Homo- or heterodimeric compounds that affect dimeric protein function through interaction between monomeric moieties and protein subunits can serve as valuable sources of potent and selective drug candidates. Here, we screened an in-house dimeric natural product collection, and panepocyclinol A (PecA) emerged as a selective and potent STAT3 inhibitor with profound anti-tumor efficacy. Through cross-linking C712/C718 residues in separate STAT3 monomers with two distinct Michael receptors, PecA inhibits STAT3 DNA binding affinity and transcription activity. Molecular dynamics simulation reveals the key conformation changes of STAT3 dimers upon the di-covalent binding with PecA that abolishes its DNA interactions. Furthermore, PecA exhibits high efficacy against anaplastic large T cell lymphoma in vitro and in vivo, especially those with constitutively activated STAT3 or STAT3^Y640F. In summary, our study describes a distinct and effective di-covalent modification for the dimeric compound PecA to disrupt STAT3 function.

The development of anticancer drugs to treat triple-negative breast cancer (TNBC) is an ongoing challenge. Immunogenic cell death (ICD) has garnered considerable interest worldwide as a promising synergistic modality for cancer chemoimmunotherapy. However, only few drugs or treatment modalities can trigger an ICD response and none of them exert a considerable clinical effect against TNBC. Therefore, new agents with potentially effective chemoimmunotherapeutic response are required. In this study, five new cyclometalated Ir(III) complexes containing isoquinoline alkaloid C^N ligands were designed and synthesized. Among them, Ir-1 exhibited the highest in vitro cytotoxicity. Mechanistically, Ir-1 could trigger autophagy-dependent ferroptosis and a subsequent ferroptosis-dependent ICD response as well as indoleamine 2,3-dioxygenase (IDO) inhibition via reactive oxygen species (ROS)-mediated endoplasmic reticulum (ER) stress in MDA-MB-231 cells. When immunocompetent BALB/c mice were vaccinated with Ir-1-treated dying TNBC cells, antitumor CD8⁺ T-cell response and Foxp3⁺ T-cell depletion were induced, resulting in long-lasting antitumor immunity in TNBC cells. Moreover, combination therapy with Ir-1 and anti-PD1 could substantially augment in vivo therapeutic effects. Based on these results, Ir-1 is a promising candidate for chemoimmunotherapy against TNBC and its effects are mediated synergistically via ICD induction and IDO blockage.

The p21-activated kinase 4 (PAK4), a key regulator of malignancy, is negatively correlated with immune infiltration and has become an emergent drug target of cancer therapy. Given the lack of high efficacy PAK4 inhibitors, we herein reported the identification of a novel inhibitor 13 bearing a tetrahydrobenzofuro[2,3-c]pyridine tricyclic core and possessing high potency against MIA PaCa-2 and Pan02 cell lines with IC₅₀ values of 0.38 and 0.50 μmol/L, respectively. This compound directly binds to PAK4 in a non-ATP competitive manner. In the mouse Pan02 model, compound 13 exhibited significant tumor growth inhibition at a dose of 100 mg/kg, accompanied by reduced levels of PAK4 and its phosphorylation together with immune infiltration in mice tumor tissue. Overall, compound 13 is a novel allosteric PAK4 inhibitor with a unique tricyclic structural feature and high potency both in vitro and in vivo, thus making it worthy of further exploration.

The transition of cancer cells from epithelial state to mesenchymal state awarded hepatocellular carcinoma (HCC) stem cell properties and induced tumorigenicity, drug resistance, and high recurrence rate. Reversing the mesenchymal state to epithelial state by inducing mesenchymal–epithelial remodeling could inhibit the progression of HCC. Using high-throughput screening, chrysin was selected from natural products to reverse epithelial-mesenchymal transition (EMT) by selectively increasing CDH1 expression. The target identification suggested chrysin exerted its anti-HCC effect through covalently and specifically binding threonine 205 (Thr205) of alpha-enolase (ENO1). For the first time, we revealed that ENO1 bound β-catenin mRNA, and recruited YTHDF2 to identify the m6A modified β-catenin in the 3＇-UTR region to degrade β-catenin mRNA. Eventually, the CDH1 gene expression was improved through the regulation of β-catenin mRNA. ENO1/β-catenin mRNA interaction might be a promising target for cellular plasticity reprogramming. Moreover, chrysin could mediate mesenchymal‒epithelial remodeling through increasing degradation of β-catenin mRNA by promoting the binding of ENO1 and β-catenin mRNA. To the best of our knowledge, chrysin is the first reported small molecule inducing β-catenin mRNA degradation through binding to ENO1. The water-soluble derivative of chrysin may be a natural product-derived lead compound for circumventing metastasis, recurrence, and drug resistance of HCC by mediating mesenchymal‒epithelial remodeling.

Clopidogrel effectively inhibits platelet aggregation in response to ADP by irreversibly binding to the platelet P2Y₁₂ receptor through its active metabolite. However, the observed discrepancies between the pharmacokinetics (PK) and pharmacodynamics (PD) of clopidogrel present substantial challenges in individualizing of antiplatelet therapy. To address these challenges, a robust liquid chromatography–tandem mass spectrometry method has been developed to facilitate the real-time assessment of platelet P2Y₁₂ receptor occupancy. This method has been validated in animal models, providing a reliable link between individual PK profiles and PD effects. Target receptor occupancy offers a comprehensive overview of interindividual variations in clopidogrel metabolism, regulation of P2Y₁₂ receptor expression, and platelet turnover. Moreover, it directly correlates with the inhibitory effect on platelet aggregation. The levels of platelet P2Y₁₂ occupancy accurately reflect the extent of clinical factors influencing the PD of clopidogrel, including dosage, drug–drug interactions (DDI), and type 2 diabetes mellitus (T2DM). As a normalized metric, platelet P2Y₁₂ occupancy not only serves potential as a diagnostic tool for personalized clopidogrel therapy but also aids in elucidating the role of the P2Y₁₂ signaling pathway in cases of abnormal on-treatment platelet reactivity.

MRGPRX2 antagonists possess the potential for the treatment of allergic rhinitis, atopic dermatitis, and chronic urticaria. Previously, we identified a class of diaryl urea (DPU) MRGPRX2 antagonists with sub-micromolar IC₅₀ values in vitro. However, the structure–activity relationship remains unclear. Herein, we adopted a “relative symmetry with electronegativity of different key-groups” strategy for further modification of DPUs to achieve a promising MRGPRX2 antagonist with higher activity and safety. Electrostatic potential energy analysis and biological evaluation revealed that B-1023 and B-5023, that possess relatively symmetric electron-withdrawing substituents, remarkable inhibited mast cell degranulation at a sub-micromolar IC₅₀ in vitro and alleviated anaphylactic symptoms. Furthermore, B-1023, mitigated antigen-induced pulmonary inflammation (AIPI) in mice and competitively bonded to MRGPRX2. In summary, the “relative symmetry with electronegativity of different key-groups” strategy provided a drug design pattern for MRGPRX2 antagonists and identified promising antiallergic precursors for AIPI treatment.

The aryl hydrocarbon receptor (AhR) plays a crucial role in regulating many physiological processes. Activating the AhR–CYP1A1 axis has emerged as a novel therapeutic strategy against various inflammatory diseases. Here, a practical in situ cell-based fluorometric assay was constructed to screen AhR-CYP1A1 axis modulators, via functional sensing of CYP1A1 activities in live cells. Firstly, a cell-permeable, isoform-specific enzyme-activable fluorogenic substrate for CYP1A1 was rationally constructed for in-situ visualizing the dynamic changes of CYP1A1 function in living systems, which was subsequently used for discovering the efficacious modulators of the AhR–CYP1A1 axis. Following screening of a compound library, LAC-7 was identified as an efficacious activator of the AhR–CYP1A1 axis, which dose-dependently up-regulated the expression levels of both CYP1A1 and AhR in multiple cell lines. LAC-7 also suppressed macrophage M1 polarization and reduced the levels of inflammatory factors in LPS-induced bone marrow-derived macrophages. Animal tests showed that LAC-7 could significantly mitigate DSS-induced ulcerative colitis and LPS-induced acute lung injury in mice, and markedly reduced the levels of multiple inflammatory factors. Collectively, an optimized fluorometric cell-based assay was devised for in situ functional imaging of CYP1A1 activities in living systems, which strongly facilitated the discovery of efficacious modulators of the AhR–CYP1A1 axis as novel anti-inflammatory agents.

Ferroptosis has received great attention as an iron-dependent programmed cell death for efficient cancer therapy. However, with the accumulation of iron in tumor cells, the antioxidant system is activated by reducing glutathione (GSH) with glutathione peroxidase 4 (GPX4), which critically limits the ferroptosis therapeutic effect. Herein, an iron and GPX4 silencing siRNA (siGPX4) co-encapsulated ferritin nanocage (HFn@Fe/siGPX4) was developed to enhance ferroptosis by disruption of redox homeostasis and inhibition of antioxidant enzyme synergistically. The siGPX4 were loaded into the nanocages by pre-incubated with iron, which could significantly improve the loading efficiency of the gene drugs when compared with the reported gene drug loading strategy by ferritin nanocages. And more iron was overloaded into the ferritin through the diffusion method. When HFn@Fe/siGPX4 was taken up by human breast cancer cell MCF-7 in a TfR1-mediated pathway, the excess iron ions in the drug delivery system could for one thing induce ferroptosis by the production of reactive oxygen species (ROS), for another promote siGPX4 escaping from the lysosome to exert gene silencing effect more effectively. Both the in vitro and in vivo results demonstrated that HFn@Fe/siGPX4 could significantly inhibit tumor growth by synergistical ferroptosis. Thus, the developed HFn@Fe/siGPX4 afforded a combined ferroptosis strategy for ferroptosis-based antitumor as well as a novel and efficient gene drug delivery system.

Elevated glucose metabolism is a prominent characteristic of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA). However, the efficacy of inhibiting a single target of glucose metabolism in FLS using small molecular inhibitors is limited for RA treatment. Herein, the synergistic inhibition of FLS’ survival, proliferation, and activation by combining two glucose metabolism inhibitors, diclofenac (DC) and lonidamine (LND) was first verified. Subsequently, DC and LND were individually conjugated to cystamine-modified hyaluronic acid (HA) to prepare two polymer-prodrug conjugates. A HAP-1 peptide-modified dual polymer-prodrug conjugates-assembled nanoparticles system (^HAP–1NP_DC+LND) was further tailored in the optimal synergistic ratio for targeted and synergistic metabolic modulation of FLS to alleviate RA symptoms. Upon targeted uptake by FLS in inflamed joints, HAP^–1NP_DC+LND released DC and LND within the intracellular reductive microenvironment, where DC hinders glucose uptake and LND suppresses glycolytic enzymes to eliminate FLS synergistically. Additionally, the secretion of lactic acid and pro-inflammatory factors from FLS were reduced, thereby disrupting the crosstalk between FLS and pro-inflammatory macrophages. Finally, ^HAP–1NP_DC+LND demonstrated promising efficacy in a mouse model of collagen-induced arthritis (CIA). Overall, this research provides valuable insights into novel therapeutic strategies for the safe and effective of treatment RA through targeted and synergistic metabolic modulation of FLS.

Endothelial dysfunction is one of the early triggers of vascular remodeling during pulmonary hypertension (PH) with complex predisposing mechanisms, mainly via an unbalanced generation of vasoactive factors, increased expression of growth factors, prothrombotic elements, and inflammatory markers. Conventional treatment regimens are restricted to a single therapeutic pathway, which usually leads to limited clinical outcomes. Combination therapies targeting multiple cells and several signaling pathways are increasingly adopted in PH treatment. Herein, inspired by the cocrystal pleomorphism theory, we prepared rod-shaped nanococrystals of the endothelin-1 (ET-1) receptor antagonist (bosentan, BST) and the anti-inflammatory drug (andrographolide, AG) for targeting the pulmonary endothelium and alleviating PH. The 525 nm-sized co-delivery system displayed a rod-like morphology, preferentially accumulated in the pulmonary endothelium and alleviated pulmonary artery (PA) remodeling. A three-week treatment with the preparation significantly alleviated the monocrotaline (MCT)- or Sugen 5416/hypoxia (SuHx)-induced PH by reducing the pulmonary artery pressure, increasing the survival rate, improving the hemodynamics, and inhibiting vascular remodeling. Mechanistically, the nanococrystals collaboratively repaired endothelial dysfunction by suppressing the pathways of ET-1/NF-κB/ICAM-1/TNF-α/IL-6. In conclusion, the cocrystal-based strategy offers a promising approach for constructing co-delivery systems. The developed rod-shaped nanococrystals effectively target the pulmonary endothelium and relieve experimental PH.