Targeting inter-duplex junctions in catenated DNA with bidirectional bis-intercalators is a potential strategy for enhancing anticancer effects. In this study, we used d(CGTATACG)2, which forms a tetraplex base-pair j...
Targeting inter-duplex junctions in catenated DNA with bidirectional bis-intercalators is a potential strategy for enhancing anticancer effects. In this study, we used d(CGTATACG)2, which forms a tetraplex base-pair junction that resembles the DNA-DNA contact structure, as a model target for two alkyl-linked diaminoacridine bis-intercalators, DA4 and DA5. Cross-linking of the junction site by the bis-intercalators induced substantial structural changes in the DNA, transforming it from a B-form helical end-to-end junction to an over-wounded side-by-side inter-duplex conformation with A-DNA characteristics and curvature. These structural perturbations facilitated the angled intercalation of DA4 and DA5 with propeller geometry into two adjacent duplexes. The addition of a single carbon to the DA5 linker caused a bend that aligned its chromophores with CpG sites, enabling continuous stacking and specific water-mediated interactions at the inter-duplex contacts. Furthermore, we have shown that the different topological changes induced by DA4 and DA5 lead to the inhibition of topoisomerase 2 activities, which may account for their antitumor effects. Thus, this study lays the foundations for bis-intercalators targeting biologically relevant DNA-DNA contact structures for anticancer drug development.
The impact of COVID-19 on the human body after infection requires further investigation. The protease carried by the virus may interact with cellular proteins, thereby affecting the regulatory pathways. Machine learni...
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OBJECTIVES:The recent emergence of carbapenem-resistant Enterobacterales poses a major and escalating threat to global public health. This study aimed to analyse the global distribution and antimicrobial resistance of...
OBJECTIVES:The recent emergence of carbapenem-resistant Enterobacterales poses a major and escalating threat to global public health. This study aimed to analyse the global distribution and antimicrobial resistance of Enterobacterales harbouring variant OXA-48-like carbapenemase-related genes.
METHODS:Enterobacterales isolates were collected from the Antimicrobial Testing Leadership and Surveillance (ATLAS) programme during 2018-2021. Comprehensive antimicrobial susceptibility testing and β-lactamase gene detection were also conducted, along with statistical analysis of the collected data.
RESULTS:Among the 72 244 isolates, 1934 Enterobacterales isolates were identified to harbour blaOXA-48-like genes, predominantly Klebsiella spp. (86.9%). High rates of multidrug resistance were observed, with only ceftazidime/avibactam and tigecycline showing favourable susceptibility. A discrepancy between the genotype and phenotype of carbapenem resistance was evident: 16.8% (233 out of 1384) of the Enterobacterales isolates with blaOXA-48-like genes exhibited susceptibility to meropenem. Specifically, 37.4% (64/95) of Escherichia coli strains with blaOXA-48-like genes displayed meropenem susceptibility, while the corresponding percentages for Klebsiella pneumoniae and Enterobacter cloacae complex were 25.2% (160/1184) and 0% (0/36), respectively (P < 0.05). Geographical analysis revealed that the highest prevalence of blaOXA-48-like genes occurred in Asia, the Middle East and Eastern Europe. The proportion of K. pneumoniae isolates harbouring blaOXA-232 increased from 23.9% in 2018 to 56.0% in 2021. By contrast, the proportion of blaOXA-48 decreased among K. pneumoniae isolates during 2018-2021.
CONCLUSIONS:This study underscores the widespread and increasing prevalence of blaOXA-48-like genes in Enterobacterales and emphasizes the need for enhanced surveillance, improved diagnostic methods and tailored antibiotic stewardship to combat the spread of these resistant pathogens.
Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide, with approxi-mately 70% to 80% of adults with COPD being undiagnosed. Patients with undiagnosed COPD are at increased...
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Background: Although the 2019 EULAR/ACR classification criteria for systemic lupus erythematosus (SLE) has required at least a positive anti-nuclear antibody (ANA) titer (≥ 1:80), it remains challenging for clinician...
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Acute myeloid leukemia (AML) is a fast-growing and highly fatal blood cancer, and recent research has shown that targeting metabolism may be a promising therapeutic approach for treating AML. One promising target is t...
Acute myeloid leukemia (AML) is a fast-growing and highly fatal blood cancer, and recent research has shown that targeting metabolism may be a promising therapeutic approach for treating AML. One promising target is the human mitochondrial NAD(P)+-dependent malic enzyme (ME2), which is involved in the production of pyruvate and NAD(P)H and the regulation of the NAD+/NADH redox balance. Inhibition of ME2 via silencing ME2 or utilizing its allosteric inhibitor disodium embonate (Na2EA) causes a decrease in pyruvate and NADH, leading to a decrease in producing ATP via cellular respiration and oxidative phosphorylation. ME2 inhibition also decreases NADPH levels, resulting in an increase in reactive oxygen species (ROS) and oxidative stress, which ultimately leads to cellular apoptosis. Additionally, ME2 inhibition reduces pyruvate metabolism and the biosynthetic pathway. ME2 silencing inhibits the growth of xenotransplanted human AML cells, and the allosteric ME2 inhibitor Na2EA demonstrates antileukemic activity against immune-deficient mice with disseminated AML. Both of these effects are a result of impaired energy metabolism in mitochondria. These findings suggest that the targeting ME2 may be an effective strategy for treating AML. Overall, ME2 plays an essential role in energy metabolism of AML cells, and its inhibition may offer a promising approach for AML treatment.
The metabolic landscape of cancer greatly influences antitumor immunity, yet it remains unclear how organ-specific metabolites in the tumor microenvironment influence immunosurveillance. We found that accumulation of ...
The metabolic landscape of cancer greatly influences antitumor immunity, yet it remains unclear how organ-specific metabolites in the tumor microenvironment influence immunosurveillance. We found that accumulation of primary conjugated and secondary bile acids (BAs) are metabolic features of human hepatocellular carcinoma and experimental liver cancer models. Inhibiting conjugated BA synthesis in hepatocytes through deletion of the BA-conjugating enzyme bile acid-CoA:amino acid N-acyltransferase (BAAT) enhanced tumor-specific T cell responses, reduced tumor growth, and sensitized tumors to anti-programmed cell death protein 1 (anti-PD-1) immunotherapy. Furthermore, different BAs regulated CD8+ T cells differently;primary BAs induced oxidative stress, whereas the secondary BA lithocholic acid inhibited T cell function through endoplasmic reticulum stress, which was countered by ursodeoxycholic acid. We demonstrate that modifying BA synthesis or dietary intake of ursodeoxycholic acid could improve tumor immunotherapy in liver cancer model systems.
In inherited neuromuscular disease, Duchenne muscular dystrophy (DMD), glucocorticoids significantly slow disease progression yet impart side effects severe enough to preclude use in a significant proportion of patien...
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Many scientific fields, including human gut microbiome science, collect multivariate count data where the sum of the counts is unrelated to the scale of the underlying system being measured (e.g., total microbial load...
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Most variants identified from genome-wide association studies (GWASs) are non-coding and regulate gene expression. However, many risk loci fail to colocalize with expression quantitative trait loci (eQTLs), potentiall...
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