Molecular biomedicine最新文献

Cancer cells rely heavily on de novo pyrimidine synthesis. Inhibiting pyrimidine metabolism directly suppresses tumor growth and fosters immune activation within the tumor microenvironment. Dihydroorotate dehydrogenase (DHODH) is a key enzyme in the de novo pyrimidine synthesis pathway. Inhibiting DHODH can reverse immune suppression and trigger a mild innate immune response. However, the impact of DHODH inhibition on natural killer (NK) cells remains to be explored. In this study, we found that DHODH inhibition promoted NK cell infiltration into tumors efficiently. Mechanistically, DHODH suppression induced mitochondrial oxidative stress, leading to mitochondrial DNA (mtDNA) release into the cytoplasm through voltage-dependent anion channel (VDAC) oligomerization and caspase-3 activation. This subsequently activated the stimulator of interferon gene (STING) pathway, triggered ferroptosis, and induced gasdermin E (GSDME) mediated pyroptosis in cancer cells. These changes collectively facilitated NK cell recruitment. Furthermore, infiltrated NK cells enhanced GSDME-dependent pyroptosis in tumor cells through granzyme release, establishing a positive feedback loop that amplified anti-tumor immunity. Additionally, we developed EA6, a novel DHODH inhibitor that is more effective at promoting NK cell infiltration. In summary, this study reveals that targeting pyrimidine metabolism activates a novel mechanism involving pyroptosis-ferroptosis crosstalk and STING pathway activation to enhance NK cell-mediated immunity. These finding opens new avenues for enhancing the efficacy of targeted nucleotide metabolism in cancer therapy.

Glioblastoma (GBM) is characterized by the highly infiltrative growth of cancer cells into the surrounding brain parenchyma. DnaJ Heat Shock Protein Family (Hsp40) Member C10 (DNAJC10, also known as ERDJ5 and PDIA19), involved in endoplasmic reticulum-associated degradation (ERAD), has been identified as a tumor suppressor in several cancers. However, its precise role and underlying mechanism in GBM remain unclear. We found that DNAJC10 expression is downregulated in GBM patients and correlated with poor survival outcomes. Overexpression of DNAJC10 reduced GBM cell migration and invasion in vitro, while its knockdown promotes these processes. Moreover, DNAJC10 overexpression inhibits infiltrative growth of GBM cells, suppresses tumor propagation and prolongs survival in xenografted mice. Mechanistically, DNAJC10 regulates multiple molecules and pathways involved in cell motility, including the epidermal growth factor receptor (EGFR) pathway. Importantly, DNAJC10 overexpression decreases EGFR transcription by inhibiting spliced X-box binding protein 1 (XBP-1s). DNAJC10 regulates XBP-1s splicing through the inositol-requiring enzyme 1α (IRE1α) branch of the unfolded protein response (UPR). XBP-1s binds the EGFR promoter and enhances recruitment of SET7/9 methyltransferase, H3K4me3, and H3K4me1. Pharmacological inhibition of histone methylation attenuates XBP-1s-induced EGFR transcription, indicating XBP-1s promotes EGFR expression via recruiting SET7/9 for H3K4 methylation. XBP-1s overexpression reverses DNAJC10-mediated EGFR downregulation. Collectively, DNAJC10 suppresses EGFR transcription by inhibiting the UPR IRE1α-XBP-1s axis, reducing SET7/9 recruitment and H3K4 methylation at the EGFR promoter. Targeting DNAJC10 or XBP-1s could be a potential approach for inhibiting GBM infiltration and may represent a novel avenue for GBM treatment.

Osteopontin (OPN) is a multifunctional glycoprotein known to play critical roles in autoimmunity and tissue repair, yet its function in acute viral myocarditis remains poorly understood. To systematically investigate the pathogenesis of viral myocarditis, this study integrated clinical observations from patients with myocarditis and four genetically distinct mouse strains following intraperitoneal inoculation with coxsackievirus B3 (CVB3). Cardiac transcriptomic profiling via RNA-seq uncovered global changes in gene expression, while quantitative RT-PCR and ELISA assays were employed to measure OPN expression levels in cardiac tissues and plasma. A macrophage-specific OPN knockout (OPN^-/-) model was generated by crossing OPN flox/flox mice with Lyz2-Cre transgenic mice. In patients with myocarditis, elevated levels of plasma OPN were observed, suggesting its potential utility as a diagnostic biomarker. In murine models, cardiac OPN expression was significantly upregulated during acute viral myocarditis and exhibited a strong inverse correlation with systolic and diastolic function. Further analyses identified macrophages as the primary cellular source of OPN in the heart. Mechanistically, macrophage-derived OPN was shown to enhance the secretion of IL-12, thereby amplifying the local inflammatory response. Genetic ablation of OPN in macrophages markedly attenuated CVB3-induced cardiac dysfunction and reduced myocardial immune cell infiltration. STAT4 was demonstrated to directly bind to the promoter region of OPN and enhance its expression. Correspondingly, pharmacological inhibition of STAT4 using lisofylline significantly suppressed OPN expression in vivo. In summary, OPN functions as a crucial pro-inflammatory regulator in acute viral myocarditis and represents a promising therapeutic target for mitigating virus-induced cardiac damage.

The WNT signaling pathway, a fundamental molecular network regulating cell proliferation, differentiation, and stemness, plays a critical role in tumorigenesis, cancer progression, and therapeutic resistance. Given its crucial regulatory roles in tumors, WNT signaling pathway has been identified as effective targets for cancer treatment. However, the current clinical efficacy of WNT signaling pathway-targeted anti-tumor therapies remains suboptimal. Based on research investigating the role of WNT signaling pathway in cancer, we systematically discuss the molecular mechanisms of WNT signaling in cancer (including both canonical and non-canonical signaling pathways), the role of WNT signaling in different cancer types, highlighting distinct potential therapeutic approaches targeting WNT signaling. We also comprehensively review innovative strategies targeting WNT signaling, including Porcupine (PORCN) inhibitors, Tankyrase (TNKS) inhibitor, Frizzled (FZD)-targeted monoclonal antibodies, β-catenin/TCF transcriptional complex inhibitors, and natural bioactive compounds and drug repositioning etc., critically evaluating their preclinical efficacy and limitations. We emphasize the need for and challenges in developing WNT-targeted therapies including refining the specificity of WNT signaling pathway-targeted therapies, developing biomarkers for patient selection, and exploring synergies between WNT inhibitors and other therapeutic modalities such as immune checkpoint blockers. These advances aim to enable personalized precision therapy and revolutionize cancer treatment paradigms in the future.

Biliary tract cancer (BTC) is a highly heterogeneous and aggressive gastrointestinal malignancy, marked by a high mortality rate and limited treatment efficacy. The primary contributing factors include the absence of reliable early detection methods, the anatomical intricacy of the biliary system, the inherently aggressive tumor biology, and the restricted effectiveness of systemic therapies. A profound understanding of molecular characteristics and clinically relevant emerging biomarkers is essential for advancing BTC treatment strategies. Recent developments in single-cell multi-omics technologies have enabled the analysis of genetic, transcriptomic, proteomic, and metabolomic data at the single-cell resolution, thereby uncovering the heterogeneity and complexity of tumor biology. These techniques provide critical insights into the diversity of immune cell populations within the tumor microenvironment (TME) and offer novel perspectives on tumor progression and potential therapeutic interventions. While single-cell technologies have significantly advanced the study of solid tumors, their application in BTC remains nascent, with a paucity of comprehensive reviews. This review systematically integrates single-cell genomics, transcriptomics, and epigenomics data to construct a cross-omics molecular atlas of BTC. It highlights the utility of single-cell multi-omics technologies in elucidating tumor heterogeneity, microenvironment remodeling, and clonal evolution in biliary tumors, while thoroughly analyzing their implications for clinical outcomes. Furthermore, this review explores personalized treatment strategies informed by single-cell technologies and underscores the significance of these technologies as indispensable tools for unraveling the complexity of BTC and fostering mechanism-based therapeutic innovation.

Immune evasion in lung cancer is closely associated with the dysregulation of molecular chaperones and immunoregulatory pathways. Heat shock protein 90 (HSP90), which is frequently overexpressed in lung cancer and correlates with poor prognosis, has emerged as a promising therapeutic target. Here, we investigated whether targeting the HSP90-aryl hydrocarbon receptor (AhR) axis with usnic acid (UA) could suppress immune evasion mechanisms in lung cancer. Through target prediction and molecular docking, UA-bead-based proteomic profiling, and in vitro assays, we identified HSP90 as a direct binding of UA. Unlike classical HSP90 inhibitors, UA downregulates HSP90 protein level and disrupts the HSP90-AhR complex, thereby promoting proteasomal degradation of AhR and reducing its half-life. This disruption suppresses AhR-associated gene expression and tryptophan metabolism-related markers under both AhR ligand-bound and ligand-free conditions. Additionally, the immune checkpoint molecules programmed death-ligand 1 (PD-L1) and inducible T-cell costimulator ligand (ICOSL) were markedly downregulated, demonstrating that UA modulates the tumor immune microenvironment via the HSP90-AhR axis. To assess its translational relevance, a water-soluble derivative of UA, potassium usnate (KU), was evaluated in a syngeneic lung cancer mouse model. KU treatment inhibited tumor growth in a dose-dependent manner, reduced tumor-associated macrophages and programmed cell death protein 1 (PD-1⁺) T cells, and increased the infiltration of cytotoxic T lymphocytes (CD8⁺) and helper T cells (CD4⁺). In addition, KU decreased the proliferation marker, antigen Kiel 67 (Ki67⁺), and HSP90⁺ cell populations within tumors. Together, these findings demonstrate that UA/KU targets the HSP90-AhR axis, suppresses immune evasion pathways, and offers a novel immunomodulatory approach for lung cancer therapy.

Despite a substantial reduction in the incidence of coronavirus disease 2019 (COVID-19) infections, severe cases continue to pose a significant clinical burden, particularly among elderly individuals and patients with underlying medical conditions, due to high viral loads and cytokine storm syndrome. Elevated levels of interleukin-6 (IL-6) and tumor necrosis factor (TNF), signaling through their respective receptors, glycoprotein 130 (GP130)/interleukin-6 receptor (IL-6R) and tumor necrosis factor receptor 2 (TNFR2), are independent predictors of disease severity and mortality. To address this challenge, a series of bifunctional and trifunctional decoy receptor fusion proteins were developed by fusing the extracellular domains of TNFR2 and/or GP130 to an engineered angiotensin-converting enzyme 2 (ACE2) protein, the entry receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Five mutations (T27F, K31Y, L79W, R273Q, and N330Y) were introduced into the ACE2 domain to enhance its binding affinity and neutralizing activity against a broad range of SARS-CoV-2 variants, including the currently circulating JN.1 variant. The TNFR2 and GP130 domain confer strong binding to TNF and IL-6R-IL-6 complex, respectively, thereby effectively blocking pro-inflammatory signaling pathways. In a mouse model of acute lung inflammation induced by R848, treatment with the bifunctional and trifunctional fusion proteins markedly attenuated pulmonary pathology by dampening IL-6- and TNF-mediated inflammation. These findings demonstrate a promising therapeutic strategy for severe COVID-19 and offer a framework for designing multifunctional biologics against emerging viral infections.

To survive nutrient stress caused by rapid proliferation and dysfunctional vasculature, tumor cells extensively reprogram their metabolic pathways, including the tricarboxylic acid (TCA) cycle representing a critical remodeling node. Functioning as a key TCA cycle intermediate, malate bridges fumarate and oxaloacetate, both of which are metabolites known to play significant roles in tumorigenesis. However, whether malate itself regulates tumor progression and the specific mechanism remain unclear. In this study, we demonstrate that oral administration of malate significantly inhibits the growth of colorectal cancer (CRC) xenografts in both nude mice and immunocompetent models, suggesting its antitumor effects are immunity-independent. Mechanistically, we found that malate acts as an allosteric regulator of pyruvate kinase M2 (PKM2), binding to it and initiating a cascade that promotes the ubiquitin-mediated proteasomal degradation of cell division cycle 25 A (CDC25A). This reduction in CDC25A enhances the inhibitory phosphorylation of CDK1 at Tyr15, leading to cell cycle arrest and suppression of proliferation. Clinical analyses further support these findings, showing decreased malate levels in human CRC tissues. Moreover, the expression of malate-metabolizing enzymes, MDH1 and FH, is significantly correlated with activity of the CDC25A/p-CDK1 signaling axis. Collectively, our results identify malate as a non-metabolic regulator of the cell cycle, operating through the PKM2-CDC25A-CDK1 pathway, and propose a novel therapeutic strategy targeting metabolic mediators of cell proliferation in cancer.