Protein arginine methyltransferase 5 (PRMT5) is overexpressed in many cancers and correlates with poor patient survival. In prostate cancer, PRMT5 cooperates with its cofactor pICln to promote tumour growth by epigenetically activating androgen receptor (AR) expression. Using a near-atomic cryo-EM structure of PRMT5/MEP50/pICln complex, we identified a previously undefined, pICln-specific protein-protein interaction (PPI) interface on PRMT5, termed P4I. Structure-based virtual screening identified the FDA-approved compound etravirine as a binder to this site. BiFC, Co-IP, and PLA assays confirmed that etravirine disrupts PRMT5/pICln interaction. A cryo-EM structure of PRMT5/MEP50/etravirine further validated on-target binding at P4I. Functionally, etravirine reduced prostate cancer cell proliferation, inhibited tumour growth, and downregulated AR and AR-V7 expression in cells and in mouse models. These results demonstrate that the unique P4I interface is a promising therapeutic target and that etravirine serves as a proof-of-concept lead compound for exploring the potential of P4I-targeted strategies in prostate cancer.
In this study, we describe the design of peptide aptamers to modulate interactions between CD2 and CD58 (co-stimulatory molecules) in the immune response. We designed peptide aptamers based on the sunflower trypsin inhibitor-1 (SFTI-1) template, incorporating functional groups that confer conformational stability and aqueous solubility. To address the challenges posed by conformational isomerism in the sunflower trypsin inhibitor template due to proline-proline sequences in peptide design, we developed two aptamer peptides, SFTI-FGUA and SFTI-DMY, incorporating specific functional groups. SFTI-FGUA features a side-chain guanidine group on phenylalanine, while SFTI-DMY features a dimethyl group at the meta position relative to tyrosine’s hydroxyl group. These bulky substitutions on the phenyl ring effectively restrict conformational flexibility and enhance solubility. Evaluation of these peptides using cell adhesion inhibition assays revealed that both aptamer peptides not only exhibited significant inhibition of cell adhesion but also exhibited a predominant conformation in solution. Furthermore, these peptides exhibited stability against enzymatic degradation.
A novel class of 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-pyrazolo[3,4-b]pyrazine derivatives was designed and synthesized as tubulin polymerization disruptors. Among them, compound 10t emerged as the most potent agent, exhibiting IC₅。 values of 0.13-0.18 µM against HeLa, SGC‑7901, and MCF‑7 cancer cell lines. Functional studies revealed that 10t effectively inhibits tubulin assembly in vitro, destabilizes cellular microtubule networks, induces G₂/M cell‑cycle arrest, and triggers apoptosis. Molecular docking indicated that 10t binds to the colchicine site on tubulin, forming a unique hydrogen bond with β‑Asn349 that is not observed with the reference compound CA‑4. Importantly, 10t showed significantly lower cytotoxicity toward normal HUVECs than CA‑4, suggesting an improved safety profile. Collectively, these findings establish the pyrazolo[3,4‑b]pyrazine scaffold as a promising platform for microtubule‑targeting anticancer agents and identify 10t as a compelling lead for further development.
Microtubules assembled from α/β-tubulin heterodimers are critical for cell division and well-established anticancer drug targets, making tubulin polymerization inhibitors a viable route for new chemotherapeutics. Guided by structural analysis of colchicine-site binders and tubulin-ligand computational simulations, we rationally designed and synthesized a series of 6-aryl-1-(3,4,5-trimethoxyphenyl)-1H-pyrazolo[3,4-d]pyrimidines as novel colchicine-binding site tubulin inhibitors. Derivative 9t displayed the strongest antiproliferative potency, with IC₅。 values of 0.065-0.096 μM across tested cancer lines. It exerted minimal toxicity to normal L929 fibroblasts, yielding a selectivity index over 300. Mechanistic assays confirmed 9t suppresses cell-free tubulin polymerization, destroys cellular microtubule architecture, induces persistent G₂/M cell cycle arrest, and activates cancer cell apoptosis. Overall, 9t serves as a promising dual-function tubulin inhibitor with both cytostatic and cytotoxic anticancer effects, meriting further preclinical investigation.
Aurora-A is a potential therapeutic target in prostate cancer. In this study, virtual screening identified four Aurora-A-targeting peptides, among which Peptide-1 showed the most favourable profile. Molecular docking and MST assays demonstrated that Peptide-1 had the lowest predicted binding free energy and the strongest binding affinity towards Aurora-A (Kd = 0.72 ± 0.04 μM). MD simulation, MM/PBSA, and free-energy landscape analyses indicated that the Aurora-A-Peptide-1 complex was conformationally stable and mainly driven by electrostatic interactions. MTT assays showed that Peptide-1 inhibited the proliferation of PC3, DU145, and NCI-H660 cells, with weaker activity in RWPE-1 cells. Aurora-A knockdown reduced cellular sensitivity to Peptide-1, supporting its target-dependent activity. qRT-PCR further showed increased p53 and p21 mRNA expression after Peptide-1 treatment in PC3/p53WT cells. These findings suggest that Peptide-1 may act as an Aurora-A-targeting peptide with antiproliferative activity in prostate cancer cells.
Glucagon-like peptide-1 receptor (GLP-1R) ligands including semaglutide play an important role in drug discovery. Herein, a short semaglutide-derived GLP-1R-engaging segment was used as the basis for scaffold construction, and conformational restabilisation was introduced through lactam stapling and bulky aromatic non-natural amino acid substitution. A total of 108 stapled peptide candidates were designed by structure-guided modelling and virtual screening. Among them, 35 peptides were synthesised and characterised. Most stapled analogues showed improved serum and proteolytic stability relative to semaglutide, and 11CP-17B, 11CP-17N, and 11CP-19N showed the most favourable stability profiles. Molecular dynamics simulations and MM-GBSA analysis were consistent with receptor-compatible poses and favourable predicted interaction patterns for these representative analogues. Collectively, these results define a practical strategy for constructing stabilised semaglutide-derived peptide scaffolds and provide a basis for subsequent functional optimisation of GLP-1R-targeting peptides.
The acidic tumour microenvironment (pHe 6.5-6.9) is sustained by the Warburg effect and pH regulators, such as monocarboxylate transporters 1 and 4, Na+/H + exchanger 1, vacuolar ATPase, and carbonic anhydrases IX and XII. This environment facilitates tumour invasion, immune evasion, and resistance to therapy in solid tumours. Recent advancements in small molecule inhibitors targeting these pathways have demonstrated potential in molecular design, mechanisms of action, and preclinical studies. However, practical applications face challenges, including metabolic compensation, insufficient target selectivity, and clinical translation difficulties. This article reviews the structural design, structure-activity relationships, biological activity, and clinical trial progress of small molecule inhibitors. It also summarises acid-targeted delivery strategies, such as pH-responsive prodrugs and pHLIP peptides. The aim is to highlight the opportunities and challenges in acid-base regulation within the tumour microenvironment and offer insights for developing a new generation of antitumor drugs with high selectivity and low toxicity.
Proteolysis-targeting chimaeras (PROTACs) couple target recognition to ubiquitin-dependent degradation, but their translation requires coordinated optimisation of degradation efficiency and developability. This review frames PROTAC design as a context-dependent medicinal chemistry problem rather than modular assembly of a warhead, linker and ubiquitin ligase (E3) recruiter. Linker length, rigidity, and exit vectors, together with warhead recognition topology, determine whether binary binding can form a cooperative, ubiquitination-competent ternary complex. Warhead binding mode further affects catalytic turnover and cellular degradation. Linker-free designs and disclosed clinical PROTAC structures show that beyond Rule of Five property control remains central to exposure. Conditional linkers and E3 ligase choice add biological constraints through stimulus-responsive activation, recruiter tractability, E3 expression, localisation, pathway biology, and safety liabilities. This review integrates these principles into a framework for PROTAC design. The framework aligns productive ternary complex assembly, effective exposure and biological-context compatibility within the intended therapeutic context.
Cathepsin K (CatK), a promising therapeutic target for bone-related diseases, uniquely unfolds triple-helical collagen and digests tropocollagen into soluble peptides in the presence of chondroitin 4-sulphate (C4-S). However, the molecular mechanism of CatK-mediated collagenolysis remains poorly understood, hindering the rational design of selective inhibitors. In this study, we performed microsecond-scale molecular dynamics simulations of a fully solvated ternary complex comprising the CatK dimer, tropocollagen segment, and C4-S, to indicate the structural and dynamical basis of tropocollagen unwinding. The process was initiated by the progressive disruption of six key inter-chain hydrogen bonds within the tropocollagen. C4-S adopted a cosine-like conformation that bridged CatK and tropocollagen, thereby stabilising the ternary complex. Unwinding occurred at the active site cleft, with Cys25 and Trp184 serving as critical residues that may contribute hydrogen bond disruption and substrate stabilisation. Our findings provided mechanistic insights into CatK-dependent collagen degradation and rational development of next-generation CatK inhibitors.
Candida auris is a major public health concern worldwide due to its efficient transmission, environmental persistence, and broad resistance to approved antifungal classes. This review consolidates recent pharmacological developments in this regard, focusing on mechanistic insights and late-stage therapeutics. Novel agents demonstrate activity against multidrug- and pan-resistant isolates via distinct mechanisms of action and enhanced specific binding to CYP51. Repositioned drugs, host-defense peptides, and quorum-sensing modulators also expand the treatable spectrum, particularly for biofilm-associated and device-related infections. Concurrently, artificial intelligence (AI)-guided discovery, nanocarrier-enabled delivery, and multi-omics profiling are greatly accelerating target identification and enhancing the drug metabolism of small-molecule fragments. The emerging combined approaches mark a transition towards mechanism-based antifungal development to combat the increasing clinical burden posed by C. auris. Ongoing integration of precision diagnostics, pharmacodynamic optimization, and novel discovery platforms will be key to translating these advances into durable, real-world therapeutic solutions.
Trichodermin, a sesquiterpene antibiotic from Trichoderma species, shows anticancer potential. In this study, anti-glioblastoma activity was evaluated by (3-(4,5-di methyl thiazol-2-yl)-2,5-diphenyltetrazolium bromide) (MTT) assay, colony formation, lactate dehydrogenase (LDH) release assay, flow cytometry, wound-healing, transwell invasion, adhesion, Western blot, combination-index analysis, and an orthotopic luciferase glioblastoma mouse model. Trichodermin reduced viability and clonogenicity and increased LDH release of T98G and A172 cells. Trichodermin induced G2/M arrest with p53 activation and downregulation of cyclin B, cyclin A, and cyclin-dependent kinase 1 (CDK1). In addition, trichodermin induced caspase-dependent apoptosis. Invasion, wound healing, and adhesion were suppressed with modulation of epithelial-mesenchymal transition (EMT)-related proteins. Combination index analysis demonstrated a synergistic interaction between trichodermin and temozolomide, possibly due to increased apoptosis. In the mouse model, intraperitoneal trichodermin inhibited intracranial tumour growth and prolonged survival, and increased cleaved caspase-3 expression in tumour tissues. These findings indicate that trichodermin exerts anti-glioblastoma activity and warrants further preclinical evaluation as a potential adjunct to temozolomide therapy.
In 2025, the FDA approved 46 drug marketing applications, 31 of which were small molecule drugs. Despite the advancements in biotechnologies such as antibody drugs, RNA-based treatments, and antibody-drug conjugates, small molecule drugs remain dominant in new drug discovery. With progress in computer-aided drug design and scaffold-based drug design etc, modern drug discovery has stepped into a phase of rapid development. The marketed drugs in the same field often share similar structures and biological activities, while development of me-too drugs can notably enhance potency and streamline the development process. Comprehending the development process of newly launched drugs helps to identify mainstream technologies and provides structural scaffolds and inspirations for future research. This review comprehensively summarises the development progress of new drugs approved in 2025, including molecular design, structural modification, structure-activity relationship, and enhancement of drug-like properties to offer valuable insights to pharmaceutical chemists and bring inspiration for future research.
Protein prenylation is a critical post-translational modification that controls many cancer-related signalling pathways and represents an important therapeutic target currently lacking effective pharmacological agents. Here, we establish the fluorescent prenyl diphosphate analogue MANT-O-GPP as a multipurpose probe for simultaneous analysis of ligand binding and catalysis in geranylgeranyltransferase I (GGTaseI) and farnesyltransferase (FTase). Using a tryptophan-to-MANT-O-GPP FRET assay, we found that MANT-O-GPP bound to GGTaseI and FTase with high affinity and reported occupancy of the isoprenoid donor site, as confirmed by displacement with the native substrates. In parallel, a FRET-based activity assay employing CFP-tagged protein substrates enabled direct monitoring of prenyl transfer and product formation. Notably, the known inhibitor L-778123 blocked catalysis without displacing MANT-O-GPP, demonstrating that the combined platform distinguishes prenyl-site competitors from inhibitors acting through the adjacent protein-substrate region. This fluorescence-based system provides a practical, mechanistically informative, and high-throughput-compatible platform for prenyltransferase inhibitor discovery.
cGAMP-induced STING activation contributes to inflammatory and interferon-related signalling, making STING a relevant target for inhibitor development. In this study, a 59,319-sequence peptide library was screened against STING by molecular docking, and four top-ranked peptides were selected for evaluation. MST analysis demonstrated that Peptides 1-4 bound to recombinant STING, with Peptide-1 showing the highest affinity (Kd = 0.15 ± 0.01 μM). Docking and simulation analyses suggested that binding was mediated by hydrogen bonding and hydrophobic contacts. Molecular dynamics, MM/PBSA, and free energy landscape analyses suggested stable binding with favourable calculated energetics. Peptide-1 showed no apparent cytotoxicity up to 10 μM in RAW264.7 macrophages and primary BMDMs, while dose-dependently reducing cGAMP-induced IFN-β and IL-6 expression at both protein and mRNA levels. This inhibitory effect was accompanied by reduced STING and IRF3 phosphorylation. Collectively, these findings suggest that Peptide-1 may bind STING and attenuate cGAMP-induced IFN-β and IL-6 expression.
EGFR L858R is an activating mutation associated with aberrant EGFR signalling, and molecules capable of recognising this mutant remain of research interest. In this study, a virtual peptide library containing 59 319 heptapeptides was screened against the EGFR L858R crystal structure, leading to the identification of four peptides with favourable predicted binding ability. Among them, Peptide-1 showed the strongest binding affinity in MST assays (Kd = 0.35 ± 0.02 μM), with higher affinity than the reference peptide DTP-1. Integrated structural and dynamic analyses showed that Peptide-1 could form a relatively stable binding conformation with EGFR L858R. Peptide-1 reduced the viability of SKOV3, OVCAR3, and CaOV3 cells, showed weaker effects on IOSE-80 cells, and its activity was markedly attenuated after EGFR-targeting shRNA transduction. In addition, Peptide-1 decreased Cyclin D1 mRNA expression and increased Caspase-3 mRNA expression. These findings indicate that Peptide-1 can be further investigated as an EGFR L858R-targeting peptide.
PDE5 is a subfamily member of the phosphodiesterase (PDE) superfamily. It is encoded by a single PDE5A gene, and its primary function is to specifically hydrolyse cyclic guanosine monophosphate. To date, a few inhibitors targeting PDE5, exemplified by sildenafil, tadalafil, and vardenafil, have been approved for the treatment of several diseases including pulmonary arterial hypertension and erectile dysfunction. However, due to their low subtype selectivity, the currently marketed PDE5 inhibitors cause some severe adverse effects in clinical applications, including headaches and visual disturbances. Therefore, discovering new PDE5 inhibitors featuring novel scaffolds and high subtype selectivity for disease treatment and target research remains to attract significant interest from both academics and industry. This review emphasises the rational design, advantages, and potential limitations of PDE5 inhibitors with diverse scaffolds, aiming to generate insights into the discovery and development of novel subtype-selective PDE5 inhibitors.
The tumour necrosis factor receptor superfamily (TNFRSF) represents a pivotal signalling network that orchestrates immune homeostasis and regulates cell fate decisions. Lymphotoxin β receptor (LTβR, TNFRSF3), a key TNFRSF member, is predominantly expressed on stromal cells and distinct myeloid subsets. Upon binding to its ligands lymphotoxin α1β2 (LTα1β2) and TNFSF14 (LIGHT), LTβR activates multiple signalling cascades, including canonical and non-canonical NF-κB pathways, thereby playing an essential role in tumour immune regulation. LTβR exerts multifaceted functions in lymphoid organogenesis, chronic inflammation, and tumour microenvironment (TME) remodelling. Notably, it promotes the formation of high endothelial venules and tertiary lymphoid structures, facilitating immune cell recruitment and spatial organisation to shape anti-tumour immunity. Recent studies highlight that LTβR agonists show promising therapeutic potential, particularly in combination with immune checkpoint blockade. This review summarises the biological features of LTβR and its dual regulatory roles in the TME, underscoring its potential as a novel target for cancer immunotherapy.
Inflammation is a finely tuned host defense mechanism whose perpetual activation is a driver, promoter, and supporter of carcinogenesis. Key mediators of chronic inflammatory processes, viz. NF-kB, JAK-STAT, inflammasomes, reactive oxygen species (ROS), and cytokine network, if left unanswered, foster the tumour-supportive environment. Within the tumour microenvironment (TME), inflammatory cells, in combination with stromal and cancerous cells, modulate these pathways and regulate critical tumour hallmarks. Therefore, efforts have been made to understand and tackle the interface between the inflammation-cancer axis, but therapeutic outcomes remain limited. In this context, integrating systems-level biological insights with precision-driven medicinal chemistry may pave the way towards next-generation anti-inflammatory chemotherapeutics. The current review underlines the critical involvement of inflammation in cancer development by providing a comprehensive overview of key molecular pathways. A special emphasis was placed on understanding the medicinal chemistry campaign over the last 5 years for the development of inflammation-targeting small-molecule therapeutics in cancer.
Macrophages are plastic innate immune cells that polarize into pro-inflammatory M1 or anti-inflammatory M2 phenotypes in response to microenvironmental signals, with their dynamic balance governing inflammation resolution and tissue homeostasis. This polarization entails profound metabolic reprogramming, wherein ATP-citrate lyase (ACLY) acts as a key regulator. By controlling intracellular acetyl-CoA production, ACLY modulates histone acetylation and chromatin remodeling, thereby influencing the expression of inflammation-related genes. This review systematically outlines ACLY’s structural features and elucidates its core mechanisms that integrate metabolic and epigenetic cues to orchestrate macrophage polarization and inflammatory responses. In addition, it summarizes the pharmacological properties and clinical translational potential of ACLY inhibitors, highlighting their promise as therapeutic agents. Collectively, this work aims to offer novel theoretical insights and intervention strategies for targeting macrophage immunometabolism in chronic inflammation and associated metabolic disorders.
To combat antimicrobial resistance (AMR), a novel series of pyrrolo[3,2-f]quinazoline-diamine (PQD) derivatives (5a-5z) featuring a flexible benzyl-oxo-benzyl side chain were designed and synthesised via structural optimisation of lead compound IRS-16. All compounds exhibited potent dihydrofolate reductase (DHFR) inhibition. Compound 5a was most notable, showing exceptional enzymatic inhibition (IC50 = 0.92 nM), surpassing both IRS-16 and trimethoprim. 5a demonstrated broad-spectrum antibacterial activity against Gram-positive (e.g., E. faecalis) and Gram-negative strains (e.g., E. coli), as well as clinical isolates of S. aureus, K. pneumoniae, and uropathogenic E. coli (UPEC), with MIC values as low as 0.5 μg/mL. It displayed rapid bactericidal action, low resistance propensity, and inhibited biofilm formation by >90% at 0.5 μg/mL. Additional mechanisms included disruption of bacterial membrane integrity, causing leakage of cellular contents. These results identify 5a as a promising lead for developing novel, broad-spectrum DHFR inhibitors with a low resistance risk.
