Search Results (2,615)

Resistance to imatinib remains a therapeutic challenge, largely driven by point mutations within the kinase domain of the BCR-ABL, among which the T315I substitution constitutes the most clinically significant barrier. Ponatinib effectively inhibits this mutant form but is limited by dose-dependent cardiovascular toxicity, prompting efforts to develop safer and more selective agents. Recent advances highlight aminopyrimidine-derived scaffolds and their evolution into thienopyrimidines, oxadiazoles, and pyrazines with improved activity against BCR-ABL^T315I. Further progress has been achieved with benzothiazole–picolinamide hybrids incorporating a urea-based pharmacophore, which benefit from strategic hinge-region substitutions and phenyl linkers that enhance potency. Parallel research into dual-mechanism inhibitors, including Aurora and p38 kinase modulators, demonstrates additional opportunities for overcoming resistance. Combination strategies, such as vorinostat with ponatinib, provide complementary therapeutic avenues. Natural-product-inspired approaches utilizing fungal metabolites provided structurally diverse scaffolds that could engage sterically constrained mutant kinases. Hybrid molecules derived from approved TKIs, including GNF-7, olverembatinib, and HG-7-85-01, exemplify rational design trends that balance efficacy with improved safety. Molecular modeling continues to deepen understanding of ligand engagement within the T315I-mutated active site, supporting the development of next-generation inhibitors. In this review, we summarized recent progress in the design, optimization, and biological evaluation of small molecules targeting the BCR-ABL^T315I mutation. Full article

Panax notoginseng, a high-value medicinal crop, suffers substantial yield losses due to Fusarium oxysporum-mediated root rot, for which no molecularly defined control targets are currently available. Histone acetyltransferases (HATs) serve as crucial epigenetic regulators of fungal development and stress responses; however, their functional roles in F. oxysporum remain largely unexplored. In this study, we systematically identified six FoHAT genes via genome-wide analysis and classified them into evolutionarily conserved subfamilies through phylogenetic comparison with orthologs from Saccharomyces cerevisiae, Homo sapiens, and Arabidopsis thaliana. Structural analyses revealed distinct motif compositions and domain architectures among FoHAT members, while promoter cis-element profiling suggested potential subfunctionalization via stress-responsive regulatory mechanisms. Functional investigations demonstrated that major notoginsenosides present in P. notoginseng root exudates—R₁, Rg₁, Rg₂, Re, and Rd—dynamically influenced both spore germination and FoHAT expression profiles. Intriguingly, each notoginsenoside exerted concentration-dependent non-linear effects on spore germination, either inhibiting or promoting the process. Concurrently, notoginsenoside exposure triggered compensatory transcriptional responses, most notably a rebound in Fo-Hat1_N expression from 9% to 112% under Rd treatment. This work establishes an initial epigenetic framework for combating Fusarium root rot in medicinal plants and offers a foundation for developing HAT-targeted small-molecule inhibitors. Full article

Inflammatory Bowel Diseases (IBD), which include Crohn’s disease (CD) and ulcerative colitis (UC), are chronic, immune-mediated disorders marked by persistent and recurrent inflammation of the gastrointestinal tract. Over the past two decades, major advances in understanding the immunologic and molecular pathways that drive intestinal injury have transformed the therapeutic landscape. This progress has enabled the development of novel biologics and small-molecule agents that more precisely target dysregulated immune responses, thereby improving clinical outcomes and quality of life for many patients. Despite these therapeutic advances, IBD remains a highly heterogeneous condition. Patients differ widely in disease phenotype, progression, and response to specific treatments. Consequently, selecting the most effective therapy for an individual patient requires careful consideration of clinical features, molecular markers, and prior treatment history. The shift toward personalized, prediction-based treatment strategies aims to optimize the timing and choice of therapy, minimize unnecessary exposure to ineffective drugs, and ultimately alter the natural course of disease. In this review, we provide a comprehensive overview of current evidence guiding drug positioning in IBD, with particular emphasis on biologic therapies and small-molecule inhibitors. We also examine emerging biomarkers, clinical predictors of response, and real-world factors that influence therapeutic decision-making. Finally, we discuss the challenges and limitations that continue to hinder widespread implementation of personalized strategies, underscoring the need for further research to integrate precision medicine into routine IBD care. Full article

Overexpression of protein phosphatase 5 (PP5) is implicated in tumor cell growth, establishing PP5 as a compelling target for small-molecule anticancer therapy. Building on prior success in achieving selectivity within the PP2A domain through scaffold functionalization that maximizes active-site interactions, we propose a parallel strategy for PP5 inhibition. Norcantharidin, the demethylated cousin of cantharidin, is a potent yet unselective phosphatase inhibitor, making its bicyclic framework an attractive platform for systematic derivatization. The approach reported herein exploits anhydride reactivity to generate a carboxylic acid derivative that is transformed into a chloromethyl ester. Chloromethyl ester functionality serves as a strategically activated intermediate enabling downstream functional-group diversification under mild, neutral conditions while preserving scaffold integrity. This modular synthetic strategy establishes a foundation for the development of PP5-selective norcantharidin derivatives with improved tumor selectivity, potency, and synthetic feasibility. Full article

Respiratory syncytial virus (RSV) remains a leading cause of lower respiratory tract infections (LRTIs) and infant mortality worldwide. Despite recent advances in prophylactic interventions, effective therapeutics for active RSV infection are still lacking. Small molecule non-nucleoside inhibitors (NNIs) targeting the RSV L protein, particularly its polyribonucleotidyltransferase (PRNTase) domain, represent a promising antiviral strategy. Here, we evaluate the genetic variability of the PRNTase domain and the binding pocket of two NNIs, MRK-1 and MRK-2, to assess the potential for preexisting resistance. A comprehensive analysis of 28,140 RSV L protein sequences from NCBI Virus and GISAID EpiRSV databases revealed low overall variability within the PRNTase domain and near-complete conservation of the MRK-1/2 binding pocket. Resistance-associated mutations identified through in vitro dose-escalation studies localized to this pocket but were absent in global sequence datasets. These findings support the PRNTase domain as a genetically stable and viable target for NNI-based RSV therapeutics and suggest a low likelihood of preexisting resistance among circulating strains. Full article

Nucleoside analogs remain central to the treatment of hematologic malignancies and solid tumors, yet resistance frequently occurs, contributing to relapse and disease-related mortality. Rather than arising from a single mechanism, effective nucleoside analog activity requires successful navigation of multiple biological barriers, including cellular uptake, intracellular activation, nucleotide pool balance, genome surveillance, and mitochondrial stress responses. This review integrates recent advances describing how alterations at each of these levels contribute to resistance to nucleoside analog therapies. We further highlight emerging therapeutic strategies centered on small-molecule inhibitors that exploit these vulnerabilities to enhance the efficacy of nucleoside analogs. Together, this integrative perspective supports the need for development of small molecule inhibitors and design of combination approaches aimed at restoring apoptotic competence and improving the use of nucleoside analog-based therapies for the treatment of cancer. Full article

The SARS-CoV-2 nucleocapsid protein (Np) plays multifunctional roles in the viral life cycle. By interacting with host cellular proteins, Np regulates viral RNA transcription, replication, and immune evasion. It controls genome packaging and counteracts host RNA interference mediated antiviral responses through its RNA binding activity. Previous studies revealed a physical interaction between Np and DDX3X, a human DEAD-box RNA helicase that facilitates the replication of several viruses. This interaction enhances Np affinity for double-stranded RNA and inhibits DDX3X helicase activity. Since Np-RNA binding activity promotes ribonucleoprotein complex formation, targeting this interaction is a promising antiviral strategy. We generated truncated protein variants to define interaction regions between Np and DDX3X. Using AlphaFold modelling, we identified RecA2 as the key DDX3X domain involved in Np binding. Finally, to disrupt Np-RNA complex formation, we screened a small molecule library of putative binders of Np N-terminal region and identified two candidate inhibitors for further development. Full article

Photobiomodulation (PBM) therapy has been effectively used to relieve pain and inflammation and promote tissue healing and regeneration in a broad range of ailments. Prior work has focused on intracellular mitochondrial cytochrome c oxidase, while extracellular latent TGF-β1 activation had been noted. This work investigated the role of PBM-generated redox signaling and integration in normal oral keratinocytes, using Western blots and pathway-specific small molecule inhibitors. We observed that PBM primarily generates ROS intracellularly within mitochondria, which then diffuse extracellularly to activate latent TGF-β1. This activation triggers ATF-4 expression through both canonical (Smad3) and non-canonical (p38, ERK) TGF-β signaling pathways. We observed a critical role for NFκB as an essential integrator, coordinating these responses as evidenced by the loss of ATF-4 expression following NFκB inhibition (BAY II) after both PBM and TGF-β1 treatments. Proteomic pathway analysis revealed that PBM downregulates inflammatory and apoptotic pathways while activating stress-adaptive responses in the NFκB pathway. A core set of PBM-induced redox, NFκB, and TGF-β signaling targets was identified. These findings suggest that optimal PBM treatment responses require a coordinated action of multiple signaling pathways that optimize cellular adaptation to stress and promote tissue repair rather than protracted inflammation and cell death. Full article

Tuberculosis (TB) remains a leading infectious killer, increasingly complicated by multidrug-resistant (MDR) and extensively drug-resistant (XDR) disease; current regimens, although effective, are prolonged, toxic, and often fail to reach intracellular bacilli in heterogeneous lung lesions. This narrative review synthesizes how next-generation antimycobacterial strategies can be translated “from molecule to patient” by coupling potent therapeutics with delivery platforms tailored to the lesion microenvironment. We survey emerging small-molecule classes, including decaprenylphosphoryl-β-D-ribose 2′-epimerase (DprE1) inhibitors, mycobacterial membrane protein large 3 (MmpL3) inhibitors, and respiratory chain blockers, alongside optimized uses of established agents and host-directed therapies (HDTs). These are mapped to inhalable and nanocarrier systems that improve intralesional exposure, macrophage uptake, and targeted release while reducing systemic toxicity. Particular emphasis is placed on pulmonary dry powder inhalers (DPIs) and aerosols for direct lung targeting, stimuli-responsive carriers that trigger release through pH, redox, or enzymatic cues, and long-acting depots or implants that shift daily dosing to monthly or quarterly schedules to enhance adherence, safety, and access. We also outline translational enablers, including model-informed pharmacokinetic/pharmacodynamic (PK/PD) integration, device formulation co-design, manufacturability, regulatory quality frameworks, and patient-centered implementation. Overall, aligning stronger drugs with smart delivery platforms offers a practical pathway to shorter, safer, and more easily completed TB therapy, improving both individual outcomes and public health impact. Full article

Acute kidney injury (AKI) is a critical clinical syndrome characterized by a rapid decline in renal function, frequently resulting from ischemia, nephrotoxicity, or sepsis. It represents a major global health burden due to its high morbidity and mortality and its strong association with progression to chronic kidney disease. In this study, we identified a novel small-molecule TLR4 inhibitor, DB03476, via structure-based virtual screening targeting the intracellular TIR domain of murine Tlr4. Molecular dynamics simulations confirmed that DB03476 stabilizes Tlr4 without altering its global conformation. In a murine ischemia–reperfusion-induced AKI model, DB03476 administration significantly attenuated renal inflammation, macrophage infiltration, and apoptosis and suppressed the TLR4/MyD88/NF-κB pathway. Moreover, DB03476 exhibited cross-species efficacy by binding conserved residues in human TLR4 with high affinity. Functional validation using human kidney organoids confirmed its protective effects against inflammatory challenge. These results demonstrate DB03476 as a promising therapeutic agent for AKI through selective inhibition of TLR4-mediated inflammatory responses. Full article

Background/Objectives: The enhancement of antitumor immune responses by radiotherapy (RT) is partially attributed to the activation of the IFN-type-I pathway. However, the loss of HLA-class-I molecules, which occurs in a large percentage of non-small-cell lung cancers (NSCLCs), may block the cytotoxic effect of T-cells and immunotherapy (IO). Moreover, autophagy is also involved in HLA downregulation. We investigated the complex interactions between RT, HLA molecules, autophagy, and IFN-type-I responses. Methods: The A549, H1299, and ATG7-deficient NSCLC cell lines, along with the modified shLC3A H1299 cell line, were used for in vitro experiments. The effect of RT (8 and 3 × 8 Gy) on Interferon beta (IFNβ), IFN-stimulated genes (ISGs), and HLA-class-I expression in combination with IFN-type-I-response inhibitors (Ruxolitinib, Tofacitinib, Amlexanox) targeting the JAK and TBK1 was studied with Flow cytometry and RT-PCR. Results: RT significantly induced HLA-class-I expression. A parallel upregulation of IFNβ and ISGs mRNA levels was also documented. Although the IFN-type-I-response inhibitors suppressed the RT-induced IFNβ and ISGs expression, their effect on HLA-class-I expression was minimal. Blockage of LC3A autophagy (shLC3A cell line) significantly upregulated HLA-class-I basal levels, and RT further enhanced HLA expression. IFN-type-I-response inhibitors blocked the RT-inductive effect in the shLC3A H1299, but had no effect in the ATG7-deficient H1650 cell line. Conclusions: The current study supports the theory that baseline autophagy, RT-induced autophagy blockage, and IFN-type-I response enhancement define the HLA-class-I levels in NSCLC cells. This complex interplay emerges as a promising target for the development of radio-vaccination strategies to enhance the efficacy of radio-immunotherapy. Full article

Background/Objectives: Approved for treatment of acute leukemia, gemtuzumab ozogamicin (GO) and inotuzumab ozogamicin (InO) are antibody–drug conjugates (ADCs) that deliver a toxic calicheamicin (CLM) derivative. The resistance mechanisms to GO/InO remain incompletely understood. Methods: We performed a genome-wide clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 screen for CLM sensitivity genes, and then performed confirmatory cytotoxicity assays. Results: Several DNA damage pathway regulation genes were identified, most notably TP53. Across 13 acute leukemia cell lines, the six TP53-mutant cell lines (TP53^MUT) were indeed 10- to 1000-fold less sensitive to CLM than the seven TP53^WT cell lines. In five TP53^WT/KO syngeneic cell line pairs we generated, TP53^KO cells were significantly less sensitive to CLM than their TP53^WT counterparts. In TP53^WT but not TP53^MUT cells, the MDM2 inhibitor and p53 activator, idasanutlin, enhanced CLM cytotoxicity, demonstrating that decoupling of cells from MDM2-p53 regulation sensitizes leukemia cells to CLM. The ATM inhibitors AZD1390 and lartesertib also significantly enhanced CLM efficacy but did so independent of the TP53 status. In contrast, neither an ATR inhibitor, Chk1/Chk2 inhibitor, Chk2 inhibitor, or a PARP inhibitor significantly impacted CLM-induced cytotoxicity across the thirteen cell lines. Together, our studies identify ATM, MDM2, and TP53—which are in the same cellular response to DNA damage pathway—as key modulators of CLM-induced cytotoxicity in acute leukemia cells. Conclusions: These results support further evaluation of combination therapies with corresponding small-molecule inhibitors (currently pursued for therapy of other cancers) toward clinical testing as novel strategies to increase the efficacy of CLM-based ADCs such as GO and InO. Full article

Metalloproteinases (MPs) are zinc-dependent endopeptidases, including matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinases (ADAMs), implicated in various diseases such as cancer, neurodegenerative disorders, and cardiovascular conditions. Among MPs, ADAM-17, also known as tumor necrosis factor-α (TNF-α)-converting enzyme (TACE), plays a crucial role in extracellular matrix remodeling and cytokine release. Dysregulation of ADAM-17 contributes to inflammatory diseases, cancer progression, and immune modulation. While small-molecule inhibitors have been limited by off-target effects and instability, antibody-based approaches offer a more selective strategy. Monoclonal antibodies show promise in blocking ADAM-17 activity, but there are concerns about toxicity due to the lack of selectivity. Enhancing the binding affinity and selectivity of single-chain antibodies requires unraveling the structural details that drive MP targeting. This study uses yeast surface display (YSD) and fluorescence-activated cell sorting (FACS) to engineer single-chain variable fragment (scFv) antibodies with optimized complementarity-determining region 3 of the heavy chain (CDR-H3) conformations. Next-generation sequencing (NGS) was used to identify key residues contributing to high-affinity ADAM-17 binding. These findings offer a framework for designing monoclonal antibodies against ADAM-17 and other MPs, paving the way for novel antibody-based designer scaffolds with applications in developing therapeutics. Full article

The renin–angiotensin–aldosterone system (RAAS) is essential for controlling blood pressure and maintaining fluid balance, driving significant structural changes throughout the cardiovascular system, including the heart and blood vessels. As a result, the RAAS is a key therapeutic target for various chronic cardiovascular diseases, ranging from arterial hypertension (AH) to heart failure (HF). In this review, one of our objectives is to describe the new evidence over the last 4 years regarding the RAAS. Moreover, we pay attention to the structure and function of the angiotensin II type 1 receptor (AT1R) and its role in hypertension, as well as define its active site. Later, we discuss the most potent, selective inhibitors of AT1 receptors, based on in vitro and in vivo experiments, from 2020 to 2024. Large peptide molecules, small non-peptide-like molecules, and sartan derivatives are analyzed. The low IC₅₀ values of the entities that do not resemble sartans showcase the vast chemical space that can be explored for the creation of more potent antihypertensive medications. We have also employed computational chemistry tools in order to identify key molecular interactions between the compounds of the literature studied in order to elucidate the underlying reasons why these different molecules exhibit variations in their binding energies and overall potency. Full article