Acta Pharmaceutica Sinica B

Preclinical evaluation of a novel tetrazine probe within a pretargeted delivery system for theranostics in HER2-positive tumor-bearing mice models

Acta Pharmaceutica Sinica B. 2026, 16(8): 5424-5438.

The approval of radionuclide therapy strategies in nuclear medicine has revolutionized the treatment landscape for patients with advanced malignancies. Due to significant HER2 overexpression in some solid tumors, radionuclide therapy targeting HER2 is a viable strategy. The traditional monoclonal antibody (mAb) direct radiolabelling system may lead to off-target radiation exposure. To address this limitation, we employed the established inverse-electron demand Diels-Alder (IEDDA)-based pretargeting strategy and designed a novel tetrazine probe. First, we identified the optimal targeting molecule (Pertuzumab) and optimal metabolic time (48 h) through micro-positron emission tomography/computed tomography (PET/CT) scans and biodistribution studies of [⁸⁹Zr]Zr-DFO-Per, [⁸⁹Zr]Zr-DFO-Per-F(ab')₂ and [⁸⁹Zr]Zr-DFO-Per-Fab. Next, TCO-Pertuzumab (TCO-Per) was administered to HER2-overexpressing SKOV3 tumor-bearing mice models, and after 48 h of circulation and clearance, a novel radiolabelled small molecule Tz ([¹³¹I]I-Tyr-d-peptide-PEG₁₁-Tz) was introduced. Through a series of in vivo studies, we observed prolonged retention of [¹³¹I]I-Tyr-d-peptide-PEG₁₁-Tz in SKOV3 tumors with rapid renal clearance, along with promising therapeutic efficacy. Our study demonstrates that the novel tetrazine probe within a pretargeting delivery system overcomes limitations of traditional strategies and shows promise for clinical translation.

Targeted nanoparticles with triggered lysosomal escape enable anti-angiogenic immunotherapy for peritoneal metastatic colorectal cancer

Meng Wang, Yutong Qian, Yicong Li, Xicheng Li, Mei Zhu, Danrong Hu, Ran Li, Meng Pan, Yun Yang, Jianan Li, Zhiyong Qian

Acta Pharmaceutica Sinica B. 2026, 16(8): 5452-5470.

Peritoneal metastatic colorectal cancer (PMC) is highly aggressive and resistant to anti-angiogenic monotherapy due to the angiogenesis-immunosuppression vicious cycle. This study develops dual-ligand modified nanoparticles (Reg/DMX@BPF NPs), co-loaded with the angiogenesis inhibitor regorafenib (Reg) and the stimulator of interferon genes (STING) agonist DMXAA (DMX). Reg prevents DMX aggregation as a molecular scaffold via π-π stacking. The folic acid (FA) and phenylboronic acid (PBA)-functionalized BSA (BPF) facilitates active tumor targeting and metastatic site enrichment. Upon internalization into lysosomes, the acidic pH triggers boronate ester bond formation between PBA and glycoproteins, inducing lysosomal disruption and efficient cytosolic release. In addition to STING activation, the BPF potently activates toll-like receptor 4 signaling, synergistically inducing M1 tumor-associated macrophages polarization and dendritic cells maturation. In vivo results demonstrate that Reg/DMX@BPF NPs synergistically inhibit tumor proliferation, normalize pathological vasculature, and reprogram the immunosuppressive microenvironment, which leads to reduced tumor burden and ascites. Collectively, the targeted lysosome-escape nanoparticles provide a novel strategy to overcome the poor efficacy of anti-angiogenic therapy against PMC.

Neutralizing dentin sialophosphoprotein facilitates tumor vascular normalization in colorectal cancer by blocking the crosstalk between tumor cells and endothelial cells

Acta Pharmaceutica Sinica B. 2026, 16(8): 5312-5327.

Irregular, curved, and uneven shapes of tumor vessels contribute to a malignant microenvironment, promoting metastasis. In this study, using patient-derived xenograft models, we observed that tumors derived from metastatic colorectal cancer (CRC) tissues exhibited increased vascular density, hypoxia, and permeability, but reduced perfusion and pericyte coverage, compared with tumors derived from non-metastatic CRC tissues. We conducted a high-throughput microarray analysis to determine the molecular mechanisms underlying compromised vessel structures. Dentin sialophosphoprotein (DSPP) was identified as the most upregulated gene in metastatic CRC with abnormal vasculature. Clinically, high DSPP expression is strongly correlated with poor prognosis and advanced CRC stages. DSPP stimulates tumor vessel abnormalization and CRC metastasis in vivo, and acts as a novel ligand of alpha(v)beta (3) integrin (αvβ3), which is predominantly expressed in tumor vessels. DSPP could directly bind to the peptide segment (amino acids 368-411) of αvβ3 on the cytoplasmic membrane of endothelial cells, activating the mitogen-activated protein kinase signaling pathway. Subsequently, therapeutic targeting of DSPP with human DSPP antibody or TFA, a selective inhibitor of the αvβ3, was investigated to effectively induce tumor vessel normalization and suppress tumor metastasis in mice. Additionally, interleukin-17 F (IL-17F) was identified as an upstream regulator of DSPP expression, which promotes DSPP transcription via p65 binding to its promoter. Therefore, targeting the DSPP/αvβ3 axis to promote tumor vessel normalization and inhibit tumor metastasis represents a new strategy for the clinical implementation of combination targeted therapies in patients with advanced CRC.

Rationale of renewed efforts in developing MC4R modulators to treat metabolic disorders

Acta Pharmaceutica Sinica B. 2026, 16(8): 5016-5033.

The melanocortin-4 receptor (MC4R) is a key regulator of energy balance and a potential target for weight management. Early drug discovery endeavors were hindered by incomplete understanding of its signal transduction mechanisms and broad activation of Gs pathways. Recent advances indicate that MC4R elicits multiple intracellular responses, with Gq/₁₁ signaling in the paraventricular nucleus (PVN) neurons playing a central role in appetite suppression. High-resolution cryo-electron microscopy structures of MC4R, such as the setmelanotide-MC4R-Gq complex reported here, provide valuable insights into ligand binding, receptor activation, and biased signaling, thereby enabling the design of more selective agonists with improved safety profiles. Combination therapies targeting MC4R alongside glucagon-like peptide-1 mimetics and other agents regulating metabolic pathways have shown promise to enhance weight loss. MC4R modulators are also implicated in treating other disorders, including melanocortin signaling dysfunction. These progresses call for renewed efforts in developing the next-generation MC4R-based therapies against metabolic diseases.

A novel small molecule inhibitor targeting KHSRP methylation suppresses colon cancer progression

Shuang Chen, Ningjing Zhang, Yuxiao Zhang, Jiebin Fang, Zhen Tang, Dashan Zhang, Xinyi Tang, Yalin Yu, Mengde Xia, Yan Yi, Wanjing Ding, Zhongjun Ma

Acta Pharmaceutica Sinica B. 2026, 16(8): 5237-5258.

RNA-binding proteins (RBPs) are emerging as crucial regulators in cancer, but the development of therapeutic strategies targeting RBPs remains limited. Here, through chemical proteomics approaches, we identify DIQ01 as a novel small-molecule inhibitor of KH-type splicing regulatory protein (KHSRP), an RBP that is aberrantly hyper-expressed in human tumors and plays an essential role in proliferation, metastasis, and tumor progression. DIQ01 specifically binds to the KH3 and KH4 domains (Phe358 as the key residue) of KHSRP, inhibiting its interaction with mRNAs. Furthermore, the binding of DIQ01 diminishes the PRMT5-mediated arginine methylation of KHSRP, a post-translational modification required for its oncogenic activity. Mechanistically, transcriptomic and proteomic profiling suggested that DIQ01 functionally inactivates KHSRP, triggering destabilization and downregulation of its target PLK1 mRNA. This leads to S-phase arrest, DNA damage, and apoptosis in HCT116 cells. Both in vitro and in vivo studies, including CRC xenograft and patient-derived organoid models, demonstrate that DIQ01 exhibits potent antitumor efficacy with minimal systemic toxicity. Our findings underscore the innovative approach of concurrently targeting the RNA-binding function of an RBP and its post-translational modification, highlighting DIQ01's unique mechanism and significant translational potential as a targeted cancer therapy.

Targeting SIRT6 epigenetically restrains neutrophil hyperplasia and enhances chemotherapeutic efficacy

Acta Pharmaceutica Sinica B. 2026, 16(8): 5259-5275.

Myeloproliferative neoplasms (MPNs) are a group of hematologic malignancies for which current treatment options remain limited, underscoring the urgent need to explore novel therapeutic targets and intervention strategies. Through a high-throughput screen of an epigenetic compound library, we identified the SIRT6 allosteric agonist MDL-800 as a potent suppressor of neutrophil hyperplasia. We established an endogenous sirt6-mutant zebrafish model that develops a myeloproliferative neoplasm (MPN)-like phenotype, with a 64% incidence in adult zebrafish. Mechanistically, Sirt6 was found to regulate neutrophil proliferation in vivo and in vitro by deacetylating histone H3K9 at the c-myb promoter. Sirt6 deficiency led to aberrant proliferation of neutrophils and hematopoietic stem/progenitor cells, whereas Sirt6 overexpression significantly alleviated neutrophil hyperplasia and MPN-related symptoms. Furthermore, the SIRT6 activator MDL-800 enhanced the efficacy of imatinib and reduced neutrophil proliferation in a zebrafish leukemia model. In xenograft mouse models, the combination of MDL-800 and imatinib significantly inhibited leukemia progression and restored drug sensitivity in imatinib-resistant cases. This study establishes the Sirt6-c-Myb axis as a core epigenetic pathway for myeloid homeostasis, providing a novel strategy for simultaneously suppressing neutrophil hyperplasia and enhancing chemotherapeutic efficacy in hematologic malignancies.

Tuning protein corona on nucleic acid nanodrugs for targeted delivery

Acta Pharmaceutica Sinica B. 2026, 16(8): 4876-4897.

Nanoparticle-based delivery systems hold transformative potential for nucleic acid therapeutics. However, the fate of nucleic acid nanodrugs (NANDs) in vivo differs significantly from that observed in vitro, directly impacting their therapeutic efficacy. Upon introduction into biological fluids, NANDs rapidly adsorb proteins onto their surfaces, forming an assembled adsorption layer known as the protein corona (PC). This PC critically influences the physicochemical properties of NANDs and consequently governs their subsequent biological interactions. This review comprehensively introduces the mechanisms underlying PC formation, including dynamic adsorption kinetics and influential physicochemical and environmental factors. We further discuss how the PC modulates key in vivo processes, including penetration of gastrointestinal mucus and epithelial barriers, stability during systemic circulation, biodistribution and cellular tropism, as well as cellular uptake and endolysosome escape of nucleic acid therapeutics. While the PC may obscure engineered ligands and accelerate off-target clearance, it also offers opportunities to harness endogenous proteins for targeting. We therefore highlight emerging design strategies aimed at actively steering PC composition to achieve targeted nucleic acid delivery and enhanced therapeutic outcomes. Finally, we present prospects for translating fundamental knowledge of PC formation and function into the rational design of next-generation engineered nanocarriers for targeted NANDs applications.

Mussel-inspired biphasic microneedle patch for long-acting hypothyroidism treatment

Wen Zhang, Hanqing Liu, Jinxuan Hou, Kai Lei, Jiapeng Lei, Yinli Jin, Chuang Chen, Jianying Huang, Wei Li

Acta Pharmaceutica Sinica B. 2026, 16(8): 5439-5451.

Hypothyroidism, caused by insufficient thyroid hormone production or impaired responsiveness, is typically managed with lifelong daily oral levothyroxine sodium (LT₄). However, oral administration often suffers from variable gastrointestinal absorption and poor adherence. Here, we report a mussel-inspired biphasic microneedle (MN) patch integrating LT₄ microcrystals and a bioadhesive PDA-PAM hydrogel backing for sustained and patient-friendly hypothyroidism management. The biphasic MNs, composed of rapidly dissolving PVA/sucrose tips and a robust polystyrene base, efficiently deposit LT₄ microcrystals intradermally upon insertion, enabling gradual dissolution and sustained release. The hydrogel backing offered strong and flexible adhesion, ensuring reliable skin attachment during movement. In vitro, the patches exhibited first-order LT₄ release for 9 days. In hypothyroid rats, a single patch application maintained therapeutic plasma LT₄ concentrations for ∼6 days, with bioavailability comparable to intravenous injection. In a preliminary study in healthy volunteers (n= 13), placebo MN patches demonstrated high insertion efficiency, good short-term tolerability, and favorable user acceptability. While further studies are required to establish long-term safety and efficacy in patients with hypothyroidism, these findings support the feasibility of a minimally invasive, extended-interval LT₄ delivery strategy.

Cytoplasmic relocation of nuclear Ku70 by Bruceine A augments cGAS-STING pathway-mediated anti-tumor immunity

Acta Pharmaceutica Sinica B. 2026, 16(8): 5200-5216.

DNA-damaging agents combined with agonists of the cGAS-STING pathway can effectively suppress colorectal cancer (CRC) by inducing cancer cell death and eliciting an antitumor immune response. In this study, we demonstrate that the natural compound Bruceine A (BA) inhibits CRC progression through a dual mechanism involving nuclear-to-cytoplasmic translocation of Ku70. Cytoplasmic Ku70 loses its canonical DNA repair function while simultaneously enhancing its interaction with cGAS, leading to increased cGAS oligomerization and elevated levels of double-stranded DNA (dsDNA), both of which amplify cGAS-STING signaling. Furthermore, Bruceine A-mediated Ku70 translocation exacerbates DNA damage accumulation, further enhancing tumor immunogenicity. In the murine CRC model, Bruceine A significantly inhibited tumor growth and enhanced tumor sensitivity to chemotherapy, radiotherapy, and anti-PD-1 treatment. Notably, genetic ablation of STING and CD8⁺ T cells in mice substantially abolished the antitumor effects of Bruceine A, confirming its reliance on cGAS-STING activation and adaptive immunity. Our findings establish Ku70 as a novel therapeutic target in CRC, where its subcellular redistribution disrupts genomic stability and bridges innate immune activation, synergistically promoting tumor cell death and antitumor immunity. Modulating Ku70 localization thus represents a promising strategy to enhance CRC treatment.

Expansion and functional diversification of terpene synthases shape volatile terpenoid landscape in Cannabis sativa

Acta Pharmaceutica Sinica B. 2026, 16(8): 5487-5503.

Terpenoids are key specialized metabolites in Cannabis sativa, shaping cultivar-specific aromas and potentially modulating cannabinoid effects. This study provided a comprehensive analysis of the terpene synthase (TPS) gene family in C. sativa, integrating haplotype-resolved genomic data, volatile terpene profiling, transcriptomics, and functional assays. The comprehensive volatile terpene profiling across 28 spatiotemporal samples spanning weekly developmental intervals and distinct maturity stages from six cultivars identified 227 cannabis volatile terpenes, including 88 monoterpenes and 139 sesquiterpenes, exhibiting distinct tissue, developmental stage, and cultivar-specific patterns. Comparative expression and co-expression network analysis revealed coordinated regulation between MEP/MVA pathways, TPS, and cannabinoid genes, underscoring a shared metabolic foundation. Genome annotation identified 41 full-length CsTPSDK genes, exhibiting extensive expansion and subfamily-specific clusters with structural divergence between haplotypes. Transcript profiling across developmental stages and cultivars distinguished a core set of highly expressed inflorescence-associated CsTPSs from genes exhibiting cultivar-specific regulation. Functional characterization of six previously unreported CsTPSDKs uncovered diverse mono- and sesquiterpene synthase activities, including unexpected substrate promiscuity across subfamilies. These findings deliver the most comprehensive functional annotation of the C. sativa TPS repertoire to date, elucidating the genetic and biochemical bases of terpene diversity and providing a foundation for targeted metabolic engineering and cultivar improvement.