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ACS Infectious Diseases Apr 2024Beyond their requisite functions in many critical DNA processes, the bacterial type II topoisomerases, gyrase and topoisomerase IV, are the targets of fluoroquinolone... (Review)
Review
Beyond their requisite functions in many critical DNA processes, the bacterial type II topoisomerases, gyrase and topoisomerase IV, are the targets of fluoroquinolone antibacterials. These drugs act by stabilizing gyrase/topoisomerase IV-generated DNA strand breaks and by robbing the cell of the catalytic activities of these essential enzymes. Since their clinical approval in the mid-1980s, fluoroquinolones have been used to treat a broad spectrum of infectious diseases and are listed among the five "highest priority" critically important antimicrobial classes by the World Health Organization. Unfortunately, the widespread use of fluoroquinolones has been accompanied by a rise in target-mediated resistance caused by specific mutations in gyrase and topoisomerase IV, which has curtailed the medical efficacy of this drug class. As a result, efforts are underway to identify novel antibacterials that target the bacterial type II topoisomerases. Several new classes of gyrase/topoisomerase IV-targeted antibacterials have emerged, including novel bacterial topoisomerase inhibitors, gyrase inhibitors, triazaacenaphthylenes, spiropyrimidinetriones, and thiophenes. Phase III clinical trials that utilized two members of these classes, gepotidacin (triazaacenaphthylene) and zoliflodacin (spiropyrimidinetrione), have been completed with positive outcomes, underscoring the potential of these compounds to become the first new classes of antibacterials introduced into the clinic in decades. Because gyrase and topoisomerase IV are validated targets for established and emerging antibacterials, this review will describe the catalytic mechanism and cellular activities of the bacterial type II topoisomerases, their interactions with fluoroquinolones, the mechanism of target-mediated fluoroquinolone resistance, and the actions of novel antibacterials against wild-type and fluoroquinolone-resistant gyrase and topoisomerase IV.
Topics: DNA Topoisomerase IV; Fluoroquinolones; DNA Gyrase; Topoisomerase II Inhibitors; Anti-Bacterial Agents; DNA; Mycobacterium tuberculosis
PubMed: 38564341
DOI: 10.1021/acsinfecdis.4c00128 -
Breast Cancer (Tokyo, Japan) May 2024Patients with breast cancer (BC) at advanced stages have poor outcomes because of high rate of recurrence and metastasis. Biomarkers for predicting prognosis remain to...
BACKGROUND
Patients with breast cancer (BC) at advanced stages have poor outcomes because of high rate of recurrence and metastasis. Biomarkers for predicting prognosis remain to be explored. This study aimed to evaluate the relationships between circulating tumor cells (CTCs) and outcomes of BC patients.
PATIENTS AND METHODS
A total of 50 female were enrolled in this study. Their diagnoses were determined by clinical characteristics, image data, and clinical pathology. CTC subtypes and TOP2A gene expression on CTCs were detected by CanPatrol™ technology and triple color in situ RNA hybridization (RNA-ISH), which divided into epithelial CTCs (eCTCs), mesenchymal CTCs (MCTCs), and hybrid CTCs (HCTCs) based on their surface markers. Hormone receptor, including estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) expression, was measured by immunohistochemistry (IHC) method before treatment. The risk factors for predicting recurrence and metastasis were calculated by COX risk regression model. The progression-free survival (PFS) of patients was determined using Kaplan-Meier survival curve.
RESULTS
The patients with a large tumor size (≥ 3 cm) and advanced tumor node metastasis (TNM) stages had high total CTCs (TCTCs) (P < 0.05). These patients also had high TOP2A expression level. COX risk regression analysis indicated that TOP2A expression levels in TCTCs, ER + , HER-2 + , and TNM stages were critical risk factors for recurrence and metastasis of patients (P < 0.05). The PFS of patients with ≥ 5 TCTCs, ≥ 3 HCTCs, and positive TOP2A expression in ≥ 3 TCTCs was significantly longer than that in patient with < 5 TCTCs, < 3 HCTCs, and TOP2A expression in < 3 TCTCs (P < 0.05). In contrast, the PFS of patients with positive hormone receptors (ER + , PR + , HER-2 +) also was dramatically lived longer than that in patients with negative hormone receptor expression.
CONCLUSIONS
High TCTC, HCTCs, and positive TOP2A gene expression on CTCs were critical biomarkers for predicting outcomes of BC patients. Positive hormone receptor expression in BC patients has significant favor PFS.
Topics: Humans; Female; Neoplastic Cells, Circulating; Breast Neoplasms; DNA Topoisomerases, Type II; Middle Aged; Drug Resistance, Neoplasm; Biomarkers, Tumor; Adult; Aged; Receptor, ErbB-2; Prognosis; Receptors, Estrogen; Poly-ADP-Ribose Binding Proteins; Neoplasm Recurrence, Local; Receptors, Progesterone; Gene Expression Regulation, Neoplastic; Progression-Free Survival; Kaplan-Meier Estimate
PubMed: 38561479
DOI: 10.1007/s12282-024-01553-x -
Molecules (Basel, Switzerland) Mar 2024There is an urgent need to discover and develop novel antibacterial agents. Accordingly, we synthesised 2-(piperazin-1-yl)naphtho[2,3-d]thiazole-4,9-dione (PNT), which...
There is an urgent need to discover and develop novel antibacterial agents. Accordingly, we synthesised 2-(piperazin-1-yl)naphtho[2,3-d]thiazole-4,9-dione (PNT), which exhibits antimicrobial activity. The aim of this study was to characterise PNT as an effective antimicrobial agent. Fluorescence microscopy was used to measure PNT's uptake into microbial cells (strains of , , and methicillin-resistant (MRSA)), transmission electron microscopy (TEM) was used to investigate the influence of PNT on the configuration of microbial cells, and a DNA gyrase supercoiling assay was used to investigate whether PNT inhibits DNA gyrase. PNT was taken up by more than 50% of microbial cells within 30 min. Using TEM, hollowed-out bacterial cytoplasms were observed in the specimen treated with PNT, although there was no disintegration of the bacterial membrane. In the DNA gyrase supercoiling assay, a dose-dependent reduction in fluorescence intensity was observed as the concentration of PNT increased. This suggests that PNT is taken up by microbial cells, resulting in cell disruption, and it reveals that one of the mechanisms underlying the antimicrobial activity of PNT is the inhibition of DNA gyrase.
Topics: Staphylococcus; Thiazoles; Methicillin-Resistant Staphylococcus aureus; DNA Gyrase; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 38542913
DOI: 10.3390/molecules29061277 -
Science Advances Mar 2024Bactericidal antibiotics can cause metabolic perturbations that contribute to antibiotic-induced lethality. The molecular mechanism underlying these downstream effects...
Bactericidal antibiotics can cause metabolic perturbations that contribute to antibiotic-induced lethality. The molecular mechanism underlying these downstream effects remains unknown. Here, we show that ofloxacin, a fluoroquinolone that poisons DNA gyrase, induces a cascade of metabolic changes that are dependent on an active SOS response. We identified the SOS-regulated TisB protein as the unique molecular determinant responsible for cytoplasmic condensation, proton motive force dissipation, loss of pH homeostasis, and HO accumulation in cells treated with high doses of ofloxacin. However, TisB is not required for high doses of ofloxacin to interfere with the function of DNA gyrase or the resulting rapid inhibition of DNA replication and lethal DNA damage. Overall, the study sheds light on the molecular mechanisms by which ofloxacin affects bacterial cells and highlights the role of the TisB protein in mediating these effects.
Topics: Escherichia coli; Ofloxacin; Escherichia coli Proteins; DNA Gyrase; Hydrogen Peroxide; Anti-Bacterial Agents
PubMed: 38536908
DOI: 10.1126/sciadv.adk1577 -
FEBS Open Bio Jun 2024Myeloperoxidase (MPO) is found almost exclusively in granulocytes and immature myeloid cells. It plays a key role in the innate immune system, catalysing the formation...
Myeloperoxidase (MPO) is found almost exclusively in granulocytes and immature myeloid cells. It plays a key role in the innate immune system, catalysing the formation of reactive oxygen species that are important in anti-microbial action, but MPO also oxidatively transforms the topoisomerase II (TOP2) poison etoposide to chemical forms that have elevated DNA damaging properties. TOP2 poisons such as etoposide are widely used anti-cancer drugs, but they are linked to cases of secondary acute myeloid leukaemias through a mechanism that involves DNA damage and presumably erroneous repair leading to leukaemogenic chromosome translocations. This leads to the possibility that myeloperoxidase inhibitors could reduce the rate of therapy-related leukaemia by protecting haematopoietic cells from TOP2 poison-mediated genotoxic damage while preserving the anti-cancer efficacy of the treatment. We show here that myeloperoxidase inhibition reduces etoposide-induced TOP2B-DNA covalent complexes and resulting DNA double-strand break formation in primary ex vivo expanded CD34 progenitor cells and unfractionated bone marrow mononuclear cells. Since MPO inhibitors are currently being developed as anti-inflammatory agents this raises the possibility that repurposing of these potential new drugs could provide a means of suppressing secondary acute myeloid leukaemias associated with therapies containing TOP2 poisons.
Topics: Etoposide; Humans; Peroxidase; DNA Damage; DNA Topoisomerases, Type II; Poly-ADP-Ribose Binding Proteins; Topoisomerase II Inhibitors; Antineoplastic Agents; DNA Breaks, Double-Stranded; Bone Marrow Cells; Leukocytes, Mononuclear
PubMed: 38531625
DOI: 10.1002/2211-5463.13799 -
Molecular Cell Apr 2024The topological state of chromosomes determines their mechanical properties, dynamics, and function. Recent work indicated that interphase chromosomes are largely free...
The topological state of chromosomes determines their mechanical properties, dynamics, and function. Recent work indicated that interphase chromosomes are largely free of entanglements. Here, we use Hi-C, polymer simulations, and multi-contact 3C and find that, by contrast, mitotic chromosomes are self-entangled. We explore how a mitotic self-entangled state is converted into an unentangled interphase state during mitotic exit. Most mitotic entanglements are removed during anaphase/telophase, with remaining ones removed during early G1, in a topoisomerase-II-dependent process. Polymer models suggest a two-stage disentanglement pathway: first, decondensation of mitotic chromosomes with remaining condensin loops produces entropic forces that bias topoisomerase II activity toward decatenation. At the second stage, the loops are released, and the formation of new entanglements is prevented by lower topoisomerase II activity, allowing the establishment of unentangled and territorial G1 chromosomes. When mitotic entanglements are not removed in experiments and models, a normal interphase state cannot be acquired.
Topics: DNA Topoisomerases, Type II; Chromosomes; Mitosis; Interphase; Polymers
PubMed: 38521067
DOI: 10.1016/j.molcel.2024.02.025 -
BMC Microbiology Mar 2024The emergence of antimicrobial resistance in bacterial pathogens is a growing concern worldwide due to its impact on the treatment of bacterial infections. The "Trojan...
BACKGROUND
The emergence of antimicrobial resistance in bacterial pathogens is a growing concern worldwide due to its impact on the treatment of bacterial infections. The "Trojan Horse" strategy has been proposed as a potential solution to overcome drug resistance caused by permeability issues.
OBJECTIVE
The objective of our research was to investigate the bactericidal activity and mechanism of action of the "Trojan Horse" strategy using enterobactin conjugated with Ciprofloxacin and Fosfomycin against the antibiotic-resistant Escherichia coli strain OQ866153.
METHODOLOGY
Enterobactin, a mixed ligand of E. coli OQ866153, was conjugated with Ciprofloxacin and Fosfomycin individually to aid active absorption via specific enterobactin binding proteins (FepABCDG). The effectiveness of the conjugates was assessed by measuring their bactericidal activity against E. coli OQ866153, as well as their ability to inhibit DNA gyrase enzyme and biofilm formation.
RESULTS
The Fe-enterobactin-Ciprofloxacin conjugate effectively inhibited the DNA gyrase enzyme (Docking score = -8.597 kcal/mol) and resulted in a lower concentration (25 μg/ml) required to eliminate supercoiled DNA plasmids compared to the parent drug (35 μg/ml; Docking score = -6.264 kcal/mol). The Fe-Enterobactin-Fosfomycin conjugate showed a higher inhibition percentage (100%) of biofilm formation compared to Fosfomycin (21.58%) at a concentration of 2 mg/ml, with docking scores of -5.481 and -3.756 kcal/mol against UDP-N acetylglucosamine 1-carboxyvinyltransferase MurA.
CONCLUSION
The findings of this study suggest that the "Trojan Horse" strategy using enterobactin conjugated with Ciprofloxacin and Fosfomycin can effectively overcome permeability issues caused by efflux proteins and enhance the bactericidal activity of these drugs against antibiotic-resistant strains of E. coli.
Topics: Anti-Bacterial Agents; Fosfomycin; Ciprofloxacin; Escherichia coli; Enterobactin; DNA Gyrase; Microbial Sensitivity Tests
PubMed: 38519885
DOI: 10.1186/s12866-024-03248-x -
Nucleic Acids Research May 2024Formation of programmed DNA double-strand breaks is essential for initiating meiotic recombination. Genetic studies on Arabidopsis thaliana and Mus musculus have...
Formation of programmed DNA double-strand breaks is essential for initiating meiotic recombination. Genetic studies on Arabidopsis thaliana and Mus musculus have revealed that assembly of a type IIB topoisomerase VI (Topo VI)-like complex, composed of SPO11 and MTOPVIB, is a prerequisite for generating DNA breaks. However, it remains enigmatic if MTOPVIB resembles its Topo VI subunit B (VIB) ortholog in possessing robust ATPase activity, ability to undergo ATP-dependent dimerization, and activation of SPO11-mediated DNA cleavage. Here, we successfully prepared highly pure A. thaliana MTOPVIB and MTOPVIB-SPO11 complex. Contrary to expectations, our findings highlight that MTOPVIB differs from orthologous Topo VIB by lacking ATP-binding activity and independently forming dimers without ATP. Most significantly, our study reveals that while MTOPVIB lacks the capability to stimulate SPO11-mediated DNA cleavage, it functions as a bona fide DNA-binding protein and plays a substantial role in facilitating the dsDNA binding capacity of the MOTOVIB-SPO11 complex. Thus, we illustrate mechanistic divergence between the MTOPVIB-SPO11 complex and classical type IIB topoisomerases.
Topics: Adenosine Triphosphate; Arabidopsis; Arabidopsis Proteins; Archaeal Proteins; DNA Breaks, Double-Stranded; DNA Topoisomerases; DNA Topoisomerases, Type II; DNA-Binding Proteins; Endodeoxyribonucleases; Evolution, Molecular; Meiosis; Protein Multimerization
PubMed: 38499490
DOI: 10.1093/nar/gkae181 -
Journal of Enzyme Inhibition and... Dec 2024In this article, a new series of 2-((3,5-disubstituted-2-thioxo-imidazol-1-yl)imino)acenaphthylen-1(2)-ones were synthesized. Imidazole-2-thione with acenaphthylen-one...
In this article, a new series of 2-((3,5-disubstituted-2-thioxo-imidazol-1-yl)imino)acenaphthylen-1(2)-ones were synthesized. Imidazole-2-thione with acenaphthylen-one gave a hybrid scaffold that integrated key structural elements essential for DNA damage direct DNA intercalation and inhibition of the topoisomerase II enzyme. All the synthesized compounds were screened to detect their DNA damage using a terbium fluorescent probe. Results demonstrated that 4-phenyl-imidazoles and in addition to 4-(4-chlorophenyl)imidazoles and would induce detectable potent damage in ctDNA. The four most potent compounds as DNA intercalators were further evaluated for their antiproliferative activity against HepG2, MCF-7 and HCT-116 utilizing the MTT assay. The highest anticancer activity was recorded with compounds and against the breast cancer cell line MCF-7 which were 1.5- and 3- folds more active than , respectively. Therefore, imidazole-2-thione tethered acenaphthylenone derivatives can be considered as promising scaffold for the development of effective dual DNA intercalators and topoisomerase II inhibitors.
Topics: Topoisomerase II Inhibitors; Structure-Activity Relationship; Intercalating Agents; Thiones; Antineoplastic Agents; Cell Line, Tumor; Imidazoles; DNA; Apoptosis; Molecular Docking Simulation; DNA Topoisomerases, Type II; Cell Proliferation
PubMed: 38488131
DOI: 10.1080/14756366.2024.2311818 -
Scientific Reports Mar 2024Our main goal was to design and synthesize novel lomefloxacin derivatives that inhibit the topoisomerase II enzyme, leading to potent anticancer activity. Lomefloxacin...
Our main goal was to design and synthesize novel lomefloxacin derivatives that inhibit the topoisomerase II enzyme, leading to potent anticancer activity. Lomefloxacin derivatives substituted at position 3 and 7 were synthesized and screened for cytotoxic activity utilizing 60 different human cancer cell lines. Furthermore, compounds 3a,b,c,e that revealed potent broad-spectrum anticancer activity (with mean percent GI more than 47%) were further evaluated using five dose concentrations and calculating the GI. Compound 3e was then evaluated for cell cycle analysis and demonstrated cell cycle arrest at the G2-M phase. Moreover, the mechanism of action was determined by determining the topoisomerase inhibitory activity and the molecular modeling study. Compounds 3a,b,c,e showed broad spectrum anticancer activity. Lomefloxacin derivative 5f showed selective cytotoxic activity against melanoma SK-MEL-5 cell line. Compound 3e demonstrated comparable topoisomerase II inhibition to doxorubicin with IC of 0.98 µM.
Topics: Humans; Molecular Structure; Structure-Activity Relationship; Cell Line, Tumor; Antineoplastic Agents; DNA Topoisomerases, Type II; Cell Proliferation; Drug Screening Assays, Antitumor; Molecular Docking Simulation; Dose-Response Relationship, Drug; Fluoroquinolones
PubMed: 38485748
DOI: 10.1038/s41598-024-56313-w