Search Results (172)

Carboxamide derivatives are a promising class of compounds in anticancer drug discovery, owing to their ability to interact with multiple oncogenic targets and their favorable pharmacological profiles. In this study, we report the design, synthesis, and biological evaluation of a series of N-substituted 1H-indole-2-carboxamides as potential anticancer agents. The synthesized compounds were assessed for antiproliferative activity using the MTT assay against MCF-7 (breast cancer), K-562 (leukemia), and HCT-116 (colon cancer) cell lines, with normal human dermal fibroblasts included as a non-cancerous control. Several compounds demonstrated notable cytotoxicity and selectivity. Compounds 12, 14, and 4 exhibited potent activity against K-562 cells, with IC₅₀ values of 0.33 µM, 0.61 µM, and 0.61 µM, respectively. Compound 10 showed the most significant activity against HCT-116 cells (IC₅₀ = 1.01 µM) with a high selectivity index (SI = 99.4). Moderate cytotoxicity was observed against MCF-7 cells. To elucidate the mechanism of action, molecular docking and induced-fit docking studies were conducted against key cancer-related targets, including topoisomerase–DNA (PDB ID: 5ZRF), PI3Kα (4L23), and EGFR (3W32), revealing favorable binding interactions. Additionally, principal component analysis of molecular descriptors indicated that the compounds possess promising drug-like and lead-like properties, particularly compound 10. Overall, this study highlights N-substituted indole-2-carboxamides as promising scaffolds for further optimization. The integration of synthetic chemistry, biological assays, and computational modeling provides a robust foundation for the continued development of these compounds as potential anticancer agents. Full article

Searching for new anticancer drugs is a significant challenge for the medical community due to the current limitations of existing treatments. The primary objective of this study was to design and optimize multi-targeted drug candidates based on a quinoline scaffold. In this paper, we adopt various in silico techniques, including molecular docking, molecular dynamics simulations, and ADMET property modeling, to predict the binding affinity and interactions of 7-ethyl-10-hydroxycamptothecin derivatives with multiple biological targets. The interactions of these compounds with three potential molecular targets, topoisomerase I, bromodomain-containing protein 4, and ATP-binding cassette sub-family G member 2 proteins, were analyzed. It has been previously proved that the inhibition of these molecular targets may have beneficial effects on cancer treatment. The designed chemical compounds can effectively interact with selected proteins, thereby establishing their potential as drug candidates. Molecular docking revealed promising binding affinities, with topoisomerase I docking scores ranging from −9.0 to −10.3 kcal/mol, BRD4 scores from −6.6 to −8.0 kcal/mol, and ABCG2 scores from −8.0 to −10.0 kcal/mol. Furthermore, the ADMET property analysis indicates promising pharmacological profiles, protein binding affinity, selectivity, and bioavailability while minimizing toxicity. For example, satisfactory logP values have been demonstrated in the favorable range for bioavailability after oral administration. Additionally, several compounds exhibited predicted aqueous solubility values greater than −3, suggesting moderate-to-good solubility, which is crucial for oral drug delivery. Full article

Breast cancer is a prevalent type of cancer worldwide, leading to both high incidence and mortality, and hence, effective and safe drugs are needed. Because of this, the use of natural products and their derivatives has become a popular strategy for developing new chemotherapeutic agents. In this study, 17 new sesquiterpene-aryl derivatives were synthesized using (−)-drimenol as the starting material. The cytotoxicity of these semi-synthetic derivatives was determined in MCF-7 cells, a breast cancer model, and in a non-tumor cell line, MCF-10, to evaluate selectivity. The results show that five of these sesquiterpene derivatives had IC₅₀ values between 9.0 and 25 µM. Of these, compound 14c stands out for its higher cytotoxicity in MCF-7 cells but lower cytotoxicity in MCF-10 cells, being more selective than daunorubicin (selective index values of 44 and 28, respectively). In addition, compound 14c induced oxidative stress in MCF-7 cells, activated caspases-3/7, and selectively inhibited topoisomerase II (TOP2) versus topoisomerase I (TOP1) in MCF-7 cells. In silico studies allowed us to propose a binding mode for 14c to the TOP2 DNA complex to validate the experimental results. Therefore, this study demonstrated the importance of aryl-sesquiterpene structures and their promising profiles in the search for new bioinspired antitumor drugs in natural products. Full article

Background: Cancer remains a leading cause of morbidity and mortality worldwide. According to the World Health Organization (WHO), lung cancer is the most prevalent type of cancer among both men and women. Despite the various pharmacological and biological treatments available for lung cancer, their effectiveness has often fallen short, and the side effects can be severe. Therefore, there is an ongoing need to identify and develop novel compounds with enhanced anti-tumor efficacy and improved safety profiles. Research has shown that fluoroquinolone derivatives exhibit a broad cytotoxic spectrum comparable to other drugs used in clinical chemotherapy. Objective: The aim of this work was to synthesize and evaluate the cytotoxic, anti-proliferative, and anti-tumor effects of FQB-1, a novel fluoroquinolone derivative. Results: In silico molecular docking analysis demonstrated a strong interaction between FQB-1 and human topoisomerase, with a binding affinity score of –9.8 kcal/mol. In vitro cytotoxicity and anti-proliferative assays were conducted using the Lewis Lung Carcinoma (LLC) cell line. FQB-1 was tested at concentrations of 2.5, 5.0, 25.0, 50.0, 100.0, and 150.0 µg/mL. Significant cytotoxic and anti-proliferative effects were observed at concentrations of 50–150 µg/mL after 24 h of treatment. To evaluate FQB-1′s efficacy in vivo, a syngeneic tumor model was established in C57BL/6 mice. Treatment with FQB-1 (100 mg/kg) resulted in a marked reduction in tumor volume compared to the untreated control group. Histopathological analysis of tumor tissues from treated animals revealed a decrease in mitotic index and an increase in necrotic regions, indicating compromised tumor viability. Conclusions: FQB-1 exhibits cytotoxic and anti-proliferative effects and can reduce tumor growth while compromising tumor viability. Full article

Human topoisomerase IIα and IIβ regulate DNA topology and knots in chromosomes during crucial cellular processes, making these enzymes common targets for anticancer drugs. However, selective inhibition of topoisomerase IIα (TOP2A) is desired to decrease adverse effects, which may be mediated by topoisomerase IIβ (TOP2B). The main region of difference between the two isoforms is the intrinsically disordered C-terminal domain (CTD), which is being studied as a target for selective inhibition. Our previous work examined several regions within the CTD to determine whether those regions impact biochemical function. In this current study, we designed and constructed four TOP2A mutants with amino acid substitutions in the CTD, which were then assessed for impact on biochemical activity. V1482D exhibited increased levels of relaxation, while both V1482D and K1520I exhibited increased levels of decatenation. No major impact on DNA cleavage or binding were observed with any of the mutants. The isolated impact of the changes on relaxation and decatenation supports the concept that the CTD can affect one aspect of the enzyme’s function in an isolated manner, which was seen in our previous study. Taken together, these results suggest that modification of specific positions within the CTD affects substrate selection. These results are mapped onto the CTD for consideration of potential regions to target for inhibition of TOP2A. Full article

Background: Novel norfloxacin derivatives were synthesized, characterized, and screened for their antibacterial activity against Gram-positive strain S. aureus ATCC 6538 and Gram-negative strains; E. coli ATCC 25923, K. pneumoniae ATCC 10031, and P. aeruginosa ATCC 27853 using the agar cup diffusion method. Results: The results revealed that compounds 6–17 exhibited more potent activity towards S. aureus ATCC 6538 with MIC values of 0.21–3.61 µM than norfloxacin with a MIC of 7.83 µM. The most potent compound, 6, showed 37-fold more potency than norfloxacin. More importantly, compound 7 exhibited more potent activity against MRSA than norfloxacin, with MIC values of 0.80 and 1.96 µM, respectively. Meanwhile, compounds 15 and 16 have potent activity towards the Gram-negative strains with MIC values of 0.20–0.79 µM compared with norfloxacin with a MIC of 0.24 µM. Moreover, the potent compounds showed higher activity towards topoisomerase II enzymes, especially against topoisomerase IV, which confirms the docking study with the S. aureus gyrase enzyme active binding site (PDB ID: 2XCT). In addition, cytotoxicity assays of the most potent compounds showed that compounds 6, 7, 15, and 16 have negligible risks of toxic effects when evaluated against the normal cell line WI 38. Conclusions: The docking study of the most potent compounds 6, 7, 15, and 16 on the gyrase enzyme active site (PDB: 2XCT) aligns their antibacterial activity and topoisomerase inhibition. The physicochemical and pharmacokinetic characteristics of the target derivatives were forecasted via SwissADME. Hence, these compounds are considered promising antibacterial candidates that require further optimization. Full article

The Saccharomyces cerevisiae chromosomal architectural protein Hmo1 is categorized as an HMGB protein, as it contains two HMGB motifs that bind DNA in a structure-specific manner. However, Hmo1 has a basic C-terminal domain (CTD) that promotes DNA bending instead of an acidic one found in a canonical HMGB protein. Hmo1 has diverse functions in genome maintenance and gene regulation. It is implicated in DNA damage tolerance (DDT) that enables DNA replication to bypass lesions on the template. Hmo1 is believed to direct DNA lesions to the error-free template switching (TS) pathway of DDT and to aid in the formation of the key TS intermediate sister chromatid junction (SCJ), but the underlying mechanisms have yet to be resolved. In this work, we used genetic and molecular biology approaches to further investigate the role of Hmo1 in DDT. We found extensive functional interactions of Hmo1 with components of the genome integrity network in cellular response to the genotoxin methyl methanesulfonate (MMS), implicating Hmo1 in the execution or regulation of homology-directed DNA repair, replication-coupled chromatin assembly, and the DNA damage checkpoint. Notably, our data pointed to a role for Hmo1 in directing SCJ to the nuclease-mediated resolution pathway instead of the helicase/topoisomerase mediated dissolution pathway for processing/removal. They also suggested that Hmo1 modulates both the recycling of parental histones and the deposition of newly synthesized histones on nascent DNA at the replication fork to ensure proper chromatin formation. We found evidence that Hmo1 counteracts the function of histone H2A variant H2A.Z (Htz1 in yeast) in DDT possibly due to their opposing effects on DNA resection. We showed that Hmo1 promotes DNA negative supercoiling as a proxy of chromatin structure and MMS-induced DNA damage checkpoint signaling, which is independent of the CTD of Hmo1. Moreover, we obtained evidence indicating that whether the CTD of Hmo1 contributes to its function in DDT is dependent on the host’s genetic background. Taken together, our findings demonstrated that Hmo1 can contribute to, or regulate, multiple processes of DDT via different mechanisms. Full article

Background/Objectives: Breast cancer is the most prevalent cancer in adult women. Currently, new therapies and protein determinations with prognostic value are under development. Fascin (encoded by the FSCN1 gene) is an actin-binding protein that is critical for the development of cytoplasmic projections that are essential for tumor invasion. DNA topoisomerase 2-alpha (TOP2A) is a nuclear protein crucial for ATP-dependent breakage, passage, and rejoining of double-stranded DNA and cell division. Both proteins are associated with higher proliferation rates and worse prognosis in breast cancer and together can provide comprehensive information on prognosis and treatment response. Methods: We simultaneously assessed fascin expression and TOP2A/CEP17 DNA copy number ratios in various histological and molecular subtypes. Additionally, these markers were analyzed along with previously established diagnostic markers and other relevant clinical data. Results: Our series included 265 patients, four of whom were male, and all of which were diagnosed with breast carcinoma. Of the 265 patients initially included, sufficient material for analysis was available for 175 cases, as some samples were excluded because of insufficient tissue quantity, poor preservation, or lack of hybridization in certain assays. Immunohistochemical (IHC) expression of fascin, both in its aggregated form and by category, showed no association with the TOP2A gene alteration ratio. Fascin expression was significantly associated with histological subtype (p < 0.001), molecular subtype (p < 0.001), hormone receptor (HR) (p < 0.001), BCL2 (p = 0.003), Ki67 (p = 0.002), and histological grade (p < 0.001). TOP2A was significantly associated with molecular subtype (p = 0.041), Ki67 (p = 0.048), and histological grade (p = 0.033). In our study, molecular subtype (p = 0.037) emerged as an independent variable for the complete histological response to neoadjuvant treatment. Multivariate analysis linked pathological stage (p = 0.002) and estrogen receptor (ER) expression (p = 0.004) to overall survival (OS) and disease-free survival (DFS). Conclusions: No statistical relationship was evident between fascin expression (IHC) and the TOP2A copy ratio. The results of this study suggested that the mechanisms of increased cell proliferation associated with alterations in fascin and TOP2A are independent. Full article

Lactation traits are critical economic attributes in domestic animals. This study investigates genetic markers and functional genes associated with lactation traits in Xinjiang donkeys. We analyzed 112 Xinjiang donkeys using 10× whole genome re-sequencing to obtain genome-wide single nucleotide polymorphisms (SNPs). Genome-wide association analyses were conducted using PLINK 2.0 and GEMMA 0.98.5 software, employing mixed linear models to assess several lactation traits: average monthly milk yield (AY), fat percentage (FP), protein percentage (PP), and lactose percentage (LP). A total of 236 SNPs were significantly associated with one or more milk production traits (p < 0.000001). While the two-software identified distinct SNP associations, they consistently detected the same 11, 95, 5, and 103 SNPs for AY, FP, PP, and LP, respectively. Several of these SNPs are located within potential candidate genes, including glycosylphosphatidylinositol anchored high density lipoprotein binding protein 1 (GPIHBP1), FLII actin remodeling protein (FLII), mitochondrial topoisomerase 1 (TOP1MT), thirty-eight-negative kinase 1 (TNK1), polo like kinase 1 (PLK1), notch homolog 1 (NOTCH1), developmentally regulated GTP-binding protein 2 (DRG2), mitochondrial elongation factor 2 (MIEF2), glutamine-fructose-6-phosphate transaminase 2 (GFPT2), and dual-specificity tyrosine phosphorylation-regulated kinase 2 (DYRK2). Additionally, we validated the polymorphism of 16 SNPs (10 genes) using Kompetitive Allele Specific PCR, revealing that TOP1MT_g.9133371T > C, GPIHBP1_g.38365122C > T, DRG2_g.4912631C > A, FLII_g.5046888C > T, and PLK1_g.23585377T > C were significantly correlated with average daily milk yield and total milk yield in the studied donkeys. This study represents the first genome-wide association analysis of markers and milk components in Xinjiang donkeys, offering valuable insights into the genetic mechanisms underlying milk production traits. Further research with larger sample sizes is essential to confirm these findings and identify potential causal genetic variants. Full article

Cancer remains a leading cause of death worldwide, highlighting the urgent need for novel and more effective treatments. Natural products, with their structural diversity, represent a valuable source for the discovery of anticancer compounds. In this study, we screened 750 Antarctic extracts to identify potential inhibitors of human topoisomerase 1 (hTOP1), a key enzyme in DNA replication and repair, and a target of cancer therapies. Bioassay-guided fractionation led to the identification of palmitic acid (PA) as the active compound from the Antarctic sponge Artemisina plumosa, selectively inhibiting hTOP1. Our results demonstrate that PA irreversibly blocks hTOP1-mediated DNA relaxation and specifically inhibits the DNA religation step of the enzyme’s catalytic cycle. Unlike other fatty acids, PA exhibited unique specificity, which we confirmed through comparisons with linoleic acid. Molecular dynamics simulations and binding assays further suggest that PA interacts with hTOP1-DNA complexes, enhancing the inhibitory effect in the presence of camptothecin (CPT). These findings identify PA as a hTOP1 inhibitor with potential therapeutic implications, offering a distinct mechanism of action that could complement existing cancer therapies. Full article

Background/Objectives: Antimicrobial resistance and oxidative stress are major global health challenges, necessitating the development of novel therapeutic agents. Pyrazole derivatives, known for their diverse pharmacological properties, hold promise in addressing these issues. This study aimed to synthesize new mono- and bis-pyrazole derivatives using an eco-friendly, catalyst-free approach and evaluate their antioxidant, antibacterial, and antifungal activities, supported by in silico ADMET profiling, molecular docking, and Density Functional Theory (DFT) analysis. Methods: The compounds were synthesized via a green condensation reaction and characterized using NMR and mass spectrometry, which was verified by DFT analysis. Biological activities were assessed through DPPH and FRAP antioxidant assays, as well as disk diffusion and MIC methods, against bacterial strains (Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli) and fungal strains (Candida albicans and Aspergillus niger). Computational ADMET profiling evaluated pharmacokinetics and toxicity, while molecular docking assessed interactions with target proteins, including catalase, topoisomerase IV, and CYP51. Results: Theoretical calculations using DFT were in agreement with the experimental results; regarding biological activities, O4 demonstrated the most significant antioxidant activity, with 80.14% DPPH radical scavenging and an IC50 value of 40.91 µg/mL. It exhibited potent antimicrobial activity, surpassing Streptomycin with a 30 mm inhibition zone against Pseudomonas aeruginosa and showing strong efficacy against Staphylococcus aureus and Candida albicans. Computational studies confirmed favorable pharmacokinetic properties, no AMES toxicity, and strong binding affinities. DFT analysis revealed O4’s stability and reactivity, further validating its potential as a therapeutic candidate. Conclusions: This study identified and characterized novel pyrazole derivatives with promising biological and pharmacological properties. O4 emerged as the most potent compound, demonstrating strong antioxidant and antimicrobial activities alongside favorable computational profiles. These findings highlight the potential of the synthetized compounds for therapeutic development and underscore the value of integrating green synthesis with computational techniques in drug discovery. Full article

This paper presents the synthesis and characterization of new thiosemicarbazone derivatives with potential applications as antibacterial, antioxidant and anticancer agents. Six thiosemicarbazone derivatives (L–L5) were synthesized by reacting an appropriate thiosemicarbazide derivative with 2-pyridinecarboxaldehyde. The structures of the obtained compounds were confirmed using mass spectrometry, infrared spectroscopy, and NMR spectroscopy. Antibacterial activity was evaluated by using the microdilution method, determining the minimum inhibitory concentration (MIC) against a panel of Gram-positive and Gram-negative bacteria. Compound L1 showed the most potent antibacterial activity, especially against Bacillus cereus (MIC 10 mg/L). Molecular docking to topoisomerase II and transcriptional regulator PrfA suggests that the studied compounds can effectively bind to molecular targets recognized in anticancer and antibacterial therapies. An assessment of physicochemical properties (ADME) indicates favorable parameters of the compounds as potential drugs. Compounds L and L2 showed the highest antioxidant activity, surpassing the activity of the Trolox standard. Cytotoxicity against A549 lung cancer cells was evaluated by the MTT assay. Compound L4 exhibited the strongest inhibitory effect on cancer cell survival. The obtained results indicate that the synthesized thiosemicarbazide derivatives, especially L1, L2, and L4, are promising compounds with potential applications as antibacterial and anticancer drugs. Full article

Various DNA damage checkpoint control mechanisms in eukaryotic cells help maintain genomic integrity. Among these, NBS1, a key component of the MRE11-RAD50-NBS1 (MRN) complex, is an essential protein involved in the DNA damage response (DDR). In this study, we discovered that DNA damage-binding protein 1 (DDB1) interacts with NBS1. DDB1 is a DDR sensor protein found in UV-induced DNA replication blocks. Through pull-down and immunoprecipitation assays conducted in Xenopus egg extracts and human cell lines, we demonstrated a specific interaction between NBS1 and DDB1. DDB1 was also found to associate with several proteins that interact with NBS1, including DNA topoisomerase 2-binding protein 1 (TopBP1) and Mediator of DNA damage checkpoint protein 1 (MDC1). Notably, the interaction between DDB1 and NBS1 is disrupted in MDC1-depleted egg extracts, indicating that MDC1 is necessary for this interaction. Furthermore, the depletion of DDB1 leads to increased Chk1 activation upon DNA damage. These novel findings regarding the interaction between NBS1 and DDB1 provide new insights into how DDB1 regulates DNA damage pathways. Full article

Dovyalis abyssinica is widely used in Ethiopia for treating various human ailments, yet its pharmacological properties and chemical composition remain largely unexplored. The chromatographic separation of D. abyssinica roots extract afforded five compounds, namely tremulacin (1), cochinchiside A (2), 5-methoxydurmillone (3), catechin-7-O-α-L-rhamnopyranoside (4), and stigmasterol (5), confirmed via IR, NMR, and MS spectral data. This is the first report of these compounds from this plant, except for compounds 1 and 5. The extracts and isolated compounds were tested for antibacterial activity against S. aureus, S. epidermidis, E. faecalis, E. coli, K. pneumoniae, and P. aeruginosa strains. Methanol roots extract exhibited significant antibacterial activity (MIC 0.195 mg/mL) against E. coli and P. aeruginosa. Compounds 1 and 3 showed remarkable antibacterial activity, with compound 1 (MIC 0.625 mg/mL) exhibiting antibacterial activity against S. aureus and S. epidermidis, whereas compound 3 (MIC 0.625 mg/mL) exhibited antibacterial activity against S. epidermidis and K. pneumoniae. Molecular docking analysis revealed better binding energies for compound 1 (−8.0, −9.7, and −8.0 kJ/mol) and compound 3 (−9.0, −8.7, and −8.4 kJ/mol), compared to ciprofloxacin (−8.3, −7.5, and −6.7 kJ/mol), in regard to S. aureus pyruvate kinase, S. epidermidis FtsZ, and K. pneumoniae Topoisomerase IV, respectively. ADME analysis also revealed good antibacterial candidacy of these compounds, provided that in vivo analysis is conducted for further confirmation of the results. Full article

Background/Objectives: Fluoroquinolones (FQs) are topoisomerase II inhibitors with antibacterial activity, repositioned recently as anti-cancer agents. Glutamic acid (GLA) is an amino acid that affects human metabolism. Since an anti-cancer mechanism of FQs is human topoisomerase II inhibition, it is expected that FQ-GLA hybrids can act similarly. Methods: We designed 27 hypothetical hybrids of 6 FQs and GLA through amide bonds at the 3- and 7-position groups of FQs or via ethylenediamine/ethanolamine linkers at the carboxyl group of the FQ. Hydroxamic acid derivatives were also theoretically formulated. Computational methods were used to predict their physicochemical, pharmacokinetic, or toxicological properties and their anti-cancer activity. For comparison, etoposide was used as an anti-cancer agent inhibiting topoisomerase II. Molecular docking assessed whether the hybrids could interact with the human topoisomerase II beta in the same binding site and interaction sites as etoposide. Results: All the hybrids acted as potential topoisomerase II inhibitors, demonstrating possible anti-cancer activity on several cancer cell lines. Among all the proposed hybrids, MF-7-GLA would be the ideal candidate as a lead compound. The hybrid OF-3-EDA-GLA and the hydroxamic acid derivatives also stood out. Conclusions: Both FQs and GLA have advantageous structures for obtaining hybrids with favourable properties. Improvements in the hybrids’ structure could lead to promising results. Full article