symptomatic diagnosis of hereditary cancers allows enhanced surveillance and support for the affected families when it is performed by a multidisciplinary group.

Scientific Electronic Library Online (Spanish)

35

Molecular Characterization of Spontaneous Mesenchymal Stem Cell Transformation

Rubio, Daniel; García, Silvia; Paz, María F.; Cueva, Teresa de la; López-Fernández, Luis A.; Lloyd, Alison C.; García-Castro, Javier; Bernad, Antonio
2008-01-02

Digital.CSIC (Spain)

36

Microbial Cretaceous park: biodiversity of microbial fossils entrapped in amber

Martín González, Ana; Wierzchos, Jacek; Gutiérrez, Juan Carlos; Alonso, Jesús; Ascaso, Carmen
2009-01-01

Digital.CSIC (Spain)

37

Merotelic attachments and non-homologous end joining are the basis of chromosomal instability

Alonso Guerrero, Astrid; Martínez-Alonso, Carlos; van Wely, Karel H.M.
2010-05-17

Digital.CSIC (Spain)

38

Mechanism of G2-Repair to preserve chromosome integrity and its inhibition by caffeine

López-Sáez, J. F.; González-Fernández, A.; Hernández, P.; Zamorano, E.; Navarrete, M. H.

[EN] In proliferating eukaryotic cells, there occurs a striking chromosome repair mechanism, wich operates during G2 and prophase of the division cycle. The main task of this repair mechanism could by the removal of DNA lesions able to give rise chromosomal aberrations during chromatin condensation ...

DRIVER (Spanish)

39

Mechanism of G2-Repair to preserve chromosome integrity and its inhibition by caffeine

López-Sáez, J. F.; González-Fernández, A.; Hernández, P.; Zamorano, E.; Navarrete, M. H.
1988-01-01

Digital.CSIC (Spain)

40

Lack of sugar discrimination by human Pol µ requires a single glycine residue

Ruiz, José F.; Juárez, Raquel; García-Díaz, Miguel; Terrados, Gloria; Picher, Angel J.; González-Barrera, Sergio

DNA polymerase mu (Pol µ) is a novel family X DNA polymerase that has been suggested to play a role in micro-homology mediated joining and repair of double strand breaks. We show here that human Pol µ is not able to discriminate against the 2'-OH group of the sugar moiety. It inserts rNTPs with an e...

DRIVER (Spanish)

41

Lack of sugar discrimination by human Pol µ requires a single glycine residue

Ruiz, José F.; Juárez, Raquel; García-Díaz, Miguel; Terrados, Gloria; Picher, Ángel J.; González-Barrera, Sergio; Fernández de Henestrosa, Antonio; Blanco, Luis
2003-01-01

Digital.CSIC (Spain)

42

Isolation and characterization of casein kinase I from Dictyostelium discoideum

Moreno-Bueno, Gema; Calés Bourdet, Carmela; Behrens, M. Margarita; Fernández-Renart, Margarita
2000-07-15

Digital.CSIC (Spain)

43

Interacciones de las radiaciones electromagnéticas y especies reactivas del oxígeno sobre la piel/ Interactions of electromagnetic radiations and reactive oxygen species on skin

Ferramola de Sancovich, A M; Sancovich, H A
2006-06-01

Resumen en español La energía radiante abarca todo el espectro electromagnético y proviene de la fusión en el sol, de 4 núcleos de hidrógeno en uno de helio. Las radiaciones electromagnéticas tienen características de ondas, con la velocidad de la luz (c) y difieren en sus longitudes de ondas (λ). La energía lumínica es transmitida en unidades individuales o fotones: E = h c/λ así, los fotones de menores λs son los de mayor energía. Las radiaciones ultravioletas (U (mas) V) (λs de 200 - 400 nm) pueden dividirse: UVA (λs 315 - 400 nm); UVB (λs 280 - 315 nm) y UVC (λs Resumen en inglés The energy of electromagnetic radiation is derived from the fusion in the sun of four hydrogen nuclei to form a helium nucleus. The sun radiates energy representing the entire electromagnetic spectrum. Light is a form of electromagnetic radiation. All electromagnetic radiation has wave characteristics and travels at the same speed (c: speed of light). But radiations differ in wavelength (λ). Light energy is transmitted not in a continuum stream but only in individual (mas) units or photons: E = h c/λ. Short wave light is more energetic than photons of light of longer wavelength. Ultraviolet radiations (UV) (λs 200 - 400 nm) can be classified in UVA (λs 315 - 400 nm.); UVB (λs 280 - 315 nm) and UVC (λs

Scientific Electronic Library Online (Spanish)

44

Identification of Differential Protein Expression Associated with Development of Unstable Human Carotid Plaques

Slevin, Mark; Elasbali, Abdul Baset; Turu, Marta M.; Krupinski, Jerzy; Badimón, Lina; Gaffney, John
2006-03-01

Digital.CSIC (Spain)

45

Human securin, hPTTG, is associated with Ku heterodimer, the regulatory subunit of the DNA-dependent protein kinase

Romero, Francisco; Multon, Marie-Christine; Ramos-Morales, Francisco; Domínguez, África; Bernal, Juan A.; Pintor-Toro, José A.; Tortolero, María
2001-01-01

Digital.CSIC (Spain)

46

How to exchange your partner. Workshop on Recombination Mechanisms and the Maintenance of Genomic Stability

Aguilera, Andrés; Boulton, Simon J.

Presented at the European Molecular Biology Organization workshop, Seillac, France, 15-19 May 2006, organized by S. West, A. Nicolas and M. Foiani.-- Final full-text version of the paper available at: http://dx.doi.org/10.1038/sj.embor.7400872 | The accurate repair of DNA double-strand breaks (DSBs)...

DRIVER (Spanish)

48

Growth hormone protects against radiotherapy-induced cell death

Madrid, Olga; Varea, Silvia; Sánchez Pérez, Isabel; Gómez-García, Lourdes; Miguel, Enrique de; Gómez de Segura, Ignacio A.; Perona Abellán, Rosario
2000-10-01

Digital.CSIC (Spain)

49

Genotoxic effects in swimmers exposed to disinfection by-products in indoor swimming pools

Kogevinas, Manolis; Villanueva, Cristina M.; Font-Ribera, Laia; Liviac, Danae; Bustamante, Mariona; Espinoza, Felicidad; Nieuwenhuijsen, Mark J.; Espinosa, Aina; Fernández, Pilar; DeMarini, David M.; Grimalt, Joan O.; Grummt, Tamara; Marcos, Ricard
2010-09-12

Digital.CSIC (Spain)

50

Genomewide expression profiling of cryptolepine-induced toxicity in Saccharomyces cerevisiae

Rojas, Marta; Wright, Colin W.; Piña, Benjamín; Portugal, José
2008-08-18

Digital.CSIC (Spain)

51

Genome-wide analysis of factors affecting transcription elongation and DNA repair: a new role for PAF and Ccr4-not in transcription-coupled repair

Gaillard, Hélène; Tous, Cristina; Botet, Javier; González-Aguilera, Cristina; Quintero, María José; Viladevall, Laia

15 pages, 9 figures.-- PMID: 19197357 [PubMed].-- PMCID: PMC2629578.-- Supporting information (Suppl. figure S1, tables S1-S4) available at: http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1000364#s5 | RNA polymerases frequently deal with a number of obstacles during transcri...

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52

Genome-wide analysis of factors affecting transcription elongation and DNA repair: a new role for PAF and Ccr4-not in transcription-coupled repair

Gaillard, Hélène; Tous, Cristina; Botet, Javier; González-Aguilera, Cristina; Quintero, María José; Viladevall, Laia; García-Rubio, María L.; Rodríguez-Gil, Alejandrolfonso; Marín, Antonio; Ariño, Joaquín; Revuelta, José L.; Chávez, Sebastián; Aguilera, Andrés
2009-02-06

Digital.CSIC (Spain)

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54

Enhancement of DNA, cDNA synthesis and fidelity at high temperatures by a dimeric single-stranded DNA-binding protein

Perales, Celia; Cava, Felipe; Meijer, Wilfried J.J.; Berenguer, José

Bacterial single-stranded DNA-binding proteins (SSBs) are required for DNA replication and repair. We have over-expressed and purified the native form and two His-tagged fusions of the SSB from Thermus thermophilus (TthSSB). The three proteins were found as dimers in solution. They bound in vitro to...

DRIVER (Spanish)

56

Efecto de la vitamina E(DL alfa-tocoferol) sobre el daño cromosómico en linfocitos de pacientes con ataxia telangiectasia/ Effect of vitamin E (DL alpha-tocopherol) on chromosomal damage in lymphocytes from patients with ataxia telangiectasia

Marcelain C, Katherine; Navarrete S, Carmen Luz; Bravo L, Mireya; Santos A, Manuel; Be R, Cecilia; Pincheira V, Juana
2002-09-01

Resumen en inglés Background: In ataxia telangiectasia (A-T), the lack of a functional ATM kinase is associated with disturbances in the processing of DNA damage and a chronic oxidative stress. These disturbances may be responsible for an increment of chromosomal damage in A-T cells. Aim: To study the in vitro effect of vitamin E (DL-alpha-tocopherol) on the frequency of chromosomal damage of lymphocytes from patients with A-T. Patients and methods: Seven patients with A-T and age-sex matc (mas) hed controls were studied. Chromosomal damage in mitosis was evaluated in lymphocytes cultures both under basal conditions and when G2 repair was prevented by 5 mM caffeine. Results: In cells from patients with A-T, vitamin E induced a 57.1 and 47.9% decrease in chromosomal damage under basal and inhibited G2 repair conditions, respectively. However, there was a non significant improvement in their repair activity. Vitamin E effects on chromosomal damage was not significant in control subjects. Conclusions: Vitamin E reduces chromosomal damage in lymphocytes from patients with ataxia telangiectasia (Rev Med Chile 2002; 130: 957-63)

Scientific Electronic Library Online (Spanish)

58

EFECTO DE LA RADIACIÓN ULTRAVIOLETA-B EN PLANTAS/ EFFECT OF ULTRAVIOLET-B RADIATIONIN PLANTS

Carrasco-Ríos, Libertad
2009-12-01

Resumen en español La luz es uno de los factores más importantes que regulan el crecimiento y desarrollo de las plantas. Sin embargo, el aumento de la radiación ultravioleta-B debido a la acción antropogénica puede tener un impacto negativo en éstas, provocando una disminución de la fotosíntesis y de la producción de biomasa. Esta radiación puede además causar daño en distintas biomoléculas, entre la cuales la más importante es el DNA. En este sentido, el presente trabajo anali (mas) za los estudios recientes sobre la respuesta del crecimiento de plantas expuestas a condiciones de alta radiación ultravioleta y los mecanismos de reparación molecular que en condiciones naturales generan las plantas como estrategia para protegerse de este tipo de radiación Resumen en inglés The light is one of the most important factors that regulate growth and development of plants. However, the increase of the ultraviolet-B radiation due to the antropogenic action can have negative impacts on these processes, producing a decreased photosynthesis and biomass production. The ultraviolet radiation can damage different biomolecules in particular the DNA. This work analyse the last results reported on the responses of the growth of plants exposed to high levels of ultraviolet radiation and the repair mechanisms activated to protect plants against this type of radiation

Scientific Electronic Library Online (Spanish)

59

Dynamic structures of Bacillus subtilis RecN–DNA complexes

Sánchez, Humberto; Cárdenas, Paula P.; Yoshimura, Shige H.; Takeyasu, Kunio; Alonso, Juan Carlos
2008-01-01

Digital.CSIC (Spain)

60

Drosophila mus301/spindle-C Encodes a Helicase With an Essential Role in Double-Strand DNA Break Repair and Meiotic Progression

McCaffrey, Ruth; St Johnston, Daniel; González-Reyes, Acaimo

PMCID: PMC1667076 | mus301 was identified independently in two genetic screens, one for mutants hypersensitive to chemical mutagens and another for maternal mutants with eggshell defects. mus301 is required for the proper specification of the oocyte and for progression through meiosis in the Drosoph...

DRIVER (Spanish)

62

Disparate roles of ATR and ATM in immunoglobulin class switch recombination and somatic hypermutation

Pan-Hammarström, Qiang; Lähdesmäki, Aleksi; Zhao, Yaofeng; Du, Likun; Zhao, Zhihui; Wen, Sicheng; Ruiz-Pérez, Victor L.; Dunn-Walters, Deborah K.; Goodship, Judith A.; Hammarström, Lennart
2006-01-23

Digital.CSIC (Spain)

63

Different genetic requirements for repair of replication-born double-strand breaks by sister-chromatid recombination and break-induced replication

Cortés-Ledesma, Felipe; Tous, Cristina; Aguilera, Andrés

PMCID: PMC2095809 | Homologous recombination (HR) is the major mechanism used to repair double-strand breaks (DSBs) that result from replication, but a study of repair of DSBs specifically induced during S-phase is lacking. Using an inverted-repeat assay in which a DSB is generated by the encounteri...

DRIVER (Spanish)

66

DNA-damage response in the basidiomycete fungus Ustilago maydis relies in a sole Chk1-like kinase

Pérez-Martín, José

Article in Press | Chk1 is a protein kinase that acts as a key signal transducer within the complex network responsible of the cellular response to different DNA damages. It is a conserved element along the eukaryotic kingdom, together with a second checkpoint kinase, called Chk2/Rad53. In fact, all...

DRIVER (Spanish)

68

Characterization of two highly similar Rad51 homologs of Physcomitrella patens

Ayora, Silvia; Piruat, José I.; Luna, Rosa; Reiss, Bernd; Russo, Vincenzo E. A.; Aguilera, Andrés; Alonso, Juan Carlos

PMID: 11829501.-- Final full-text version of the paper available at: http://www.sciencedirect.com/science/journal/00222836 | The moss Physcomitrella patens, which is a land plant with efficient homologous recombination, encodes two Rad51 proteins (PpaRad51.1 and PpaRad51.2). The PpaRad51.1 and PpaRa...

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69

Characterization of two highly similar Rad51 homologs of Physcomitrella patens

Ayora, Silvia; Piruat, José I.; Luna, Rosa; Reiss, Bernd; Russo, Vincenzo E. A.; Aguilera, Andrés; Alonso, Juan Carlos
2002-02-08

Digital.CSIC (Spain)

70

Characterization of a Natural Mutator Variant of Human DNA Polymerase l which Promotes Chromosomal Instability by Compromising NHEJ

Terrados, Gloria; Gapp, Jean-Pascal; Canitrot, Yvan; Garcia-Diaz, Miguel; Bebenek, Katarzyna; Kirchhoff, Tomas; Villanueva, Alberto; Boudsocq, François; Bergoglio, Valerie; Cazaux, Christophe; Kunkel, Thomas A.; Hoffmann, Jean-Sebastien; Blanco, Luis
2009-06-10

Digital.CSIC (Spain)

71

Characterization of SpPol4, a unique X-family DNA polymerase in Schizosaccharomyces pombe

González-Barrera, Sergio; Sánchez, Arancha; Ruiz, José F.; Juárez, Raquel; Picher, Ángel J.; Terrados, Gloria; Andrade, Paula; Blanco, Luis
2005-01-01

Digital.CSIC (Spain)

72

Centromere-localized breaks indicate the generation of DNA damage by the mitotic spindle

Alonso Guerrero, Astrid; Cano Gamero, Mercedes; Trachana, Varvara; Fütterer, Agnes; Pacios-Bras, Cristina; Panadero Díaz-Concha, Nuria; Cigudosa, Juan Cruz; Martínez-Alonso, Carlos; Van Wely, Karel H. M.
2010-02-08

Digital.CSIC (Spain)

73

Caracterización clínica, citogenética y molecular de un nuevo caso de síndrome de Nijmegen en Chile/ Clinical, cytogenetic and molecular characterization of a new case of Nijmegen breakage syndrome in Chile

Marcelain C, Katherine; Aracena A, Mariana; Be R, Cecilia; Navarrete S, Carmen Luz; Moreno H, Rosa; Santos A, Manuel; Pincheira V, Juana
2004-02-01

Resumen en inglés The Nijmegen Breakage Syndrome (NBS) is a rare autosomal recessive disorder associated with microcephaly, immunodeficiency, chromosome instability and cancer proneness. The mutated gene that results in NBS codes for nibrin (Nbs1/p95), a DNA repair protein that is functionally linked to ATM, the kinase protein product of the gene responsible of ataxia-telangiectasia (A-T). We report the clinical, cytogenetic and molecular characterization of a second case of NBS in Chile d (mas) etected by us. The patient is a 7 years old Chilean boy from a consanguineous marriage, with microcephaly, immunodeficiency and acute non lymphocytic leukemia (ANLL). As NBS shares chromosomal and cellular features with A-T, the cytogenetic studies of this patient also included 3 A-T patients. Our results showed that the frequency of spontaneous and X rays induced chromosomal aberrations in NBS are higher than in A-T cells. DNA analysis revealed that the patient is homozygous for the Slavic mutation 657del5 in the NBS1 gene. This finding and the absence of nibrin in patient's cells, confirmed the clinical diagnosis of NBS in our patient (Rev Méd Chile 2004; 132: 211-18)

Scientific Electronic Library Online (Spanish)

74

Bases moleculares del cáncer/ Molecular basis of cancer

Meza-Junco, Judith; Montaño-Loza, Aldo; Aguayo-González, Alvaro
2006-02-01

Resumen en español El cáncer comprende un grupo de enfermedades caracterizadas por proliferación autónoma de células neoplásicas que tienen varias alteraciones, incluyendo mutaciones e inestabilidad genética. Las funciones celulares son controladas por proteínas codificadas por DNA que está organizado en genes y los estudios moleculares han mostrado que el cáncer es el paradigma de una enfermedad genética adquirida. El proceso de producción de las proteínas involucra una serie d (mas) e eventos, cada uno de éstos con sus respectivas enzimas, las cuales también son codificadas por DNA y reguladas por otras proteínas. La mayoría de estos eventos puede verse afectada y eventualmente desencadenar una alteración en la cantidad o estructura proteica, que a su vez afecte la función celular. Sin embargo, mientras que la función celular puede ser alterada por disturbios de un gen, la transformación maligna requiere que ocurran dos o más anormalidades en la misma célula. Si bien, existen mecanismos responsables del mantenimiento y la reparación de DNA, su estructura básica y el orden de sus bases de nucleótidos puede mutar. Estas mutaciones pueden heredarse u ocurrir de manera esporádica y pueden presentarse en todas las células o sólo en las células tumorales. A nivel de los nucleótidos, estas mutaciones pueden ser sustituciones, adiciones o deleciones. Más adelante se discutirán varios oncogenes, incluyendo el p53, c-fms y Ras, que pueden activarse por mutaciones puntuales que originen la sustitución de aminoácidos en puntos críticos de la proteína. Este artículo examina los conceptos actuales relacionados con los mecanismos celulares causales de las alteraciones moleculares que caracterizan el desarrollo del cáncer. Resumen en inglés Cancer is a group of diseases characterized by an autonomous proliferation of neoplastia cells which have a number of alterations, including mutations and genetic instability. Cellular functions are controlled by proteins, and because these proteins are encoded by DNA organized into genes, molecular studies have shown that cancer is a paradigm of acquired genetic disease. The process of protein production involves a cascade of several different steps, each with its attend (mas) ant enzymes, which are also encoded by DNA and regulated by other proteins. Most steps in the process can be affected, eventually leading to an alteration in the amount or structure of proteins, which in turn affects cellular function. However, whereas cellular function may be altered by disturbance of one gene, malignant transformation is thought to require two or more abnormalities occurring in the same cell. Although there are mechanisms responsible for DNA maintenance and repair, the basic structure of DNA and the order of the nucleotide bases can be mutated. These mutations can be inherited or can occur sporadically, and can be present in all cells or only in the tumor cells. At the nucleotide level, these mutations can be substitutions, additions or deletions. Several of the oncogenes discussed below, including the pB3, c-fms, and Ras genes, can be activated by point mutations that lead to aminoacid substitution in critical portions of the protein. This article examines the current concepts relating to cellular mechanism that underlie the molecular alterations that characterize the development of cancer.

Scientific Electronic Library Online (Spanish)

75

Bacillus subtilis SbcC protein plays an important role in DNA inter-strand cross-link repair

Mascarenhas, Judita; Sánchez, Humberto; Tadesse, Serkalem; Kidane, Dawit; Krisnamurthy, Mahalakshmi

This article is available from: http://www.biomedcentral.com/1471-2199/7/20 | [Background] Several distinct pathways for the repair of damaged DNA exist in all cells. DNA modifications are repairedby base excision or nucleotide excision repair, while DNA double strand breaks (DSBs) can be repaired ...

DRIVER (Spanish)

76

Bacillus subtilis SbcC protein plays an important role in DNA inter-strand cross-link repair

Mascarenhas, Judita; Sánchez, Humberto; Tadesse, Serkalem; Kidane, Dawit; Krisnamurthy, Mahalakshmi; Alonso, Juan Carlos; Graumann, Peter L.
2006-06-16

Digital.CSIC (Spain)

77

Autosomal recessive cerebellar ataxias

Palau Martínez, Francesc; Espinós, Carmen
2006-11-17

Digital.CSIC (Spain)

78

Altered Hematopoiesis in Mice Lacking DNA Polymerase μ Is Due to Inefficient Double-Strand Break Repair

Lucas, Daniel; Escudero, Beatriz; Ligos, José Manuel; Segovia, Jose Carlos; Estrada, Juan Camilo; Terrados, Gloria

Polymerase mu (Polμ) is an error-prone, DNA-directed DNA polymerase that participates in non-homologous end-joining (NHEJ) repair. In vivo, Polμ deficiency results in impaired Vκ-Jκ recombination and altered somatic hypermutation and centroblast development. In Polμ−/− mice, hematopoietic developmen...

DRIVER (Spanish)

79

Altered Hematopoiesis in Mice Lacking DNA Polymerase μ Is Due to Inefficient Double-Strand Break Repair

Lucas, Daniel; Escudero, Beatriz; Ligos, José Manuel; Segovia, Jose Carlos; Estrada, Juan Camilo; Terrados, Gloria; Blanco, Luis; Samper, Enrique; Bernad, Antonio
2009-02-01

Digital.CSIC (Spain)

80

A novel role for RecA under non-stress: promotion of swarming motility in Escherichia coli K-12

Gómez-Gómez, José María; Manfredi, Candela; Alonso, Juan Carlos; Blázquez, Jesús
2007-03-28

Digital.CSIC (Spain)

81

A new connection of mRNP biogenesis and export with transcription-coupled repair

Gaillard, Hélène; Wellinger, Ralf Erik; Aguilera, Andrés

PMCID: PMC1919492 | Although DNA repair is faster in the transcribed strand of active genes, little is known about the possible contribution of mRNP biogenesis and export in transcription-coupled repair (TCR). Interestingly, mutants of THO, a transcription complex involved in maintenance of genome i...

DRIVER (Spanish)

82

A new connection of mRNP biogenesis and export with transcription-coupled repair

Gaillard, Hélène; Wellinger, Ralf Erik; Aguilera, Andrés
2007-06-01

Digital.CSIC (Spain)