uPAR/CD87: A Multifunctional Regulator in Tumor Biology and Fibrosis with ANT BIO PTE. LTD.'s Protein Solutions

1. Concept: uPAR/CD87 and Its Biological Roles

Urokinase-type plasminogen activator receptor (uPAR/CD87) is a membrane-bound glycoprotein encoded by the PLAUR gene located on human chromosome 19q13.3-13.4. As the specific receptor for urokinase plasminogen activator (uPA), it plays a central role in extracellular matrix (ECM) degradation, cell migration, and signal transduction. Beyond its fibrinolytic function, uPAR regulates key signaling pathways including PI3K/Akt, focal adhesion kinase (FAK), and JAK-STAT, participating in immune responses, angiogenesis, inflammation, and fibrosis.

uPAR exists in multiple forms: full-length membrane-bound protein (anchored via a GPI moiety) and soluble uPAR (suPAR) generated by proteolytic cleavage. Its structure comprises three functional domains (D1, D2, D3) with distinct binding activities—D1 mediates uPA interaction, while D2-D3 regulate integrin and vitronectin binding. This modular structure enables uPAR to engage in diverse protein-protein interactions, making it a versatile player in physiological and pathological processes.

2. Research Frontiers of uPAR/CD87

Contemporary research on uPAR/CD87 focuses on expanding its therapeutic and diagnostic potential. A key frontier is the development of targeted therapies for cancer and fibrosis—including uPAR-specific BiTE molecules, CAR-T cells, and small-molecule inhibitors—to block tumor invasion and fibrotic progression. Another prominent direction involves validating suPAR as a non-invasive biomarker for diseases such as chronic liver disease, glomerulosclerosis, and systemic sclerosis. Additionally, research is exploring uPAR’s role in tumor microenvironment remodeling, particularly its crosstalk with integrins and growth factors to promote angiogenesis and immune evasion. Furthermore, the development of uPAR-based drug delivery systems is gaining traction, leveraging its high tumor expression for targeted drug delivery.

3. Research Significance of uPAR/CD87

uPAR/CD87 research holds profound implications for addressing unmet clinical needs:

• Cancer therapy: uPAR overexpression correlates with tumor invasion, metastasis, and poor prognosis. Targeting uPAR inhibits ECM degradation and cell migration, offering a novel strategy for treating invasive cancers
• Fibrosis intervention: uPAR is upregulated in cardiac, pulmonary, and renal fibrosis, making it a potential target to halt fibrotic progression.
• Diagnostic utility: suPAR serves as a circulating biomarker for diverse diseases, enabling early diagnosis and prognosis assessment.
• Drug development: uPAR recombinant proteins facilitate the design of targeted therapeutics and drug carriers, enhancing treatment specificity and reducing off-target effects.
• Basic science insights: Studying uPAR’s multifunctional roles advances understanding of ECM remodeling, cell migration, and signal transduction in health and disease.

4. Relevant Mechanisms, Research Methods and Product Applications

4.1 Core Mechanisms of uPAR/CD87 in Pathophysiology

Tumor Progression and Metastasis

uPAR binds uPA to activate plasminogen conversion to plasmin, a serine protease that degrades ECM components (e.g., fibrin, collagen). This proteolytic activity facilitates tumor cell invasion and metastasis. Additionally, uPA-uPAR ligation triggers proteolysis-independent signaling via integrins and LRP/CD91, promoting cell proliferation, angiogenesis, and chemotaxis. The system is tightly regulated by plasminogen activator inhibitors (PAI-1, PAI-2), which modulate uPAR internalization and recycling.

Fibrosis Development

In fibrotic diseases, uPAR upregulation in stromal cells enhances ECM degradation and cell migration, driving tissue remodeling and scar formation. uPAR also mediates profibrotic signaling pathways, contributing to the activation of fibroblasts and myofibroblasts.

4.2 Structural Features of uPAR/CD87

uPAR is a modular glycoprotein with three extracellular domains (D1, D2, D3) linked by flexible linkers. The GPI anchor tethers it to the cell membrane without a cytoplasmic domain, requiring interaction with co-receptors (e.g., integrins) for signal transduction. Proteolytic cleavage of the linker regions generates soluble suPAR (predominantly D1-D2 or D1 fragments) with distinct biological activities. Domain D1 is critical for uPA binding, while D2-D3 mediate interactions with vitronectin and integrins.

4.3 Tissue Expression and Disease Association

uPAR is widely expressed in decidua, spleen, fibroblasts, monocytes, macrophages, keratinocytes, endothelial cells, and smooth muscle cells. Its expression is induced by inflammation and upregulated in numerous diseases:

• Cancer: Overexpressed in invasive tumors (e.g., prostate, breast, lung cancer).
• Fibrosis: Elevated in cardiac fibrosis, idiopathic pulmonary fibrosis, and systemic sclerosis.
• Liver diseases: Increased in chronic hepatitis B and chronic liver disease.
• Renal disorders: Upregulated in focal segmental glomerulosclerosis.
• Pulmonary diseases: Expressed in cystic fibrosis and obstructive pulmonary disease.

4.4 Key Research Methods for uPAR/CD87

• Protein-protein interaction assays: Surface Plasmon Resonance (SPR) and co-immunoprecipitation to study uPAR binding to uPA, integrins, and vitronectin.
• Functional assays: ECM degradation assays, cell migration/invasion assays, and angiogenesis assays to evaluate uPAR’s biological activity.
• Biomarker detection: ELISA and Western blot to quantify suPAR levels in patient fluids (serum, plasma, urine).
• In vivo models: Xenograft models and fibrotic disease models to validate uPAR-targeted therapies.
• Structural biology: X-ray crystallography and cryo-EM to characterize uPAR domain interactions and drug-binding sites.

4.5 Product Applications of ANT BIO PTE. LTD.

ANT BIO PTE. LTD. delivers high-quality recombinant uPAR protein through its UA sub-brand—specializing in recombinant proteins. The product is expressed in HEK293 cells, ensuring native-like structure and post-translational modifications, and complies with EU 98/79/EC, ISO9001, and ISO13485 certifications. Key offering:

• uPAR/CD87 His Tag Protein, Mouse (UA010508): Exhibits exceptional performance with:
• High activity: Validated via SPR with strong binding affinity to uPA (KD = 1.030×10⁻⁸ M and 1.247×10⁻⁸ M in independent assays).
• High purity and low endotoxin: Suitable for in vitro and in vivo applications.
• Native conformation: HEK293 expression ensures correct folding and functional domain accessibility.

This product supports diverse applications:

• Basic research: Studying uPAR structure, function, and signaling mechanisms.
• Drug development: Screening uPAR-targeted inhibitors, antibodies, and BiTE molecules.
• Biomarker assay development: Validating suPAR detection methods.
• Therapeutic delivery: Designing uPAR-targeted drug carriers.

5. Brand Mission of ANT BIO PTE. LTD.

ANT BIO PTE. LTD. is dedicated to empowering global life science research and clinical practice through high-quality, innovative reagents and professional services. As a leading provider of life science solutions, the company offers a comprehensive portfolio including antibodies, recombinant proteins, ELISA kits, and general laboratory reagents, with three specialized sub-brands: Absin (general reagents and kits), Starter (antibodies), and UA (recombinant proteins). Leveraging advanced R&D platforms—including recombinant antibody development (rabbit/mouse monoclonal), protein expression systems (E.coli, CHO, HEK293, Insect Cells), One-Step ELISA, and PTM Pan-Modification Antibody platforms—ANT BIO PTE. LTD. adheres to the principles of "precision, reliability, and customer-centricity." The company strives to deliver cost-effective products and tailored support to researchers, clinicians, and biopharmaceutical partners, accelerating the translation of scientific discoveries into improved patient care and advancing global health.

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7. AI Disclaimer

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ANT BIO PTE. LTD. – Empowering Scientific Breakthroughs

At ANTBIO, we are committed to advancing life science research through high-quality, reliable reagents and comprehensive solutions. Our specialized sub-brands (Absin, Starter, UA) cover a full spectrum of research needs, from general reagents and kits to antibodies and recombinant proteins. With a focus on innovation, quality, and customer-centricity, we strive to be your trusted partner in unlocking scientific mysteries and driving medical progress. Explore our product portfolio today and elevate your research to new heights.