Search results for "Poly A"

Paclitaxel and beta-lapachone synergistically induce apoptosis in human retinoblastoma Y79 cells by downregulating the levels of phospho-Akt.

2009

Paclitaxel (PTX) and beta-lapachone (LPC) are naturally occurring compounds that have shown a large spectrum of anticancer activity. In this article we show for the first time that PTX/LPC combination induces potent synergistic apoptotic effects in human retinoblastoma Y79 cells. Combination of suboptimal doses of PTX (0.3 nM) and LPC (1.5 microM) caused biochemical and morphological signs of apoptosis at 48 h of treatment. These effects were accompanied by potent lowering in inhibitor of apoptosis proteins and by activation of Bid and caspases 3 and 6 with lamin B and PARP breakdown. PTX/LPC combination acted by favoring p53 stabilization through a lowering in p-Akt levels and in ps166-MDM…

Energy requirement and kinetics of transport of poly(A)-free histone mRNA compared to poly(A)-rich mRNA from isolated L-cell nuclei.

1989

ATP-promoted efflux of poly(A)-rich RNA from isolated nuclei of prelabeled mouse lymphoma L5178y cells has an activation energy of 51.5 kJ/mol, similar to that found for the nuclear envelope nucleoside triphosphatase (48.1 kJ/mol) assumed to be involved in mediating nucleocytoplasmic transport of at least some RNA. Here we show that efflux of two specific poly(A)-rich mRNAs (actin and beta-tubulin) from isolated L-cell nuclei is almost totally dependent on the presence of ATP, while efflux of poly(A)-free histone mRNA (H4, H2B, and H1) also occurs to a marked extent in the absence of this nucleotide. Measurements of temperature dependence of transport rate revealed an activation energy of 5…

Contribution of polyadenylate sequences to the translational efficiency of globin messenger RNAs

1987

mRNAs from reticulocyte polysomes were fractionated by chromatography on poly(U)-Sepharose and thermal elution. The molar ratio of alpha- to beta-globin mRNA was found to be 2:1 and 1:1 respectively in short- and long-poly(A) size classes. Translational analyses indicated that the globin mRNAs containing long poly(A) tracts (with a mean length of about 70 nucleotides) directed protein synthesis with higher rates than did mRNA containing short poly(A) tracts (15-35 nucleotides). Experiments performed with sub-saturating mRNA concentrations showed that the digestion with RNAase H induced a decrease in the translational capacity of both globin mRNAs and an increase in the alpha- to beta-globin…

Modification of antigen-encoding RNA increases stability, translational efficacy, and T-cell stimulatory capacity of dendritic cells.

2006

AbstractAdoptive transfer of dendritic cells (DCs) transfected with in vitro–transcribed, RNA-encoding, tumor-associated antigens has recently entered clinical testing as a promising approach for cancer immunotherapy. However, pharmacokinetic exploration of RNA as a potential drug compound and a key aspect of clinical development is still pending. While investigating the impact of different structural modifications of RNA molecules on the kinetics of the encoded protein in DCs, we identified components located 3′ of the coding region that contributed to a higher transcript stability and translational efficiency. With the use of quantitative reverse transcription–polymerase chain reaction (R…

KRAS-mutated intrahepatic cholangiocarcinoma shows preferential sensitivity towards PARP-1-based interventions

2020

Interaction of polyribosomal components and polyribonucleotides with microtubule proteins

1982

To demonstrate the affinity of RNA-containing polyribosomal components (isolated from L5178y cells) to microtubules, microtubule protein was attached to an insoluble matrix. In contrast to ribosomes, poly(A) (+) mRNA and poly(A)-RNP were found to bind to the matrix. Using synthetic polyribonucleotides, no significant differences in the binding properties of single- and double stranded polymers of different base composition to microtubule protein were observed. However, binding is dependent on the size of the polymer; a minimal chain length of 12 nucleotide units is required.

Use of two-dimensional thin-layer chromatography for the components study of poly(adenosine diphosphate ribose)

1990

Two-dimensional thin-layer chromatography on cellulose plates has been used for separating and quantifying the three adenosine derivatives: AMP, phosphoribosyl AMP (PRAMP), and (PR)2AMP obtained by venom phosphodiesterase digestion of poly(ADP-ribose). In vitro synthesized polymer, up to 300 derivatives in length were studied. Some parameters of the complexity of poly(ADP-ribose) could be deduced from our results: (i) The first branching point appears in fragments of approximately 21 derivatives in length. (ii) The branching points are located at regular distances of approximately 41 derivatives from each other.

Poly-ADP ribose polymerase, xanthine oxidase and nitric oxide synthase expression in kidney tissue of experimental diabetes

2014

Background The spatial distribution of inflammatory and DNA reparation markers in the kidney tissue in diabetes is poorly understood. Aim The present study investigated the role of endothelial and inducible nitric oxide synthase (eNOS and iNOS), Poly ADP ribose polymerase (PARP) xanthine oxidase (XO) in the pathogenesis of streptozotocin-induced diabetic changes in the kidney tissue. Methods Diabetes mellitus was induced in rats by a single injection of streptozotocin (STZ) at a dose of 50 mg/kg. The XO, PARP, eNOS and iNOS protein expression in the kidney was studied by immunohistochemistry. Results Obtained results showed that STZ administration incresed the numbers of PARP and XO-positiv…

Poly(adenosine diphosphate-ribose) polymerase in quail oviduct. Changes during estrogen and progesterone induction

1974

Abstract The activities of the following enzymes have been determined in nuclei of quail oviducts in response to exogenous stimulation of the birds with diethylstilbestrol, used as an estrogen analogue and progesterone: DNA dependent DNA polymerase, DNA dependent RNA polymerase I and II and poly(adenosine diphosphate-ribose) [=poly(ADP-Rib)] polymerase. During primary stimulation with the estrogen analogue the activities of the four DNA dependent polymerases increase to about the same degree. Upon withdrawal of the hormones the levels of the enzymes drop to values known from nuclei from unstimulated quail oviducts. The secondary stimulation with the estrogen analogue causes a significant in…