diffuse competition
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Circular RNAs (circRNAs) make up approximately 10% of the human transcriptome. CircRNAs belong to the broad group of non-coding RNAs and characteristically are formed by backsplicing into a stable circular loop. Their main role is to regulate transcription through the inhibition of miRNAs' expression, termed miRNA sponging. CircRNAs promote tumorigenesis/lymphomagenesis by competitively binding to miRNAs at miRNA binding sites. In diffuse large B-cell lymphoma (DLBCL), several circRNAs have been identified and their expression is related to both progression and response to therapy. DLBCL is the most prevalent and aggressive subtype of B-cell lymphomas and accounts for about 25% to 30% of all non-Hodgkin lymphomas. DLBCL displays great heterogeneity concerning histopathology, biology, and genetics. Patients who have relapsed or have refractory disease after first-line therapy have a very poor prognosis, demonstrating an important unmet need for new treatment options. As more circRNAs are identified in the future, we will better understand their biological roles and potential use in treating cancer, including DLBCL. For example, circAmotl1 promotes nuclear translocation of MYC and upregulation of translational targets of MYC, thus enhancing lymphomagenesis. Another example is circAPC, which is significantly downregulated in DLBCL and correlates with disease aggressiveness and poor prognosis. CircAPC increases expression of the host gene adenomatous polyposis coli (APC), and in doing so inactivates the canonical Wnt/β-catenin signaling and restrains DLBCL growth. MiRNAs belong to the non-coding regulatory molecules that significantly contribute to lymphomagenesis through their target mRNAs. In DLBCL, among the highly expressed miRNAs, are miR-155-5p and miR-21-5p, which regulate NF-ĸB and PI3K/AKT signaling pathways. The aim of this review is to describe the function and mechanism of regulation of circRNAs on miRNAs' expression in DLBCL. This will help us to better understand the regulatory network of circRNA/miRNA/mRNA, and to propose novel therapeutic targets to treat DLBCL.
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Allogeneic transplantation (allo-HCT) is a curative treatment in CLL whose efficacy including the most severe forms had led to the 2006 EBMT recommendations. The advent after 2014 of targeted therapies has revolutionized CLL management, allowing prolonged control to patients who have failed immunochemotherapy and/or have TP53 alterations. We analysed the pre COVID pandemic 2009-2019 EBMT registry. The yearly number of allo-HCT raised to 458 in 2011 yet dropped from 2013 onwards to an apparent plateau above 100. Within the 10 countries who were under the EMA for drug approval and performed 83.5% of those procedures, large initial differences were found but the annual number converged to 2-3 per 10 million inhabitants during the 3 most recent years suggesting that allo-HCT remains applied in selected patients. Long-term follow-up on targeted therapies shows that most patients relapse, some early, with risk factors and resistance mechanisms being described. The treatment of patients exposed to both BCL2 and BTK inhibitors and especially those with double refractory disease will become a challenge in which allo-HCT remains a solid option in competition with emerging therapies that have yet to demonstrate their long-term effectiveness.
- MeSH
- chronická lymfatická leukemie * terapie MeSH
- COVID-19 * etiologie MeSH
- homologní transplantace metody MeSH
- lidé MeSH
- lokální recidiva nádoru MeSH
- příprava pacienta k transplantaci metody MeSH
- retrospektivní studie MeSH
- transplantace hematopoetických kmenových buněk * metody MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Horizont Evropa, v pořadí již devátý rámcový program Evropské unie (EU), je zaměřen na podporu výzkumu a inovací v letech 2021–2027. Má dosud nejambicióznější rozpočet 95,5 miliard eur. Strategickými cíli programu jsou posílení konkurenceschopnosti a udržitelného růstu Evropské unie a jejích členů a efektivní boj proti klimatické změně. Základní rys spočívá v posílení spolupráce členských států s využitím inovací a výzkumu. Strukturou se Horizont Evropa podobá programu Horizont 2020, tj. stojí na třech pilířích: Excelentní věda, Globální výzvy a konkurenceschopnost evropského průmyslu a Inovativní Evropa. Horizont Evropa přináší i několik novinek: mise, evropská partnerství, otevřená věda a otázky genderu. Mezi pěti misemi zaujímají významné místo Malignity, zaměřené na prevenci, časnou diagnostiku, optimální léčbu a následnou péči. Evropská partnerství jsou novým typem spolupráce soukromého a veřejného sektoru zaměřeným na významná výzkumná témata a inovace. Otevřená věda znamená povinnost umožnit přístup k publikacím a výzkumným datům a genderové otázky mají zajistit rovné příležitosti ve vědě a výzkumu i práci v Evropě.
Horizon Europe is the 9th framework programme of European Union (EU) funding research and innovation with the biggest budget ever of €95.5 billion. The main aims of the programme are to boost competitiveness and growth of European Union, to achieve EU sustainable development and to tackle climate change. The programme facilitates collaboration between member states and strengthens the impact of research and innovations. The structure of HEU is similar as in Horizon 2020 based on three pillars: Excellent Science, Global Challenges and European Industrial Competitiveness, and Innovative Europe. Horizon Europe brings several novelties as missions, European partnerships, open science, and gender issues. There are five mission areas and the first one of them is Cancer Mission. European partnership is a new form of objective-driven collaborations bringing together private and/or public partners together to address some of Europe´s most important challenges through concerted research and innovation initiatives. Open science policy is mandatory and refers to the open access to publications and open science principles. In the frame of gender equality strategy, the EU has established a well-established regulatory framework on gender equality, including binding directives, which apply widely across the labour market including the research sector.
- MeSH
- Evropská unie MeSH
- lékařství MeSH
- rozšiřování inovací * MeSH
- výzkumný projekt MeSH
- Publikační typ
- práce podpořená grantem MeSH
The bacterial division apparatus catalyses the synthesis and remodelling of septal peptidoglycan (sPG) to build the cell wall layer that fortifies the daughter cell poles. Understanding of this essential process has been limited by the lack of native three-dimensional views of developing septa. Here, we apply state-of-the-art cryogenic electron tomography (cryo-ET) and fluorescence microscopy to visualize the division site architecture and sPG biogenesis dynamics of the Gram-negative bacterium Escherichia coli. We identify a wedge-like sPG structure that fortifies the ingrowing septum. Experiments with strains defective in sPG biogenesis revealed that the septal architecture and mode of division can be modified to more closely resemble that of other Gram-negative (Caulobacter crescentus) or Gram-positive (Staphylococcus aureus) bacteria, suggesting that a conserved mechanism underlies the formation of different septal morphologies. Finally, analysis of mutants impaired in amidase activation (ΔenvC ΔnlpD) showed that cell wall remodelling affects the placement and stability of the cytokinetic ring. Taken together, our results support a model in which competition between the cell elongation and division machineries determines the shape of cell constrictions and the poles they form. They also highlight how the activity of the division system can be modulated to help generate the diverse array of shapes observed in the bacterial domain.
OBJECTIVES: To investigate the fitness effects of large blaCTX-M-15-harbouring F2:A1:B- plasmids on their native Escherichia coli ST131 H30Rx hosts. METHODS: We selected five E. coli ST131 H30Rx isolates of diverse origin, each carrying an F2:A1:B- plasmid with the blaCTX-M-15 gene. The plasmid was eliminated from each isolate by displacement using an incompatible curing plasmid, pMDP5_cureEC958. WGS was performed to obtain complete chromosome and plasmid sequences of original isolates and to detect chromosomal mutations in 'cured' clones. High-throughput competition assays were conducted to determine the relative fitness of cured clones compared with the corresponding original isolates. RESULTS: We were able to successfully eliminate the F2:A1:B- plasmids from all five original isolates using pMDP5_cureEC958. The F2:A1:B- plasmids produced non-significant fitness effects in three isolates and moderate reductions in relative fitness (3%-4%) in the two remaining isolates. CONCLUSIONS: We conclude that F2:A1:B- plasmids pose low fitness costs in their E. coli ST131 H30Rx hosts. This plasmid-host fitness compatibility is likely to promote the maintenance of antibiotic resistance in this clinically important E. coli lineage.
The Leishmania major leucyl-aminopeptidase (LAPLm), a member of the M17 family of proteases, is a potential drug target for treatment of leishmaniasis. To better characterize enzyme properties, recombinant LAPLm (rLAPLm) was expressed in Escherichia coli. A LAPLm gene was designed, codon-optimized for expression in E. coli, synthesized and cloned into the pET-15b vector. Production of rLAPLm in E. coli Lemo21(DE3), induced for 4 h at 37 °C with 400 μM IPTG and 250 μM l-rhamnose, yielded insoluble enzyme with a low proportion of soluble and active protein, only detected by an anti-His antibody-based western-blot. rLAPLm was purified in a single step by immobilized metal ion affinity chromatography. rLAPLm was obtained with a purity of ~10% and a volumetric yield of 2.5 mg per liter, sufficient for further characterization. The aminopeptidase exhibits optimal activity at pH 7.0 and a substrate preference for Leu-p-nitroanilide (appKM = 30 μM, appkcat = 14.7 s-1). Optimal temperature is 50 °C, and the enzyme is insensitive to 4 mM Co2+, Mg2+, Ca2+ and Ba2+. However, rLAPLm was activated by Zn2+, Mn2+ and Cd2+ but is insensitive towards the protease inhibitors PMSF, TLCK, E-64 and pepstatin A, being inhibited by EDTA and bestatin. Bestatin is a potent, non-competitive inhibitor of the enzyme with a Ki value of 994 nM. We suggest that rLAPLm is a suitable target for inhibitor identification.
- MeSH
- aminopeptidasy * biosyntéza chemie genetika izolace a purifikace MeSH
- Escherichia coli * genetika metabolismus MeSH
- kinetika MeSH
- Leishmania major * enzymologie genetika MeSH
- protozoální proteiny * biosyntéza chemie genetika izolace a purifikace MeSH
- rekombinantní proteiny biosyntéza chemie genetika izolace a purifikace MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The rise in multidrug-resistant bacteria defines the need for identification of new antibacterial agents that are less prone to resistance acquisition. Compounds that simultaneously inhibit multiple bacterial targets are more likely to suppress the evolution of target-based resistance than monotargeting compounds. The structurally similar ATP binding sites of DNA gyrase and topoisomerase Ⅳ offer an opportunity to accomplish this goal. Here we present the design and structure-activity relationship analysis of balanced, low nanomolar inhibitors of bacterial DNA gyrase and topoisomerase IV that show potent antibacterial activities against the ESKAPE pathogens. For inhibitor 31c, a crystal structure in complex with Staphylococcus aureus DNA gyrase B was obtained that confirms the mode of action of these compounds. The best inhibitor, 31h, does not show any in vitro cytotoxicity and has excellent potency against Gram-positive (MICs: range, 0.0078-0.0625 μg/mL) and Gram-negative pathogens (MICs: range, 1-2 μg/mL). Furthermore, 31h inhibits GyrB mutants that can develop resistance to other drugs. Based on these data, we expect that structural derivatives of 31h will represent a step toward clinically efficacious multitargeting antimicrobials that are not impacted by existing antimicrobial resistance.
- MeSH
- adenosintrifosfát chemická syntéza chemie farmakologie MeSH
- antibakteriální látky chemická syntéza chemie farmakologie MeSH
- DNA gyráza metabolismus MeSH
- DNA-topoisomerasa IV antagonisté a inhibitory metabolismus MeSH
- Escherichia coli účinky léků enzymologie patogenita MeSH
- krystalografie rentgenová MeSH
- mikrobiální testy citlivosti MeSH
- molekulární struktura MeSH
- simulace molekulového dockingu MeSH
- Staphylococcus aureus účinky léků enzymologie patogenita MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: Gastrointestinal microbiota may be involved in Helicobacter pylori-associated gastric cancer development. The aim of this study was to explore the possible microbial mechanisms in gastric carcinogenesis and potential dysbiosis arising from H. pylori infection. DESIGN: Deep sequencing of the microbial 16S ribosomal RNA gene was used to investigate alterations in paired gastric biopsies and stool samples in 58 subjects with successful and 57 subjects with failed anti-H. pylori treatment, relative to 49 H. pylori negative subjects. RESULTS: In H. pylori positive subjects, richness and Shannon indexes increased significantly (both p<0.001) after successful eradication and showed no difference to those of negative subjects (p=0.493 for richness and p=0.420 for Shannon index). Differential taxa analysis identified 18 significantly altered gastric genera after eradication. The combination of these genera into a Microbial Dysbiosis Index revealed that the dysbiotic microbiota in H. pylori positive mucosa was associated with advanced gastric lesions (chronic atrophic gastritis and intestinal metaplasia/dysplasia) and could be reversed by eradication. Strong coexcluding interactions between Helicobacter and Fusobacterium, Neisseria, Prevotella, Veillonella, Rothia were found only in advanced gastric lesion patients, and were absent in normal/superficial gastritis group. Changes in faecal microbiota included increased Bifidobacterium after successful H. pylori eradication and more upregulated drug-resistant functional orthologs after failed treatment. CONCLUSION: H. pylori infection contributes significantly to gastric microbial dysbiosis that may be involved in carcinogenesis. Successful H. pylori eradication potentially restores gastric microbiota to a similar status as found in uninfected individuals, and shows beneficial effects on gut microbiota.
- MeSH
- antibakteriální látky terapeutické užití MeSH
- biopsie metody MeSH
- dysbióza * diagnóza mikrobiologie MeSH
- feces mikrobiologie MeSH
- gastritida atrofická * mikrobiologie patologie MeSH
- Helicobacter pylori * izolace a purifikace patogenita MeSH
- infekce vyvolané Helicobacter pylori * farmakoterapie patologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- metaplazie mikrobiologie patologie MeSH
- mikrobiální interakce MeSH
- nádory žaludku * mikrobiologie patologie MeSH
- RNA ribozomální 16S izolace a purifikace MeSH
- střevní mikroflóra genetika MeSH
- žaludeční sliznice mikrobiologie patologie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Yeast form complex highly organized colonies in which cells undergo spatiotemporal phenotypic differentiation in response to local gradients of nutrients, metabolites, and specific signaling molecules. Colony fitness depends on cell interactions, cooperation, and the division of labor between differentiated cell subpopulations. Here, we describe the regulation and dynamics of the expansion of papillae that arise during colony aging, which consist of cells that overcome colony regulatory rules and disrupt the synchronized colony structure. We show that papillae specifically expand within the U cell subpopulation in differentiated colonies. Papillae emerge more frequently in some strains than in others. Genomic analyses further revealed that the Whi2p-Psr1p/Psr2p complex (WPPC) plays a key role in papillae expansion. We show that cells lacking a functional WPPC have a sizable interaction-specific fitness advantage attributable to production of and resistance to a diffusible compound that inhibits growth of other cells. Competitive superiority and high relative fitness of whi2 and psr1psr2 strains are particularly pronounced in dense spatially structured colonies and are independent of TORC1 and Msn2p/Msn4p regulators previously associated with the WPPC function. The WPPC function, described here, might be a regulatory mechanism that balances cell competition and cooperation in dense yeast populations and, thus, contributes to cell synchronization, pattern formation, and the expansion of cells with a competitive fitness advantage.
- MeSH
- membránové proteiny genetika metabolismus MeSH
- proliferace buněk fyziologie MeSH
- proteinfosfatasy genetika metabolismus MeSH
- regulace genové exprese u hub fyziologie MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- signální transdukce fyziologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We report a new configuration for enhancing the performance of scanning electrochemical microscopy (SECM) via heating of the substrate electrode. A flattened Pt microwire was employed as the substrate electrode. The substrate was heated by an alternating current (AC), resulting in an increased mass transfer between the wire surface and the bulk solution. The electrochemical response of the Pt wire during heating was investigated by means of cyclic voltammetry (CV). The open circuit potential (OCP) of the wire was recorded over time, while varied heating currents were applied to investigate the time needed for establishing steady-state conditions. Diffusion layer studies were carried out by performing probe approach curves (PACs) for various measuring modes of SECM. Finally, imaging studies of a heated substrate electrode surface, applying feedback, substrate generation/tip collection (SG/TC), and the competition mode of SECM, were performed and compared with room temperature results.
