Search results for "RNAs"
showing 10 items of 710 documents
The Status of EGFR Modulates the Effect of miRNA-200c on ZEB1 Expression and Cell Migration in Glioblastoma Cells
2020
Migration of glioblastoma cells into surrounding tissue is one of the main features that makes this tumor incurable. We evaluated whole-genome miRNA expression profiling associated with different EGFR amplification patterns in 30 cases of primary glioblastoma. From the 64 miRNAs that showed differential expression between tumors with a high level of EGFR amplification and tumors without EGFR amplification, 40% were related with cell migration, being miR-200c the most differentially expressed between these two groups. We investigated the effect of miR-200c on ZEB1 expression and cell migration in an in vitro transfection model with a miR-200c mimic, a miR-200c inhibitor and siRNA targeting E…
The guanidinium group as a key part of water-soluble polymer carriers for siRNA complexation and protection against degradation.
2014
Here, the preparation of a novel block copolymer consisting of a statistical copolymer N-(2-hydroxypropyl) methacrylamide-s-N-(3-aminopropyl) methacrylamide and a short terminal 3-guanidinopropyl methacrylamide block is reported. This polymer structure forms neutral but water-soluble nanosized complexes with siRNA. The siRNA block copolymer complexes are first analyzed using agarose gel electrophoresis and their size is determined with fluorescence correlation spectroscopy. The protective properties of the polymer against RNA degradation are investigated by treating the siRNA block copolymer complexes with RNase V1. Heparin competition assays confirm the efficient release of the cargo in vi…
A Post-Labeling Approach for the Characterization and Quantification of RNA Modifications Based on Site-Directed Cleavage by DNAzymes
2011
Deoxyribozymes or DNAzymes are small DNA molecules with catalytic activity originating from in vitro selection experiments. Variants of the two most popular DNAzymes with RNase activity, the 10-23 DNAzyme and the 8-17 DNAzyme, promote efficient in vitro cleavage of the phosphodiester bond in at least 11 out of 16 possible dinucleotide permutations. Judicious choice of the sequences flanking the active core of the DNAzymes permits to direct cleavage activity with high sequence specificity. Here, the harnessing of these features for the analysis of RNA nucleotide modifications by a post-labeling approach is described in detail. DNAzymes are designed such that RNase cleavage is directed precis…
RNase H1 and H2 are differentially regulated to eliminate RNA-DNA hybrids
2019
SUMMARYRNA-DNA hybrids are tightly regulated to ensure genome integrity. The RNase H enzymes, RNase H1 and H2, contribute to chromosomal stability through the removal of RNA-DNA hybrids. Loss of RNase H2 function is implicated in human diseases of the nervous system and cancer. To better understand RNA-DNA hybrid dynamics, we have focused on elucidating the regulation of the RNase H enzymes themselves. Using yeast as a model system, we demonstrate that RNase H1 and H2 are controlled in different manners. RNase H2 is regulated in a strict cell cycle dependent manner, both in terms of its R-loop removal, and ribonucleotide excision repair functions. RNase H1, however, can function independent…
Mechanism of the Antiretroviral Effect of dsRNA
1994
The development of AIDS seems to be linked to an impairment of processes which are induced or activated by double-stranded RNA (dsRNA), such as the biosynthesis of interferon (IFN), production of 2′,5′-oligoadenylate (2-5A), ribonuclease L (RNase L) activity and different cell-mediated immune functions. A restriction of available bioactive dsRNA (or of dsRNA-dependent enzymes) may play an important role in the disease progression. The results summarized in this review show that defects in dsRNA-dependent pathways exhibited by AIDS patients can be reversed, at least in part, by exogenously supplied dsRNA.
Circular RNAs in Sepsis: Biogenesis, Function, and Clinical Significance
2020
Sepsis is a life-threatening condition that occurs when the body responds to an infection that damages it is own tissues. The major problem in sepsis is rapid, vital status deterioration in patients, which can progress to septic shock with multiple organ failure if not properly treated. As there are no specific treatments, early diagnosis is mandatory to reduce high mortality. Despite more than 170 different biomarkers being postulated, early sepsis diagnosis and prognosis remain a challenge for clinicians. Recent findings propose that circular RNAs (circRNAs) may play a prominent role in regulating the patients’ immune system against different pathogens, including bacteria and viruses. Mou…
Epigenetic involvement in Hutchinson-Gilford progeria syndrome: a mini-review.
2013
Hutchinson-Gilford progeria syndrome (HGPS) is a rare human genetic disease that leads to a severe premature ageing phenotype, caused by mutations in the <i>LMNA</i> gene. The <i>LMNA</i> gene codes for lamin-A and lamin-C proteins, which are structural components of the nuclear lamina. HGPS is usually caused by a de novo <i>C1824T</i> mutation that leads to the accumulation of a dominant negative form of lamin-A called progerin. Progerin also accumulates physiologically in normal ageing cells as a rare splicing form of lamin-A transcripts. From this perspective, HGPS cells seem to be good candidates for the study of the physiological mechanisms of ageing…
The Copper-microRNA Pathway Is Integrated with Developmental and Environmental Stress Responses in Arabidopsis thaliana
2021
As an essential nutrient, copper (Cu) scarcity causes a decrease in agricultural production. Cu deficiency responses include the induction of several microRNAs, known as Cu-miRNAs, which are responsible for degrading mRNAs from abundant and dispensable cuproproteins to economize copper when scarce. Cu-miRNAs, such as miR398 and miR408 are conserved, as well as the signal transduction pathway to induce them under Cu deficiency. The Arabidopsis thaliana SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) family member SPL7 binds to the cis-regulatory motifs present in the promoter regions of genes expressed under Cu deficiency, including Cu-miRNAs. The expression of several other SPL transcription f…
Establecimiento de organoides derivados de pacientes con carcinoma colorrectal como modelo para cribado de drogas con acción antitumoral
2022
El cáncer colorrectal (CCR) es la segunda causa de muerte por cáncer a nivel mundial, y es el tercero en incidencia. En los últimos años se han realizado grandes avances para entender mejor los aspectos clínico-patológicos y moleculares del CCR lo que ha conducido a una mejora de las terapias y aumentado la supervivencia de los pacientes. Sin embargo, pese a estos avances muchos pacientes no se benefician de los tratamientos, lo que evidencia la necesidad de búsqueda de nuevos biomarcadores de respuesta y modelos preclínicos adecuados que permitan avanzar hacia una medicina más personalizada. En este contexto, la tecnología de los organoides ha revolucionado el estudio in vitro del cáncer, …
Mecanismos epigenéticos en las células endometriales estromales durante el proceso de decidualización
2012
Durante el ciclo menstrual y bajo el control de las hormonas esteroideas el endometrio experimenta grandes cambios morfológicos y bioquímicos en preparación para la implantación embrionaria. Los principales eventos que tienen lugar son el establecimiento del estado receptivo seguido de un aumento en los niveles de progesterona que induce la decidualización de las células estromales endometriales. La decidualización es una transformación morfológica y funcional del compartimento endometrial estromal necesaria para el control del proceso de invasión embrionaria y la formación de la placenta y por lo tanto para el establecimiento del embarazo. Este proceso está muy bien caracterizado a nivel t…