Cancer metastasis is a significant contributor to global morbidity and mortality rates. The urokinase type plasminogen activator (uPA) and its receptor (uPAR) play an essential role in facilitating abnormal cell metastasis and tumor progression. This research examines novel uPA/uPAR compounds as potential anticancer targets in various types of tumors. Several compounds were screened for their bioactivity and inhibitory effects on uPA and its receptor interactions, demonstrating the significant potential of a compound previously recognized as a promising uPA inhibitor, initially developed for the treatment of multiple sclerosis. The compounds exhibited notably low IC50 values, as low as 1.4 μM, against the aggressive triple negative breast cancer cell line MDA-MB-231 compared to the chemotherapeutic drug Mitoxantrone. MDA-MB-231 cells treated with KCO241 and KCO246 exhibited selective anticancer activity, inducing apoptotic pathways and demonstrating selective anticancer efficacy. This study showed that these novel uPA inhibitors have potential therapeutic applications for the treatment of metastatic cancers and the modulation of disease progression. Subsequent preclinical in vivo investigations will further evaluate the safety as well as pharmacological characteristics and potential for translation.

The soluble urokinase-type plasminogen activator receptor (suPAR) is a biologic marker of systemic immune activation and fibrotic burden in chronic inflammatory disorders. Recent studies have shown that suPAR has shown potential to distinguish autoimmune liver diseases (AILD) from other liver disorders, and is associated with non-invasive fibrosis indices and immunologic activity. This commentary outlines the evidence for analytical, clinical, and translational potential of suPAR in patients with AILDs. The assay variability and differentiation between liver and systemic inflammation are discussed. Recommendations are made for the establishment of standardized cutoffs for suPAR in diverse populations. Gaps that exist in the current literature regarding suPAR include a lack of histological verification, no long-term data, and no stratification of AILD subtypes. A four-phase innovation model is presented that emphasizes analytic standardization, composite biomarker models, trajectory-based tracking, and equitable global application of suPAR testing. Collectively, these considerations support suPAR as a potential adjunct biomarker with translational relevance in hepatology and immunology, warranting further validation before broader clinical adoption.

This study introduces a novel computational model that integrates cancer stem cells (CSCs) and the plasminogen activation system, filling a crucial gap in cancer research. While theoretical models have separately explored CSCs and the plasminogen activation system, no prior computational framework has combined these elements. Our model focuses on the invasion dynamics of CSCs, emphasizing the critical interactions between urokinase plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1). We employed reaction-diffusion equations and analyzed the determinant and eigenvalue spectra of the Jacobian matrix of the system to identify instability regions within tumors. The findings revealed that the production and binding of uPA and PAI-1 significantly enhance the invasiveness and motility of CSCs, resulting in more complex and aggressive tumor structures. Our study advances the theoretical understanding of cancer dynamics by integrating these two critical biological processes into a single computational framework. This work builds upon and extends previous models by offering a more comprehensive analysis of tumor growth, with significant implications for optimizing cancer treatment strategies. The insights of the model into the interplay between CSCs and the plasminogen activation system offer a valuable tool for both research and potential clinical applications, paving the way for more targeted and effective therapeutic approaches.

PDT02, a peptide identified by phage display and subsequent amino acid optimization, was synthesized via solid-phase peptide synthesis and radiolabeled with gallium-68 to generate [68]Ga-PDT02 for imaging urokinase-type plasminogen activator receptor (uPAR). [68]Ga-PDT02 exhibited high radiochemical purity and moderate binding affinity to uPAR (KD = 531.3 nM). In vitro assays showed markedly higher uptake in uPAR-positive MKN45-huPAR cells than in A549 cells, indicative of receptor-mediated binding. In vivo PET imaging in MKN45-huPAR xenograft-bearing mice demonstrated specific tumor accumulation with a mean uptake of 2.88%ID/mL at 30 min post-injection, followed by rapid clearance from non-target tissues. Biodistribution confirmed rapid renal excretion and low retention in blood, yielding favorable tumor-to-background contrast. Collectively, these results highlight [68]Ga-PDT02 as a promising uPAR-targeted PET radiotracer with favorable pharmacokinetics and imaging performance, supporting its potential utility for non-invasive visualization of uPAR expression in aggressive tumors.

Thrombolytic therapy, exemplified by tissue plasminogen activator, is often constrained by a short half-life, non-specific activity, and bleeding risks. To address these limitations, we developed tLipo@UA, a fibrin-targeted and pH-responsive liposomal system for the co-delivery of the urokinase-type plasminogen activator (uPA) and aspirin (acetylsalicylic acid, ASA). This system was functionalized with the CREKA (Cys-Arg-Glu-Lys-Ala) peptide for specific thrombus homing, and cholesteryl hemisuccinate (CHEMS) was incorporated to enable pH-sensitive drug release within the acidic thrombotic microenvironment. Experiments conducted both in vitro and in vivo demonstrated that tLipo@UA achieved efficient thrombus targeting and responsive drug release. The released uPA effectively dissolved thrombi, while the co-delivered ASA modulated the thrombotic microenvironment by suppressing the inflammatory cytokine release, thereby exhibiting synergistic thrombolytic and anti-inflammatory effects. Encapsulation of uPA significantly prolonged its circulation time and enhanced its localized efficacy. Furthermore, this system showed a favorable biosafety profile. Collectively, tLipo@UA presents a promising strategy for enhancing thrombolytic potency and achieving microenvironment reprogramming with reduced off-target risks, offering a rational design for dual-function drug carriers in the treatment of thrombotic diseases.

The urokinase-type plasminogen activator receptor (uPAR) is a GPI-anchored cell surface protein that regulates leukocyte adhesion, migration, and activation, thereby contributing to inflammation and tissue remodeling. However, its role in Alzheimer's disease (AD), particularly in relation to glial dysfunction, remains poorly defined. Here, we investigated the temporal and spatial regulation of uPAR expression across AD mouse models with intact or deficient adaptive immunity. Using immunohistochemistry, we assessed uPAR expression in Rag2/Il2rg[-][/-] (Rag), Rag2/Il2rg[-][/-]-5xFAD (Rag-5xFAD), C57BL/6 (WT), and 5xFAD mice across multiple brain regions. uPAR expression increased with age and was significantly elevated in 5xFAD mice, with robust upregulation evident by 6 months irrespective of immune status. Immunofluorescence revealed that uPAR localized predominantly to Iba1[+] microglia clustered around Aβ plaques, with limited neuronal expression. Bulk RNA sequencing of Rag-5xFAD brain tissue demonstrated enrichment of disease-associated microglia (DAM) and senescence-related transcriptional programs. These findings indicate that uPAR marks a subset of plaque-associated glial cells undergoing functional and transcriptional remodeling in AD, independent of peripheral adaptive immune signaling. Collectively, our results identify uPAR as a marker of dysfunctional, DAM-like microglia and implicate it in senescence-associated neuroinflammatory pathways. This work provides a framework for future studies targeting uPAR-expressing glial populations as a potential therapeutic strategy in AD.

Herbal melanin (HM), previously reported for its antiproliferative and pro-apoptotic properties, has garnered interest as a promising anti-colorectal cancer drug. However, HM's biological effects and underlying molecular mechanisms and the related signaling pathways in colorectal cancer (CRC) cell motility are poorly investigated. To evaluate the impact of various concentrations (50, 100, and 200 μg/mL) of HM on cell migration, invasion, and tumorigenicity on human HT29 and SW620 CRC cell lines, a real-time cell analyzer instrument and colony formation assays were employed, respectively. An angiogenesis-related protein array was also used, and the levels of protein expression contributing to colony formation and extracellular proteolysis-driven cell migration and invasion, such as E-cadherin, N-cadherin and urokinase-type plasminogen activator receptor (uPAR), were monitored using Western blotting and RT-qPCR technologies. HM significantly decreased CRC cell motility, invasiveness, and formation of colonies, associated with E-cadherin upregulation and N-cadherin downregulation. In addition, HM specifically inhibited uPAR expression levels, which were also decreased by the pharmacological mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor UO126 and Jun N-terminal kinase (JNK) inhibitor SP600125, in both CRC cell lines, including metastatic CRC (mCRC) SW620 cell line. Addition of HM to cells pretreated with JNK and MEK inhibitors attenuated the blockade of JNK and ERK phosphorylation and alleviated HM-downregulated uPAR expression and HM-inhibited mCRC cell migration. In conclusion, our in vitro studies demonstrate that HM exhibits an inhibitory effect on CRC migration and invasiveness, associated with uPAR downregulation through JNK and ERK pathways.

The high incidence of thrombosis in lymphoma is largely due to chronic inflammation and endothelial dysfunction. To elucidate the mechanisms underlying thrombus formation and fibrinolysis, we investigated interactions between circulating endothelial cells and peripheral blood mononuclear cells (MNCs), along with inflammatory signaling pathways, in patients with follicular lymphoma (FL), Hodgkin lymphoma (HL), and diffuse large B-cell lymphoma (DLBCL), independent of the presence of thrombosis, compared to healthy controls by flow cytometry, immunoblotting, and fluorometric assays. We observed increased tissue factor (TF) expression on CD31+ endothelial cells in DLBCL and FL. In DLBCL, inducible nitric oxide synthase expression was elevated in MNCs, while reduced nitrite levels correlated with an advanced clinical stage in patients with thrombosis. In lymphoma, nuclear factor kappa B (NFκB) signaling was activated in MNCs, while signal transducer and activator of transcription 3 (STAT3) activation was increased in DLBCL with thrombosis. Trans-endothelial migration of MNC was enhanced in HL, FL and DLBCL with thrombosis and reduced by inflammatory cytokine tumor necrosis factor alpha (TNF-α) that promoted platelet aggregation like interleukin-6 (IL-6) in HL and FL. Fibrinolytic analyses showed reduced tissue type plasminogen activator in lymphoma, whereas increased urokinase-type plasminogen activator (uPA) was linked to poorer total survival in DLBCL with thrombosis, suggesting a compensatory role in early thrombus resolution. These findings indicate that chronic inflammation promotes endothelial activation, dysregulated fibrinolysis, and increased vascular permeability, contributing to heightened thrombotic risk. This study provides mechanistic insight into lymphoma-associated thrombosis and identifies TF, uPA, and the inflammatory signaling pathways as potential biomarkers and therapeutic targets.

Cardiovascular diseases induced by arterial thrombosis, such as myocardial infarction and ischemic stroke, have gradually emerged as critical threats to human life and health. Sequentially targeted delivery systems are highly desired to be developed to improve the delivery of thrombolytics and anti-inflammatory medications to the site of the thrombus, respectively, to pursue a maximized combinational effect. Herein, we developed a probiotic-platelet hybrid vesicle-targeted drug delivery system (Fer-1@PLevs-C&U) to achieve sequential anti-thrombolytic delivery against thrombus and prevent its recurrence. The hybrid vesicles (PLevs) were prepared by mixing platelet membrane with Lactobacillus plantarum-derived bacterial extracellular vesicles (Levs) and further decorated with DSPE-PEG2000-CREKA, achieving "point-to-point" multi-covalent targeting of thrombus components. After targeted localization to the arterial thrombotic site, Fer-1@PLevs-C&U gradually releases the thrombolytic drug urokinase-type plasminogen activator (UPA) and Ferroptosis inhibitor (Fer-1) to facilitate thrombus dissolution and regulate the inflammatory microenvironment. By enhancing the eNOS expression and reducing the secretion of inflammatory factors TNF-α and IL-6, Fer-1@PLevs-C&U significantly reduced the inflammatory microenvironment and inhibited recurrent thrombus. Therefore, Fer-1@PLevs-C&U constitutes a novel biomimetic drug delivery platform with promising therapeutic potential and practical applicability.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive cancer types which 5-year survival is less than 10%. Gemcitabine (GEM) remains the front-line standard-of-care for PDAC; however, pronounced chemoresistance driven by the dense desmoplastic stroma severely constrains its clinical efficacy. The tumor stroma can comprise more than 90% of the total volume, where fibrosis elevates interstitial pressure, compresses blood vessels, impedes penetration, and promotes hypoxia-driven angiogenesis, ultimately forming a vicious cycle. Thus, it is important to attenuate fibrosis and normalize neovasculature for GEM treatment. We therefore designed acid-responsive "rocket-like" Si-G@Ca-H/uPA that exploit Halofuginone (HF), restoring stroma homeostasis, and urokinase plasminogen inhibitor IPR-803 (uPA), loosening the collagen-rich matrix and inhibiting tumor angiogenesis, in the outer shell, followed by GEM-loading mesoporous silica nanoparticles (MSNs) in the core. In this way, the sequential release of HF and uPA remodeled the stroma, enabling deeper penetration of GEM. In PDAC mouse model, Si-G@Ca-H/uPA group showed significantly marked tumor regression without any side effect, presenting great translational potential.

Nicotinic acetylcholine receptor of α7 type (α7-nAChR) is a ligand-gated ion channel composed of five identical α7 subunits. Secreted lymphocyte antigen-6 urokinase-type plasminogen activator receptor (Ly6/uPAR)-related protein-1 (SLURP-1) controls carcinoma progression by negative modulation of oncogenic α7-nAChR. In this study, we observed dramatic decrease of SLURP-1 plasma level in patients with metastatic melanoma. We suggested usage of recombinant analog of human SLURP-1 (rSLURP-1) to compensate this deficiency for metastatic melanoma treatment. rSLURP-1 did not affect viability of different patient-derived metastatic melanoma cells, but reduced migration of some of them. Metastatic melanoma cells of other lines were resistant to rSLURP-1. Antimigratory rSLURP-1 effect was mediated by α7-nAChR, whereas resistance to rSLURP-1 correlated with overexpression of human-specific CHRFAM7A gene, which encodes the α7 subunit with truncated N-terminal region (dupα7) able to form hybrid α7/dupα7-nAChR channels. Electrophysiological study in Xenopus laevis oocytes showed that rSLURP-1 inhibits α7/dupα7-nAChR weaker than α7-nAChR. In contrast, "Oncotag" peptide, which mimics the loop I of SLURP-1, inhibited α7/dupα7- and α7-nAChRs with similar efficiency. Oncotag suppressed metastatic melanoma cell migration independently on dupα7 expression. Computer modeling provided rationale for altered activities of rSLURP-1 and Oncotag on α7/dupα7-nAChR. The Cancer Genome Atlas Program (TCGA) database analysis revealed correlation between CHRNΑ7 and CHRFAM7A gene expression and worse survival prognosis for patients with metastatic melanoma. Thus, 1) low plasma SLURP-1 level may be a specific marker of metastatic melanoma development, 2) metastatic melanoma progression can be controlled by α7-nAChR inhibition, and 3) dupα7 overexpression is a new molecular mechanism of melanoma resistance to internal cholinergic control and new target for melanoma treatment.NEW & NOTEWORTHY Metastatic melanoma is aggressive skin tumor often resistant to standard therapies. High α7-nAChR expression negatively correlates with survival of patients with metastatic melanoma, who are characterized by SLURP-1 drop in the plasma. Targeting α7-nAChR with recombinant SLURP-1 could significantly suppress metastatic melanoma cell migration; however, overexpression of human-specific dupα7 subunit forming hybrid α7/dupα7-nAChRs causes melanoma resistance to SLURP-1. This resistance can be overcome by the SLURP-1 mimicking peptide Oncotag, which exhibits activity against hybrid α7/dupα7-nAChRs.