5 Aza 2 Deoxycytidine
Mostrando 13-24 de 59 artigos, teses e dissertações.
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13. Remodeling of DNA Methylation and Phenotypic and Transcriptional Changes in Synthetic Arabidopsis Allotetraploids1
The joining of different genomes in allotetraploids played a major role in plant evolution, but the molecular implications of this event are poorly understood. In synthetic allotetraploids of Arabidopsis and Cardaminopsis arenosa, we previously demonstrated the occurrence of frequent gene silencing. To explore the involvement of epigenetic phenomena, we inve
American Society of Plant Physiologists.
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14. Antisense oligodeoxynucleotides: synthesis, biophysical and biological evaluation of oligodeoxynucleotides containing modified pyrimidines.
6-Azathymidine, 6-aza-2'-deoxycytidine, 6-methyl-2'-deoxyuridine, and 5,6-dimethyl-2'-deoxyuridine nucleosides have been converted to phosphoramidite synthons and incorporated into oligodeoxynucleotides (ODNs). ODNs containing from 1 to 5 of these modified pyrimidines were compared with known 2'-deoxyuridine, 5-iodo-2'-deoxyuridine, 5-bromo-2'-deoxyuridine,
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15. Transbuccal delivery of 5-Aza-2′-deoxycytidine: Effects of drug concentration, buffer solution, and bile salts on permeation
Delivery of 5-aza-2′-deoxycytidine (decitabine) across porcine buccal mucosa was evaluated as an alternative to the complex intravenous infusion regimen currently used to administer the drug. A reproducible high-performance liquid chromatography method was developed and optimized for the quantitative determination of this drug. Decitabine showed a concentr
Springer-Verlag.
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16. Mechanism of Hb F stimulation by S-stage compounds. In vitro studies with bone marrow cells exposed to 5-azacytidine, Ara-C, or hydroxyurea.
The in vitro effect of S-stage-specific drugs on the fetal hemoglobin (Hb F) potential of erythroid precursors and progenitors was tested by exposing bone marrow cells to 5-aza-2'-deoxycytidine, Ara-C, or hydroxyurea in suspension cultures and reculturing the cells in drug-free clonal cultures. Analysis of Hb F in the erythroblasts present at the end of susp
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17. Gene structure and transcription in mouse cells with extensively demethylated DNA.
In previous work, three clonal cell lines with extremely low DNA methylation levels were derived by multiple consecutive treatments of C3H 10T1/2 C18 (10T1/2) cells with 5-aza-2'-deoxycytidine (5-aza-CdR). In this study we examined the methylation status of genes in these three methyl-deficient clones to assess the specificity of the induced hypomethylation.
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18. Hemimethylation and hypersensitivity are early events in transcriptional reactivation of human inactive X-linked genes in a hamster x human somatic cell hybrid.
Reactivation of the hypoxanthine phosphoribosyltransferase (HPRT) gene on an inactive human X chromosome in a somatic cell hybrid was analyzed following exposure to 5-aza-2'-deoxycytidine. Hemimethylation and chromatin hypersensitivity in the 5' CpG island appeared by 6 h after exposure and continued to increase for 24 h in an exponentially growing cell cult
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19. Activation of an imprinted Igf 2 gene in mouse somatic cell cultures.
The mouse insulin-like growth factor II gene (Igf 2), located on distal chromosome 7, is parentally imprinted such that the paternal allele is expressed while the maternal allele is transcriptionally silent. We derived a cell line from a mouse embryo maternally disomic and paternally deficient for distal chromosome 7 (MatDi7) to determine the stability of ge
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20. Capture and characterization of 5-aza-2'-deoxycytidine-treated C3H/10T1/2 cells prior to transformation.
A model system was developed to capture phenotypically normal cells committed to transformation to address two fundamental questions in cancer biology: (i) what are the earliest events in transformation; and (ii) what is the role of DNA methylation in carcinogenesis? Individual C3H/10T1/2 cells were treated with 5-aza-2'-deoxycytidine, which causes hypomethy
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21. In vivo haematopoietic activity is induced in neurosphere cells by chromatin-modifying agents
Modifications of DNA and chromatin are fundamental for the establishment and maintenance of cell type-specific gene expression patterns that constitute cellular identities. To test whether the developmental potential of fetal brain-derived cells that form floating sphere colonies (neurospheres) can be modified by destabilizing their epigenotype, neurosphere
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22. Incorporation of 5-chlorocytosine into mammalian DNA results in heritable gene silencing and altered cytosine methylation patterns
Cytosine methylation patterns are essential for the proper control of gene expression in higher vertebrates. Although alterations in methylation patterns are frequently observed in human tumors, neither the mechanisms for establishing methylation patterns during normal development nor the mechanisms leading to pathological alterations of methylation patterns
Oxford University Press.
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23. Roles of Cell Division and Gene Transcription in the Methylation of CpG Islands
De novo methylation of CpG islands within the promoters of eukaryotic genes is often associated with their transcriptional repression, yet the methylation of CpG islands located downstream of promoters does not block transcription. We investigated the kinetics of mRNA induction, demethylation, and remethylation of the p16 promoter and second-exon CpG islands
American Society for Microbiology.
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24. Critical Role of Histone Methylation in Tumor Suppressor Gene Silencing in Colorectal Cancer
The mechanism of DNA hypermethylation-associated tumor suppressor gene silencing in cancer remains incompletely understood. Here, we show by chromatin immunoprecipitation that for three genes (P16, MLH1, and the O6-methylguanine-DNA methyltransferase gene, MGMT), histone H3 Lys-9 methylation directly correlates and histone H3 Lys-9 acetylation inversely corr
American Society for Microbiology.