-
Neoplasia (New York, N.Y.) 2001Coagulopathy and angiogenesis are among the most consistent host responses associated with cancer. These two respective processes, hitherto viewed as distinct, may in... (Review)
Review
Coagulopathy and angiogenesis are among the most consistent host responses associated with cancer. These two respective processes, hitherto viewed as distinct, may in fact be functionally inseparable as blood coagulation and fibrinolysis, in their own right, influence tumor angiogenesis and thereby contribute to malignant growth. In addition, tumor angiogenesis appears to be controlled through both standard and non-standard functions of such elements of the hemostatic system as tissue factor, thrombin, fibrin, plasminogen activators, plasminogen, and platelets. "Cryptic" domains can be released from hemostatic proteins through proteolytic cleavage, and act systemically as angiogenesis inhibitors (e.g., angiostatin, antiangiogenic antithrombin III aaATIII). Various components of the hemostatic system either promote or inhibit angiogenesis and likely act by changing the net angiogenic balance. However, their complex influences are far from being fully understood. Targeted pharmacological and/or genetic inhibition of pro-angiogenic activities of the hemostatic system and exploitation of endogenous angiogenesis inhibitors of the angiostatin and aaATIII variety are under study as prospective anti-cancer treatments.
Topics: Animals; Hemostasis; Humans; Neoplasms; Neovascularization, Pathologic
PubMed: 11687948
DOI: 10.1038/sj.neo.7900184 -
Arthritis Research 2002The expansion of the synovial lining of joints in rheumatoid arthritis (RA) and the subsequent invasion by the pannus of underlying cartilage and bone necessitate an... (Review)
Review
The expansion of the synovial lining of joints in rheumatoid arthritis (RA) and the subsequent invasion by the pannus of underlying cartilage and bone necessitate an increase in the vascular supply to the synovium, to cope with the increased requirement for oxygen and nutrients. The formation of new blood vessels - termed 'angiogenesis' - is now recognised as a key event in the formation and maintenance of the pannus in RA. This pannus is highly vascularised, suggesting that targeting blood vessels in RA may be an effective future therapeutic strategy. Disruption of the formation of new blood vessels would not only prevent delivery of nutrients to the inflammatory site, but could also lead to vessel regression and possibly reversal of disease. Although many proangiogenic factors are expressed in the synovium in RA, the potent proangiogenic cytokine vascular endothelial growth factor (VEGF) has been shown to a have a central involvement in the angiogenic process in RA. The additional activity of VEGF as a vascular permeability factor may also increase oedema and hence joint swelling in RA. Several studies have shown that targeting angiogenesis in animal models of arthritis ameliorates disease. Our own study showed that inhibition of VEGF activity in murine collagen-induced arthritis, using a soluble VEGF receptor, reduced disease severity, paw swelling, and joint destruction. Although no clinical trials of anti-angiogenic therapy in RA have been reported to date, the blockade of angiogenesis - and especially of VEGF - appears to be a promising avenue for the future treatment of RA.
Topics: Animals; Arthritis, Rheumatoid; Humans; Neovascularization, Pathologic
PubMed: 12110126
DOI: 10.1186/ar575 -
The Oncologist Jun 2015Angiogenesis, or the formation of new capillary blood vessels, occurs primarily during human development and reproduction; however, aberrant regulation of angiogenesis... (Review)
Review
UNLABELLED
Angiogenesis, or the formation of new capillary blood vessels, occurs primarily during human development and reproduction; however, aberrant regulation of angiogenesis is also a fundamental process found in several pathologic conditions, including cancer. As a process required for invasion and metastasis, tumor angiogenesis constitutes an important point of control of cancer progression. Although not yet completely understood, the complex process of tumor angiogenesis involves highly regulated orchestration of multiple signaling pathways. The proangiogenic signaling molecule vascular endothelial growth factor (VEGF) and its cognate receptor (VEGF receptor 2 [VEGFR-2]) play a central role in angiogenesis and often are highly expressed in human cancers, and initial clinical efforts to develop antiangiogenic treatments focused largely on inhibiting VEGF/VEGFR signaling. Such approaches, however, often lead to transient responses and further disease progression because angiogenesis is regulated by multiple pathways that are able to compensate for each other when single pathways are inhibited. The platelet-derived growth factor (PDGF) and PDGF receptor (PDGFR) and fibroblast growth factor (FGF) and FGF receptor (FGFR) pathways, for example, provide potential escape mechanisms from anti-VEGF/VEGFR therapy that could facilitate resumption of tumor growth. Accordingly, more recent treatments have focused on inhibiting multiple signaling pathways simultaneously. This comprehensive review discusses the limitations of inhibiting VEGF signaling alone as an antiangiogenic strategy, the importance of other angiogenic pathways including PDGF/PDGFR and FGF/FGFR, and the novel current and emerging agents that target multiple angiogenic pathways for the treatment of advanced solid tumors.
IMPLICATIONS FOR PRACTICE
Significant advances in cancer treatment have been achieved with the development of antiangiogenic agents, the majority of which have focused on inhibition of the vascular endothelial growth factor (VEGF) pathway. VEGF targeting alone, however, has not proven to be as efficacious as originally hoped, and it is increasingly clear that there are many interconnected and compensatory pathways that can overcome VEGF-targeted inhibition of angiogenesis. Maximizing the potential of antiangiogenic therapy is likely to require a broader therapeutic approach using a new generation of multitargeted antiangiogenic agents.
Topics: Angiogenesis Inhibitors; Fibroblast Growth Factors; Humans; Molecular Targeted Therapy; Neoplasms; Neovascularization, Pathologic; Platelet-Derived Growth Factor; Signal Transduction; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-1
PubMed: 26001391
DOI: 10.1634/theoncologist.2014-0465 -
Asian Pacific Journal of Cancer... Jun 2022Angiogenesis plays a key role in tumor growth, invasion, and metastasis of cancer diseases, and therefore, the inhibition of angiogenesis can provide an important...
OBJECTIVE
Angiogenesis plays a key role in tumor growth, invasion, and metastasis of cancer diseases, and therefore, the inhibition of angiogenesis can provide an important therapeutic approach in cancer diseases. The aim of this study was to investigate the inhibitory effects of methyl hydroxychalcone on ex vivo sprouting of rat aortic micro-vessels and in vivo formation of chorionic plexus in chick chorioallantoic membrane and to investigate the mechanism underlying anti-angiogenic activity.
METHODS
Rat aortic rings were sectioned by 1 mm. 500μl of 3 mg/ml of fibrinogen in serum free M199 growth medium was added to each well with 5 ug/ml of aprotinin. Methyl hydroxychalcone at varying concentrations ranging from 6.25 µg/ml to 100 µg/ml was added to the complete growth medium. Fertilized chicken eggs were incubated at 37°C. On day 3, a small window was opened in the shell. The window was sealed with adhesive tape and incubated until day 5. One mg of methylhydroxychalcone was applied. Images of each CAM were captured using a digital camera, and the dimensions of the blood vessels were measured digitally. Vascular endothelial growth factor (VEGF)-induced human umbilical vein endothelial cell (HUVEC) proliferation and tube formation assays were examined. Additionally, VEGF-165 levels and expression of membrane VEGF receptor-2 in HUVEC lysates have been assessed.
RESULTS
The data showed that methyl hydroxychalcone significantly had antiangiogenic activity in a dose dependent manner in the rat aorta assay and had significant perturbation activity on blood vessels in the CAM assay. Methyl hydroxychalcone significantly inhibited proliferation and capillary-like tube formation in VEGF-induced HUVEC. Moreover, methylhydroxychalcone significantly reduced VEGF-165 levels in HUVECs lysate.
CONCLUSION
This study showed that methyl hydroxychalcone significantly inhibits the angiogenesis process, blocking the VEGF signaling pathway in HUVECs and could be a potential promising angiogenesis inhibitor lead compound.
Topics: Angiogenesis Inhibitors; Animals; Cell Proliferation; Chickens; Chorioallantoic Membrane; Neovascularization, Pathologic; Rats; Vascular Endothelial Growth Factor A
PubMed: 35763650
DOI: 10.31557/APJCP.2022.23.6.2071 -
Scientific Reports Jun 2016Antithrombin is a key inhibitor of the coagulation cascade, but it may also function as an anti-inflammatory, anti-angiogenic, anti-viral and anti-apoptotic protein....
Antithrombin is a key inhibitor of the coagulation cascade, but it may also function as an anti-inflammatory, anti-angiogenic, anti-viral and anti-apoptotic protein. Here, we report a novel function of antithrombin as a modulator of tumor cell migration and invasion. Antithrombin inhibited enteropeptidase on the membrane surface of HT-29, A549 and U-87 MG cells. The inhibitory process required the activation of antithrombin by heparin, and the reactive center loop and the heparin binding domain were essential. Surprisingly, antithrombin non-covalently inhibited enteropeptidase, revealing a novel mechanism of inhibition for this serpin. Moreover, as a consequence of this inhibition, antithrombin was cleaved, resulting in a molecule with anti-angiogenic properties that reduced vessel-like formation of endothelial cells. The addition of antithrombin and heparin to U-87 MG and A549 cells reduced motility in wound healing assays, inhibited the invasion in transwell assays and the degradation of a gelatin matrix mediated by invadopodia. These processes were controlled by enteropeptidase, as demonstrated by RNA interference experiments. Carcinoma cell xenografts in nude mice showed in vivo co-localization of enteropeptidase and antithrombin. Finally, treatment with heparin reduced experimental metastasis induced by HT29 cells in vivo. In conclusion, the inhibition of enteropeptidase by antithrombin may have a double anti-tumor effect through inhibiting a protease involved in metastasis and generating an anti-angiogenic molecule.
Topics: A549 Cells; Angiogenesis Inhibitors; Animals; Antithrombins; Cell Movement; Endothelial Cells; Enteropeptidase; HT29 Cells; Humans; Mice; Neoplasm Invasiveness; Neoplasms; Neovascularization, Pathologic; Protein Binding; Protein Conformation
PubMed: 27270881
DOI: 10.1038/srep27544 -
International Journal of Molecular... May 2023The high vascularization of glioma highlights the potential value of anti-angiogenic therapeutics for glioma treatment. Previously, we designed a novel...
The high vascularization of glioma highlights the potential value of anti-angiogenic therapeutics for glioma treatment. Previously, we designed a novel vascular-targeting and blood-brain barrier (BBB)-penetrating peptide, TAT-AT7, by attaching the cell-penetrating peptide TAT to a vascular-targeting peptide AT7, and we demonstrated that TAT-AT7 could target binding to the vascular endothelial growth factor receptor 2 (VEGFR-2) and Neuropilin-1 (NRP-1), which are both highly expressed in endothelial cells. TAT-AT7 has been proven to be a good targeting peptide which could effectively deliver the secretory endostatin gene to treat glioma via the TAT-AT7-modified polyethyleneimine (PEI) nanocomplex. In the current study, we further explored the molecular binding mechanisms of TAT-AT7 to VEGFR-2 and NRP-1 and its anti-glioma effects. Accordingly, TAT-AT7 was proven to competitively bind to VEGFR-2 and NRP-1 and prevent VEGF-A165 binding to the receptors by the surface plasmon resonance (SPR) assay. TAT-AT7 inhibited endothelial cells' proliferation, migration, invasion, and tubule formation, as well as promoted endothelial cells' apoptosis in vitro. Further research revealed that TAT-AT7 inhibited the phosphorylation of VEGFR-2 and its downstream PLC-γ, ERK1/2, SRC, AKT, and FAK kinases. Additionally, TAT-AT7 significantly inhibited angiogenesis of zebrafish embryo. Moreover, TAT-AT7 had a better penetrating ability and could penetrate the BBB into glioma tissue and target glioma neovascularization in an orthotopic U87-glioma-bearing nude mice model, and exhibited the effect of inhibiting glioma growth and angiogenesis. Taken together, the binding and function mechanisms of TAT-AT7 were firstly revealed, and TAT-AT7 was proven to be an effective and promising peptide for the development of anti-angiogenic drugs for targeted treatment of glioma.
Topics: Mice; Animals; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factor Receptor-2; Endothelial Cells; Zebrafish; Blood-Brain Barrier; Mice, Nude; Peptides; Glioma; Neovascularization, Pathologic; Angiogenesis Inhibitors; Cell Line, Tumor
PubMed: 37240099
DOI: 10.3390/ijms24108753 -
Recent Patents on Anti-cancer Drug... 2018Massive vessel recruitment is required to sustain rapid tumor growth by delivering oxygen and nutrients. Current strategies to counteract angiogenesis are mostly aimed... (Review)
Review
BACKGROUND
Massive vessel recruitment is required to sustain rapid tumor growth by delivering oxygen and nutrients. Current strategies to counteract angiogenesis are mostly aimed at reducing tumor vessel density. However, many of these drugs have been shown to trigger hypoxia, thus exacerbating tumor aggressiveness. Promising results come from a completely different approach based on the "normalization" of the endothelial layer and the consequent improvement of the vascular function. This new strategy would ameliorate drug delivery to the tumor meanwhile reducing invasiveness and metastatisation.
OBJECTIVE
Since endothelial metabolism has proved essential in the regulation of the angiogenic switch, many recent patents focus on agents able to inhibit specific metabolic pathways in Tumor- Associated Endothelial Cells (TECs) in order to provide vessel normalization. Here, we provide a review of the recent advances in the development of patents on agents targeting endothelial metabolism that have proved effective in several vascular disorders.
METHODS
Results of genetic and pharmacologic studies that brought to the development of patents for methods to counteract aberrant angiogenesis were analysed and sub-divided according to the specific metabolic pathway targeted.
RESULTS
Growing evidences indicate that targeting specific molecular players involved in the endothelial metabolic remodelling required to sustain aberrant angiogenesis, is a valuable therapeutic strategy that can be exploited in vascular disorders as well as in tumor angiogenesis.
CONCLUSION
These findings might have important implications in clinics and could be particularly relevant to patients developing resistance to traditional anti-angiogenic drugs.
Topics: Angiogenesis Inhibitors; Animals; Drug Delivery Systems; Humans; Neoplasms; Neovascularization, Pathologic; Patents as Topic
PubMed: 29807523
DOI: 10.2174/1574892813666180528105023 -
Experimental Eye Research Dec 2014Natural products are characterized by high chemical diversity and biochemical specificity; therefore, they are appealing as lead compounds for drug discovery. Given the... (Review)
Review
Natural products are characterized by high chemical diversity and biochemical specificity; therefore, they are appealing as lead compounds for drug discovery. Given the importance of angiogenesis to many pathologies, numerous natural products have been explored as potential anti-angiogenic drugs. Ocular angiogenesis underlies blinding eye diseases such as retinopathy of prematurity (ROP) in children, proliferative diabetic retinopathy (DR) in adults of working age, and age-related macular degeneration (AMD) in the elderly. Despite the presence of effective therapy in many cases, these diseases are still a significant health burden. Anti-VEGF biologics are the standard of care, but may cause ocular or systemic side effects after intraocular administration and patients may be refractory. Many anti-angiogenic compounds inhibit tumor growth and metastasis alone or in combination therapy, but a more select subset of them has been tested in the context of ocular neovascular diseases. Here, we review the promise of natural products as anti-angiogenic agents, with a specific focus on retinal and choroidal neovascularization. The multifunctional curcumin and the chalcone isoliquiritigenin have demonstrated promising anti-angiogenic effects in mouse models of DR and choroidal neovascularization (CNV) respectively. The homoisoflavanone cremastranone and the flavonoid deguelin have been shown to inhibit ocular neovascularization in more than one disease model. The isoflavone genistein and the flavone apigenin on the other hand are showing potential in the prevention of retinal and choroidal angiogenesis with long-term administration. Many other products with anti-angiogenic potential in vitro such as the lactone withaferin A, the flavonol quercetin, and the stilbenoid combretastatin A4 are awaiting investigation in different ocular disease-relevant animal models. These natural products may serve as lead compounds for the design of more specific, efficacious, and affordable drugs with minimal side effects.
Topics: Angiogenesis Inhibitors; Animals; Biological Products; Eye Diseases; Humans; Neovascularization, Pathologic
PubMed: 25304218
DOI: 10.1016/j.exer.2014.10.002 -
British Journal of Pharmacology Jan 2015Opioid systems mainly regulate physiological functions such as pain, emotional tone and reward circuitry in neural tissues (brain and spinal cord). These systems are... (Review)
Review
UNLABELLED
Opioid systems mainly regulate physiological functions such as pain, emotional tone and reward circuitry in neural tissues (brain and spinal cord). These systems are also found in extraneural tissues (ganglia, gut, spleen, stomach, lung, pancreas, liver, heart, blood and blood vessels), and recent studies have elucidated their roles in various organs. The current review focuses on the roles of opioid systems in blood vessels, especially angiogenesis, during development and tumour malignancy. The balance between endogenous activators and inhibitors of angiogenesis delicately maintains a normally quiescent vasculature to sustain homeostasis. Disturbance of this balance causes pathogenic angiogenesis and, especially in tumours, several activators such as VEGF are highly expressed in the tumour microenvironment and strongly induce tumour angiogenesis, the so-called angiogenic switch. Recently, we demonstrated that κ opioid receptor agonists function as anti-angiogenic factors, which impede the angiogenic switch, in vascular development and tumour angiogenesis by inhibiting the expression of receptors for VEGF. In clinical medicine, angiogenesis inhibitors that target VEGF signalling such as bevacizumab are used as anti-cancer drugs. Although therapies that inhibit tumour angiogenesis have been highly successful for tumour therapy, most patients eventually develop resistance to this anti-angiogenic therapy. Thus, we must identify novel targets for anti-angiogenic agents to sustain inhibition of angiogenesis for tumour therapy. The regulation of responses to κ opioid receptor ligands could be useful for controlling vascular formation under physiological conditions and in cancers, and thus could offer therapeutic benefits beyond the relief of pain.
LINKED ARTICLES
This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.
Topics: Angiogenesis Inhibitors; Animals; Humans; Ligands; Neoplasms; Neovascularization, Pathologic; Neovascularization, Physiologic; Receptors, Opioid, kappa
PubMed: 24417697
DOI: 10.1111/bph.12573 -
221S-1a inhibits endothelial proliferation in pathological angiogenesis through ERK/c-Myc signaling.European Journal of Pharmacology Aug 2023Pathological angiogenesis plays a major role in many disease processes, including cancer and diabetic retinopathy. Antiangiogenic therapy is a potential management for...
Pathological angiogenesis plays a major role in many disease processes, including cancer and diabetic retinopathy. Antiangiogenic therapy is a potential management for pathologic angiogenesis. The novel synthetic compound 221S-1a, derived from captopril, tanshinol and borneol, may have antiangiogenic properties. On the basis of MS, NMR and HPLC analysis, the structure of 221S-1a was identified. The cellular uptake and metabolism of this compound was also observed. Next, the antiangiogenic properties of 221S-1a were evaluated in tumor-xenograft and OIR models in vivo. The inhibitory properties of 221S-1a on endothelial cell proliferation, migration, tube formation and sprouting were detected in vitro. Furthermore, 221S-1a induced G1/S phase arrest was detected by PI staining flow cytometry analysis and Cyclin D, Cyclin E expression. 221S-1a inhibited ERK1/2 activation and nuclear translocation, in addition to downregulation of c-Myc, a transcription factor that regulates cell cycle progression. Molecular docking indicated the interaction of 221S-1a with the ATP-binding site of ERK2, leading to the inhibition of ERK2 phosphorylation and a concomitant inhibition of ERK1 phosphorylation. In conclusion, 221S-1a inhibited the G1/S phase transition by blocking the ERK1/2/c-Myc pathway to reduce tumor and OIR retinal angiogenesis. These novel findings suggest that 221S-1a is a potential pharmacologic candidate for treating pathological angiogenesis.
Topics: Humans; Signal Transduction; Proto-Oncogene Proteins c-myc; Molecular Docking Simulation; Neovascularization, Pathologic; Cell Proliferation
PubMed: 37247812
DOI: 10.1016/j.ejphar.2023.175805