Search Results (283)

Glioblastoma multiforme (GBM) remains one of the most aggressive and treatment-resistant brain tumors, with poor prognosis and limited therapeutic options. Background/Objectives: Integrin α_vβ₃, a cell surface receptor overexpressed in GBM, specifically binds to cyclic arginine-glycine-aspartate-D-phenylalanine-lysine (c(RGDfK)) motif, making it a valuable target for tumor-specific delivery and PET imaging. This study explores a novel radiotheranostic agent, [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK), which combines the imaging and therapeutic capabilities of copper-64 (⁶⁴Cu) and the cytotoxic activity of a terpyridine-platinum (TP) complex, conjugated to c(RGDfK). Methods: A robust protocol was developed for the small-scale preparation of NOTA-TP-c(RGDfK). Comparative cellular studies were conducted using U87 MG glioblastoma (GBM) cells and SVG p12 human astrocytes to evaluate the performance of [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) relative to [⁶⁴Cu]Cu-NOTA-c(RGDfK), [⁶⁴Cu]Cu-NOTA-TP, ^natCu-NOTA-TP-c(RGDfK), cisplatin, and temozolomide. Results: ⁶⁴Cu-radiolabeling of NOTA-TP-c(RGDfK) was achieved with >99% radiochemical purity, and competition assays confirmed high binding affinity to integrin α_vβ₃ (IC₅₀ = 16 ± 8 nM). Cellular uptake, internalization, and retention studies demonstrated significantly higher accumulation of [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) in U87 MG cells compared to control compounds, with 38.8 ± 1.8% uptake and 28.0 ± 1.0% internalization at 24 h. Nuclear localization (6.0 ± 0.5%) and stable intracellular retention further support its therapeutic potential for inducing localized DNA damage. Importantly, [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) exhibited the highest cytotoxicity in U87 MG cells (IC₅₀ = 10 ± 2 nM at 48 h), while maintaining minimal toxicity in normal SVG p12 astrocytes. Conclusions: These results highlight [⁶⁴Cu]Cu-NOTA-TP-c(RGDfK) as a promising targeted radiotheranostic agent for GBM, warranting further preclinical development Full article

Background and aim: ANGPTL3 is a hepatokine acting as a negative regulator of lipoprotein lipase (LPL) through its N-terminal domain. Besides this activity, the C-terminal domain of ANGPTL3 interacts with integrin αVβ3. Since integrins are involved in inflammation and in the initiation of atherosclerotic plaque, the aim of our study was to evaluate the potential direct pro-inflammatory action of ANGPTL3 through the interaction of the fibrinogen-like domain and integrin αVβ3. Methods: We utilized cultured THP-1 human-derived macrophages and evaluated their pro-inflammatory phenotype in response to treatment with human recombinant ANGPTL3 (hANGPTL3). By Western blot, RT-qPCR, biochemical analysis, and ELISA assays, we determined the expression of genes and proteins involved in lipid metabolism and inflammatory response as well as intracellular cholesterol and triglyceride levels. In addition, we evaluated the effect of hANGPTL3 on the cellular cholesterol efflux process. Results: Incubation of THP-1-derived macrophages with 100 ng/mL of hANGPTL3 increased the mRNA expression of the pro-inflammatory cytokines IL-1β, IL-6, and TNFα (respectively, 1.87 ± 0.08-fold, 1.35 ± 0.11-fold, and 2.49 ± 0.43-fold vs. control). The secretion of TNFα, determined by an ELISA assay, was also induced by hANGPTL3 (1.98 ± 0.4-fold vs. control). The pro-inflammatory effect of hANGPTL3 was partially counteracted by co-treatment with the integrin αVβ3 inhibitor RGD peptide, reducing the mRNA levels of IL-1β (3.35 ± 0.35-fold vs. 2.54 ± 0.25-fold for hANGPTL3 vs. hANGPTL3 + RGD, respectively). Moreover, hANGPTL3 reduced cholesterol efflux to apoA-I, with a parallel increase in the intracellular triglyceride and cholesterol contents by 31.2 ± 2.8% and 20.0 ± 4.1%, respectively, compared to the control. Conclusions: ANGPTL3 is an important liver-derived regulator of plasma lipoprotein metabolism, and overall, our results add a new important pro-inflammatory activity of this circulating protein. This new function of ANGPTL3 could also be related to triglyceride and cholesterol accumulation into macrophages. Full article

Several of the integrin family of cell adhesion receptors have been popular targets for the development of anticancer agents, but with little clinical success to date. Cancer cells usually express multiple redundant integrins; one hypothesis for the lack of efficacy of current antagonists is their high selectivity for a single integrin. To address this, we developed a functional dual-β3-expressing cell model to investigate the effects of combined αIIbβ3/αvβ3 antagonism. We established that treating K562 chronic myeloid leukemia cells with 0.04 μM phorbol 12-myristate 13-acetate (PMA) for 40 h significantly upregulates functional αIIbβ3 and αvβ3 integrins. This optimized method provides a reliable platform for adhesion and detachment assays, enabling the characterization of dual integrin targeting strategies. Using this model, we demonstrate that combining αIIbβ3 and αvβ3 antagonists (GR144053 and cRGDfV) synergistically enhances inhibition of cell adhesion and promotes cell detachment compared to single-agent treatments. Our findings establish a reproducible approach for studying dual β3 integrin targeting, which can be used to investigate potential strategies for overcoming integrin redundancy in cancer therapeutics. Full article

Background/Objectives: Tetrastatin, the globular non collagenous (NC1) domain of the α4 chain of collagen IV, was previously demonstrated to inhibit melanoma progression. We identified the minimal active sequence (QKISRCQVCVKYS: QS-13) that reproduced the anti-tumor effects of whole Tetrastatin and demonstrated its anti-angiogenic activity mediated through αvβ3 and α5β1 binding. As QS-13 peptide was not fully soluble in aqueous solution, we designed new peptides with better water solubility. The present work aimed to investigate the interactions of ten QS-13-derived peptides, exhibiting improved hydro-solubility, with αvβ3 and α5β1 integrins. Methods: Using bioinformatics tools such as GROMACS, VMD, and the Autodock4 suite, we investigated the ability of the substituted peptides to bind αvβ3 and α5β1 integrins in silico. Results: We demonstrated in silico that all substituted peptides were able to bind both integrins at the RGD-binding site and determined their theoretical binding energy. Conclusions: The new soluble peptides should be able to compete with natural integrin ligands such as fibronectin, but also FGF1, FGF2, IGF1, and IGF2. Taken together, these findings suggest that the QS-13-derived peptides are reliable anti-angiogenic and anti-tumor agents. Full article

This review looks at the causes of the association between thyroid dysfunction (hyperthyroidism and hypothyroidism) and ovarian cancer (OC) risk. Epidemiological data have revealed that thyroid dysfunction, particularly hyperthyroidism, is associated with increased risk, progression, and mortality in patients with OC. In addition, research studies and databases have demonstrated that both the expression and localization of thyroid hormone receptors alpha (TRα) and beta (TRβ) and membrane thyroid hormone receptor integrin alpha V beta 3 (αvβ3) affect OC progression and survival in OC patients. Furthermore, this review described the levels of the thyroid hormones (THs) thyroxine (T₄) and 3,5,3′-triiodo-L-thyronine (T₃) in the blood of OC patients and their role in OC progression. Moreover, we present studies that reported the relationship between hyperthyroidism and hypothyroidism and the levels of metabolic hormones in the blood and the possible effects on metabolic reprogramming in OC cells. We also report data indicating the relationship between the treatment of thyroid dysfunction and OC progression. Finally, the cited case studies described the essential case of struma ovarii, which is OC, including thyroid tissue. This review describes the link between thyroid dysfunction and OC risk and progression, which may be important in treating OC patients with thyroid dysfunction. Full article

Polyunsaturated fatty acids (PUFAs) play roles in several physiological and pathophysiological processes, but their effects on reproductive function are controversial. The aim of the study was to investigate the effect of n-3 PUFA-rich fish oil and n-6-rich sunflower oil on sex hormone status, in vivo and in vitro uterine contractility, and endometrial remodeling. Female Sprague Dawley, Lister hooded, and Wistar rats were treated orally for 20 days with 1 mL of tap water, sunflower oil, or fish oil. Blood samples were taken for gonadotropic and sex hormone analysis. In vivo smooth muscle contractions were measured weekly by electromyography. Isolated uterine and cecal contractions were measured after sacrificing the animals. Endometrial remodeling was detected based on the presence of αvβ3 integrin by optical imaging. In Sprague Dawley rats, fish oil increased the LH level and progesterone/estradiol (P4/E2) ratio compared to the sunflower oil-treated group. Uterine contractions were reduced both in vitro and in vivo. Endometrial αvβ3 integrin activity was increased in the fish oil group. In Lister hooded rats, neither sunflower nor fish oil treatments modified the investigated parameters. However, in Wistar rats, both oils increased only the in vivo contractions and reduced the P4/E2 ratio, along with αvβ3 integrin fluorescence. n-3 PUFA-rich fish oil induces a breed-dependent effect on sex hormone status and uterine contractions in rats. The response to PUFA intake may vary significantly within a given species, which may have importance both in animal feeding and human nutrition. Full article

Cysteine-rich protein 61 (CYR61) is a matricellular protein in the CCN family that is involved in cellular adhesion, migration, proliferation, and angiogenesis. CYR61 interacts with integrins α6β1, αvβ3, αvβ5, and αIIbβ3 to modulate tumor progression and metastasis while modifying the tumor microenvironment. CYR61 exhibits context-dependent roles in cancer, acting as both a tumor promoter and suppressor. Increased CYR61 expression is linked to extracellular matrix remodeling, immune modulation, and integrin-mediated signaling, making it a potential prognostic biomarker and therapeutic target. Emerging research highlights the utility of CYR61 in liquid biopsies for cancer detection and monitoring. Integrin-targeted therapies, including CYR61-blocking antibodies and CAR-T approaches, offer novel treatment strategies. However, therapy-induced toxicity and resistance remain challenges with these strategies. The further elucidation of the molecular mechanisms of CYR61 may enhance targeted therapeutic interventions and improve patient outcomes. Full article

Background/Objectives: CAR T cell therapy, as a rapidly advancing immuno-oncology modality, has achieved significant success in the treatment of leukaemia and lymphoma. However, its application in solid tumours remains limited. The challenges include the heterogeneity of tumours, local immunosuppression, poor trafficking and infiltration, life-threatening toxicity and the lack of precise representative immunocompetent research models. Considering its typically dense and immunosuppressive tumour microenvironment (TME) and early metastasis, pancreatic ductal adenocarcinoma (PDAC) was employed as a model to address the challenges that hinder CAR T cell therapies against solid tumours and to expand immunotherapeutic options for advanced disease. Methods: A novel murine A20FMDV2 (A20) CAR T cell targeting integrin αvβ6 (mA20CART) was developed, demonstrating efficient and specific on-target cytotoxicity. The mA20CART cell as a monotherapy for orthotopic pancreatic cancer in an immunocompetent model demonstrated modest efficacy. Therefore, a novel triple therapy regimen, combining mA20CART cells with oncolytic vaccinia virus encoding IL-21 and a TGF-β-blocking antibody was evaluated in vivo. Results: The triple therapy improved overall survival, improved the safety profile of the CAR T cell therapy, attenuated metastasis and enhanced T cell infiltration. Notably, the potency of mA20CART was dependent on IL-2 supplementation. Conclusions: This study presents an αvβ6-targeting murine CAR T cell, offering a novel approach to developing CAR T cell technologies for solid tumours and a potential adjuvant therapy for pancreatic cancer. Full article

Background/Objectives: Molecular imaging, especially PET, has advanced significantly, shifting from metabolic radiotracers like 2-deoxy-2-[¹⁸F]fluoro-D-glucose [¹⁸F]FDG to target-specific probes. Among these, αvβ6-integrin has emerged as a promising target in cancer and non-cancer diseases. This review focuses on the radiochemical properties and initial clinical applications of the [⁶⁸Ga]Ga-Trivehexin PET probe. Methods: The literature review on [⁶⁸Ga]Ga-Trivehexin systematically evaluated both preclinical and clinical studies, with particular emphasis on its radiochemical characteristics and preliminary clinical applications, while highlighting advancements, associated challenges, and the potential for future developments in the field. Results: This study highlights the significant advancements achieved with [⁶⁸Ga]Ga-Trivehexin in the field of molecular imaging. The optimized multimeric system has substantially enhanced the radiotracer’s pharmacokinetic properties, binding affinity, and selectivity for αvβ6 integrin, demonstrating up to an 18-fold improvement compared to previous monomeric tracers. The synthesis protocol has been refined to achieve high radiochemical purity (>95%), essential for safe clinical use. Preliminary clinical applications, particularly in head and neck cancer (HNC) and pancreatic ductal adenocarcinoma (PDAC), have shown promising results, with high detection rates and improved differential diagnosis compared to [¹⁸F]FDG. Furthermore, [⁶⁸Ga]Ga-Trivehexin PET/CT has shown potential in non-oncological conditions, such as idiopathic pulmonary fibrosis (IPF) and primary hyperthyroidism, suggesting broader clinical applicability. Conclusions: [⁶⁸Ga]Ga-Trivehexin is a promising PET probe for imaging αvβ6-integrin in cancers and non-oncological diseases like idiopathic pulmonary fibrosis (IPF) and primary hyperparathyroidism (PHP). Full article

We showed that multiple inflammatory cytokines (e.g., CCL5, CXCL12, CX3CL1, CD40L, and FGF2) bind to the allosteric site (site 2) of integrins, distinct from the classical RGD-binding site (site 1), and allosterically activate integrins. A major inflammatory lipid mediator 25-hydroxycholesterol is known to bind to site 2 and allosterically activates integrins and induces inflammatory signals (e.g., IL-6 and TNF secretion). Thus, site 2 is involved in inflammatory signaling. Neuregulin-1 (NRG1) is known to suppresses the progression of inflammatory diseases, fibrosis, and insulin resistance. But, the mechanism of anti-inflammatory action of NRG1 is unclear. We previously showed that NRG1 binds to the classical RGD-binding site (site 1). Mutating the 3 Lys residues that are involved in site 1 binding (NRG1 3KE mutant) is defective in binding to site 1 and in ErbB3-mediated mitogenic signals. Docking simulation predicted that NRG1 binds to site 2. We hypothesized that NRG1 acts as an antagonist of site 2 and blocks allosteric activation by multiple cytokines. Here, we describe that NRG1 binds to site 2 but does not activate soluble αvβ3 or αIIbβ3 in 1 mM Ca²⁺, unlike inflammatory cytokines. Instead, NRG1 suppressed integrin activation by several inflammatory cytokines, suggesting that NRG1 acts as a competitive inhibitor of site 2. Wild-type NRG1 is not suitable for long-term treatment due to its mitogenicity. We showed that the non-mitogenic NRG1 3KE mutant still bound to site 2 and inhibited allosteric activation of soluble and cell-surface integrins, suggesting that NRG1 3KE may have potential as a therapeutic. Full article

Background/Objectives: Integrin α_Vβ₃ plays a crucial role in tumor angiogenesis and cancer progression, making it a key target for radiolabeled probes used in imaging and therapy. A previously developed probe, [¹²⁵I]bcRGD, exhibited high selectivity for α_Vβ₃ but limited tumor accumulation due to rapid blood clearance. This study aimed to address this issue through two strategies: (1) conjugating albumin-binding molecules to enhance systemic circulation and (2) dimerizing RGD peptides to improve binding affinity via multivalency effects. Methods: Three [¹²⁵I]bcRGD derivatives were synthesized: [¹²⁵I]bcRGD_pal (with palmitic acid), [¹²⁵I]bcRGD_iba (with 4-(p-iodophenyl)butyric acid), and [¹²⁵I]bcRGD_dimer (a dimeric bicyclic RGD peptide). Their physicochemical properties, α_Vβ₃-selectivity, albumin-binding capacity, and biodistribution were assessed in vitro and in vivo using tumor-bearing mice. Tumor models included α_Vβ₃-high U-87 MG and α_Vβ₃-low A549 xenografts. Results: [¹²⁵I]bcRGD_pal and [¹²⁵I]bcRGD_iba exhibited prolonged blood retention (30-fold and 55-fold vs. [¹²⁵I]bcRGD, respectively) and increased tumor accumulation (3.9% ID/g and 3.6% ID/g at 2 h, respectively). Despite improved systemic circulation, tumor-to-blood ratios remained low (<1), indicating limited tumor retention. [¹²⁵I]bcRGD_dimer achieved significantly greater tumor accumulation (4.2% ID/g at 2 h) and favorable tumor-to-blood (22) and tumor-to-muscle (14) ratios, with a 5.4-fold higher uptake in U-87 MG tumors compared to A549 tumors. Conclusions: Dimerization was more effective than albumin binding in enhancing bcRGD’s tumor-targeting potential. The dimeric probe demonstrated improved tumor accumulation, favorable pharmacokinetics, and preserved integrin selectivity. These findings provide a foundation for further structural optimization of bicyclic RGD peptides for integrin α_Vβ₃-targeted imaging and therapy applications. Full article

Exosomes can transport regulatory biomolecules and are mediators of cellular signaling among metabolic tissues through endocrine mechanisms. Understanding the pathways and processes underlying exosome-mediated inter-tissue communication is critical for elucidating the molecular pathophysiology of metabolic diseases such as obesity, type 2 diabetes mellitus (T2DM), and cardiovascular disorders. Consequently, these mechanisms represent novel and promising targets for pharmacological regulation. We examined the current knowledge regarding exosome physiology, the mechanisms of interaction with target tissues, and its role in metabolic tissue communication. We also analyzed the secretory profiles of exosomes in metabolic tissues, emphasizing their regulatory roles in adipose tissue, liver, pancreas, skeletal muscle, and the small intestine, while discussing their association with metabolic diseases. In this sense, we propose the exosomal pentad as a novel framework highlighting exosome-mediated inter-organ communication, where exosomes may regulate a metabolic axis involving these tissues. This model aligns with the ominous octet in type 2 diabetes but emphasizes exosomes as key regulators of metabolic homeostasis and potential therapeutic targets. The role of exosomes for the treatment of metabolic diseases emerges as a critical area of pharmacologic exploration. For instance, therapeutic strategies that prevent target tissue binding or expression of cargo molecules such as miRNAs could be designed, using antagomiRs or nanoparticles. Additionally, integrins like αvβ5 on the exosomal membrane can be blocked with monoclonal antibodies or engineered for targeted delivery of therapeutic molecules. Exosomes, critical mediators of inter-organ communication and metabolic regulation, hold potential to design precise molecular-level therapies while minimizing systemic side effects. Full article

The clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system is a promising biotechnology tool for genome editing. However, in living organisms, several pharmacokinetic challenges arise, including off-target side effects due to incorrect distribution, low bioavailability caused by membrane impermeability, and instability resulting from enzymatic degradation. Therefore, innovative delivery strategies must be developed to address these issues. Modified nanoparticles offer a potential solution for the non-invasive delivery of CRISPR/Cas9 ribonucleoproteins (Cas9 RNPs). Cas9 RNPs encapsulated in nanoparticles are protected from enzymatic degradation, similar to how microRNAs are shielded within exosomes. It is well-established that certain materials, including proteins, are expressed selectively in specific cell types. For example, the α-7 nicotinic receptor is expressed in endothelial and neuronal cells, while the αvβ3 integrin is expressed in cancer cells. These endogenous materials can facilitate receptor-mediated endocytosis or transcytosis. Nanoparticles encapsulating Cas9 RNPs and coated with ligands targeting such receptors may be internalized through receptor-mediated mechanisms. Once internalized, Cas9 RNPs could perform the desired gene editing in the nucleus after escaping the endosome through mechanisms such as the proton sponge effect or membrane fusion. In this review, I discuss the potential and advantages of delivering Cas9 RNP-encapsulated nanoparticles coated with ligands through receptor-mediated endocytosis or transcytosis. Full article

Background: Alpha radionuclide therapy has emerged as a promising novel strategy for cancer treatment; however, the therapeutic potential of ²²⁵Ac-labeled peptides in pancreatic cancer remains uninvestigated. Methods: In the cytotoxicity study, tumor cells were incubated with ²²⁵Ac-DOTA-RGD₂. DNA damage responses (γH2AX and 53BP1) were detected using flowcytometry or immunohistochemistry analysis. Biodistribution and therapeutic studies were carried out in BxPC-3-bearing mice. Results: ²²⁵Ac-DOTA-RGD₂ demonstrated potent cytotoxicity against cells expressing α_vβ₃ or α_vβ₆ integrins and induced G2/M arrest and γH2AX expression as a marker of double-stranded DNA breaks. ²²⁵Ac-DOTA-RGD₂ (20, 40, 65, or 90 kBq) showed favorable pharmacokinetics and remarkable tumor growth inhibition without severe side effects in the BxPC-3 mouse model. In vitro studies revealed that 5 and 10 kBq/mL of ²²⁵Ac-DOTA-RGD₂ swiftly induced G2/M arrest and elevated γH2AX expression. Furthermore, to clarify the mechanism of successful tumor growth inhibition for a long duration in vivo, we investigated whether short-term high radiation exposure enhances radiation sensitivity. Initially, a 4 h induction treatment with 5 and 10 kBq/mL of ²²⁵Ac-DOTA-RGD₂ enhanced both cytotoxicity and γH2AX expression with 0.5 kBq/mL of ²²⁵Ac-DOTA-RGD₂ compared to a treatment with only 0.5 kBq/mL of ²²⁵Ac-DOTA-RGD₂. Meanwhile, the γH2AX expression induced by 5 or 10 kBq/mL of ²²⁵Ac-DOTA-RGD₂ alone decreased over time. Conclusions: These findings highlight the potential of using ²²⁵Ac-DOTA-RGD₂ in the treatment of intractable pancreatic cancers, as its ability to induce G2/M cell cycle arrest enhances radiosensitization, resulting in notable growth inhibition. Full article

Liver metastases frequently occur in pancreatic and colorectal cancer. Their development is promoted by tumor-derived exosomes with the integrin α_Vβ₅ on their membrane. This integrin directs exosomes to the liver, where they promote a TGF-β-dependent pre-metastatic niche. We proposed the development of α_Vβ₅⁺ exosomes to deliver anti-TGF-β therapy to the liver. This study demonstrates that the overexpression of α_Vβ₅ in 293T cells allows its transfer to the secreted exosomes. α_Vβ₅ overexpression increases exosome delivery to the liver, and α_Vβ₅⁺ exosomes accumulate more in the liver compared to the lungs, kidneys, and brain in mice. We then sought 293T cells to directly produce and load an anti-TGF-β agent in their exosomes. First, we transduced 293T cells to express shRNAs against Tgfb1; however, the exosomes isolated from these cells did not knock down Tgfb1 in treated macrophages in vitro. However, when 293T expressed an mRNA coding a soluble form of betaglycan (sBG), a TGF-β inhibitor, this mRNA was detected in the isolated exosomes and the protein in the conditioned media of macrophages treated in vitro. In turn, this conditioned media decreased the TGF-β-induced phosphorylation of SMAD2/3 in hepatic cells in vitro. Our findings suggest that α_Vβ₅⁺ exosomes could serve as nanocarriers for liver-targeted anti-TGF-β therapies. Full article