Search results for "Purine"

R-Roscovitine (Seliciclib) prevents DNA damage-induced cyclin A1 upregulation and hinders non-homologous end-joining (NHEJ) DNA repair.

2010

Abstract Background CDK-inhibitors can diminish transcriptional levels of cell cycle-related cyclins through the inhibition of E2F family members and CDK7 and 9. Cyclin A1, an E2F-independent cyclin, is strongly upregulated under genotoxic conditions and functionally was shown to increase NHEJ activity. Cyclin A1 outcompetes with cyclin A2 for CDK2 binding, possibly redirecting its activity towards DNA repair. To see if we could therapeutically block this switch, we analyzed the effects of the CDK-inhibitor R-Roscovitine on the expression levels of cyclin A1 under genotoxic stress and observed subsequent DNA damage and repair mechanisms. Results We found that R-Roscovitine alone was unable …

2.35 CD73-Generated Extracellular Adenosine Creates Microenvironmental Conditions Favoring Growth and Survival of Chronic Lymphocytic Leukemia Cells

2011

Abstract Abstract 621 CD39 (ecto-nucleoside-triphosphate-diphosphohydrolase-1) and CD73 (5'-nucleotidase) are surface enzymes with extracellular catalytic sites. CD39 hydrolyses ATP/ADP to AMP, which is then converted to adenosine (ADO) by CD73. Once ADO is released in the extracellular milieu, it may re-enter the cell or engage different types of purinergic receptors, eliciting potent autocrine and paracrine cytoprotective, anti-inflammatory and immunosuppressive effects. Several lines of evidence suggest that the tumor microenvironment is marked by increased turnover of extracellular nucleotides and nucleosides, as well as by upregulation of ecto-enzymes that dismantle them. These alterat…

Bidirectional Control between Cholesterol Shuttle and Purine Signal at the Central Nervous System.

2022

Recent studies have highlighted the mechanisms controlling the formation of cerebral cholesterol, which is synthesized in situ primarily by astrocytes, where it is loaded onto apolipoproteins and delivered to neurons and oligodendrocytes through interactions with specific lipoprotein receptors. The “cholesterol shuttle” is influenced by numerous proteins or carbohydrates, which mainly modulate the lipoprotein receptor activity, function and signaling. These molecules, provided with enzymatic/proteolytic activity leading to the formation of peptide fragments of different sizes and specific sequences, could be also responsible for machinery malfunctions, which are associated with neurological…

Synthetic Strategies Towards O6-Substituted Guanine Derivatives and their Application in Medicine

2005

OP20 Risk and predictors of surgery in a newly diagnosed cohort of IBD patients in the biologic era: Results from the EpidemIBD study

2021

Abstract Background The management of inflammatory bowel disease (IBD) has substantially changed in the last decades, both in relation to medical and surgical treatments. Aims Principal: To know the rate of surgery in a newly diagnosed IBD cohort within the first year after diagnosis. Secondary: To describe the type of surgeries and indications in this cohort, and to identify predictive factors for surgery (focused on intestinal resection) in these patients. Methods Prospective, population-based nationwide registry. Adult patients diagnosed with IBD -Crohn’s disease (CD) and ulcerative colitis (UC)- during 2017 in Spain were included and were followed-up for 1 year. Kaplan-Meier curves were…

DNA damage photo-induced by chloroharmine isomers: hydrolysis versus oxidation of nucleobases

2018

Photodynamic therapy (PDT) is an emerging clinical treatment currently being used against a wide range of both cancerous and noncancerous diseases. The search for new active photosensitizers as well as the development of novel selective delivery systems are the major challenges faced in the application of PDT. We investigated herein three chloroharmine derivatives (6-, 8- and 6,8-dichloroharmines) with quite promising intrinsic photochemical tunable properties and their ability to photoinduce DNA damage in order to elucidate the underlying photochemical mechanisms. Data revealed that the three compounds are quite efficient photosensitizers. The overall extent of photo-oxidative DNA damage i…

Principal component analysis on molecular descriptors as an alternative point of view in the search of new Hsp90 inhibitors

2009

Inhibiting a protein that regulates multiple signal transduction pathways in cancer cells is an attractive goal for cancer therapy. Heat shock protein 90 (Hsp90) is one of the most promising molecular targets for such an approach. In fact, Hsp90 is a ubiquitous molecular chaperone protein that is involved in folding, activating and assembling of many key mediators of signal transduction, cellular growth, differentiation, stress-response and apoptothic pathways. With the aim to analyze which molecular descriptors have the higher importance in the binding interactions of these classes, we first performed molecular docking experiments on the 187 Hsp90 inhibitors included in the BindingDB, a pu…

Pathway network inference from gene expression data

2014

[EN] Background: The development of high-throughput omics technologies enabled genome-wide measurements of the activity of cellular elements and provides the analytical resources for the progress of the Systems Biology discipline. Analysis and interpretation of gene expression data has evolved from the gene to the pathway and interaction level, i.e. from the detection of differentially expressed genes, to the establishment of gene interaction networks and the identification of enriched functional categories. Still, the understanding of biological systems requires a further level of analysis that addresses the characterization of the interaction between functional modules. Results: We presen…

Fructose-1,6-Bisphosphate Protects Hippocampal Rat Slices from NMDA Excitotoxicity

2019

Effects of fructose 1,6-bisphosphate (F-1,6-P2) towards N-methyl-d-aspartate NMDA excitotoxicity were evaluated in rat organotypic hippocampal brain slice cultures (OHSC) challenged for 3 h with 30 &mu

IDENTIFICATION AND FUNCTIONAL CHARACTERIZATION OF GPCR23/LPA4 AS A CANDIDATE G PROTEIN-COUPLED RECEPTOR FOR GUANOSINE

2014

La guanosina esercita diverse funzioni a livello del Sistema Nervoso Centrale, coinvolgendo recettori di membrana accoppiati a proteine G (GPCR) non ancora identificati. Pertanto, l’obiettivo della ricerca è stato quello di individuare e caratterizzare uno specifico recettore funzionale per la Guanosina. I dati ottenuti su linee cellulari hanno dimostrato che il legame della guanosina con le membrane plasmatiche è incrementato dall’over-espressione del GPCR23 e ridotto dal suo silenziamento ed hanno evidenziato l’attivazione di un GPCR in risposta alla guanosina. A livello cerebrale il GPCR23 è risultato essere maggiormente espresso nella regione corticale, dove si è dimostrata anche una no…