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1.
Article in English | MEDLINE | ID: mdl-29867060

ABSTRACT

No previous studies have evaluated arts based recovery college courses. Yet arts may assist in personal recovery, as often defined by service users, through social connection and personal meaning. This interdisciplinary study evaluated (i) whether self-reported wellbeing and arts activities increased following arts based recovery college courses, and (ii) how students, peer trainers and artist-trainers understood courses' impact. The design was mixed-methods. Of 42 service user students enrolling, 39 completed a course and 37 consented to provide data. Of these, 14 completed pre and post course questionnaires on mental wellbeing and 28 on arts participation. Post course focus groups were held with six of eight peer trainers and five of seven artist-trainers, and 28 students gave written feedback. Twenty-four students were interviewed up to three times in the subsequent nine months. There were statistically significant increases in self-reported mental wellbeing and range of arts activities following course attendance. At follow-up 17 of 24 students reported improved mental wellbeing, while seven reported little or no change. Some spoke of increased social inclusion and continuing to use skills learned in the course to maintain wellbeing. Initial in-course experience of 'artistic growth' predicted follow-up reports of improvement. Future controlled studies should employ standardized measures of social inclusion and arts participation.


Subject(s)
Art Therapy/methods , Mental Disorders/rehabilitation , Psychiatric Rehabilitation/methods , Students/psychology , Adult , Curriculum , Female , Humans , Male , Peer Group , Surveys and Questionnaires , United Kingdom , Universities , Young Adult
2.
Mol Cancer Res ; 15(11): 1608-1622, 2017 11.
Article in English | MEDLINE | ID: mdl-28765266

ABSTRACT

ADAM12, (ADisintegrin and metalloproteinase domain-containing protein 12), is upregulated in epithelial cancers and contributes to increased tumor proliferation, metastasis, and endocrine resistance. However, its role in tumor angiogenesis is unknown. Here, we report that ADAM12 is upregulated in the vessels of aggressive breast tumors and exerts key regulatory functions. ADAM12 significantly increases bFGF-mediated angiogenesis in vivo and ADAM12 levels are upregulated in tumors that have undergone a switch to the angiogenic phenotype. Importantly, ADAM12-overexpressing breast tumors display a higher microvessel density (MVD). Our goal was to identify the mechanisms by which tumor-associated ADAM12 promotes angiogenesis. ADAM12 expression in breast tumor cells correlated with a significant upregulation of proangiogenic factors such as VEGF and MMP-9 and downregulation of antiangiogenic factors such as Thrombospondin-1 (THBS1/TSP1) and Tissue Inhibitor of Metalloproteinases-2 (TIMP-2). Co-culture with ADAM12-expressing tumor cells promoted endothelial cell (EC) recruitment and capillary tube formation. Conversely, downregulation of endogenous ADAM12 in breast cancer cell lines resulted in reduction of pro-angiogenic factors and EC recruitment. These ADAM12-mediated effects are driven by the activation of EGFR, STAT3 and Akt signaling. Blockade of EGFR/STAT3 or silencing of ADAM12 reversed the proangiogenic tumor phenotype, significantly downregulated pro-angiogenic mitogens and reduced EC recruitment. In human breast cancer tissues, ADAM12 expression was significantly positively correlated with pro-angiogenic factors including VEGF and MMP-9 but negatively associated with TSP1.Implications: These novel findings suggest that ADAM12 regulates EC function and facilitates a proangiogenic microenvironment in a STAT3-dependent manner. A combined approach of targeting ADAM12 and STAT3 signaling in breast cancer may represent a promising strategy to inhibit tumor neovascularization. Mol Cancer Res; 15(11); 1608-22. ©2017 AACR.


Subject(s)
ADAM12 Protein/genetics , ADAM12 Protein/metabolism , Breast Neoplasms/metabolism , Neovascularization, Pathologic/metabolism , STAT3 Transcription Factor/metabolism , Up-Regulation , Animals , Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/metabolism , Breast Neoplasms/genetics , Cell Line, Tumor , Female , Fibroblast Growth Factor 2/pharmacology , Gene Expression Regulation, Neoplastic , Humans , MCF-7 Cells , Matrix Metalloproteinase 9/metabolism , Mice , Neoplasm Transplantation , Neovascularization, Pathologic/genetics , Signal Transduction , Vascular Endothelial Growth Factor A/metabolism
3.
Proc Natl Acad Sci U S A ; 110(33): 13528-33, 2013 Aug 13.
Article in English | MEDLINE | ID: mdl-23898174

ABSTRACT

Epoxyeicosatrienoic acids (EETs), lipid mediators produced by cytochrome P450 epoxygenases, regulate inflammation, angiogenesis, and vascular tone. Despite pleiotropic effects on cells, the role of these epoxyeicosanoids in normal organ and tissue regeneration remains unknown. EETs are produced predominantly in the endothelium. Normal organ and tissue regeneration require an active paracrine role of the microvascular endothelium, which in turn depends on angiogenic growth factors. Thus, we hypothesize that endothelial cells stimulate organ and tissue regeneration via production of bioactive EETs. To determine whether endothelial-derived EETs affect physiologic tissue growth in vivo, we used genetic and pharmacological tools to manipulate endogenous EET levels. We show that endothelial-derived EETs play a critical role in accelerating tissue growth in vivo, including liver regeneration, kidney compensatory growth, lung compensatory growth, wound healing, corneal neovascularization, and retinal vascularization. Administration of synthetic EETs recapitulated these results, whereas lowering EET levels, either genetically or pharmacologically, delayed tissue regeneration, demonstrating that pharmacological modulation of EETs can affect normal organ and tissue growth. We also show that soluble epoxide hydrolase inhibitors, which elevate endogenous EET levels, promote liver and lung regeneration. Thus, our observations indicate a central role for EETs in organ and tissue regeneration and their contribution to tissue homeostasis.


Subject(s)
Eicosanoids/pharmacology , Endothelial Cells/metabolism , Epoxy Compounds/pharmacology , Neovascularization, Physiologic/physiology , Regeneration/physiology , Animals , Chromatography, Liquid , Eicosanoids/metabolism , Epoxide Hydrolases/antagonists & inhibitors , Epoxy Compounds/metabolism , Eye/blood supply , Immunohistochemistry , Kidney/physiology , Liver/physiology , Lung/physiology , Mice , Mice, Transgenic , Neovascularization, Physiologic/drug effects , Receptor, TIE-2/genetics , Regeneration/drug effects , Tandem Mass Spectrometry
4.
FASEB J ; 27(1): 45-50, 2013 Jan.
Article in English | MEDLINE | ID: mdl-22982376

ABSTRACT

Lipocalin 2 (Lcn2), a member of the lipocalin family, is up-regulated in a variety of epithelial cancers. We have previously reported that Lcn2 induces the epithelial to mesenchymal transition in breast cancer through the estrogen receptor α/Slug axis and that it is a potential noninvasive biomarker of this disease. Here, we report the novel finding that Lcn2 regulates breast cancer angiogenesis. Vascular endothelial growth factor (VEGF), a key angiogenic activator, was significantly increased with Lcn2 expression in MCF-7 human breast cancer cells as well as in an angiogenic line derived from MDA-MB-436 cells. Treatment with a VEGF-neutralizing antibody demonstrates that VEGF is essential for the angiogenic activity of Lcn2. We further demonstrate that Lcn2-induced VEGF is mediated through hypoxia-inducible factor 1α (HIF-1α) and that Lcn2 regulates HIF-1α through extracellular signal-regulated kinase (Erk). The regulation of HIF-1α and VEGF by Lcn2 was also demonstrated in the aggressive MDA-MB-231 cell line. Using the mouse corneal pocket assay, we found that Lcn2 significantly enhanced the angiogenesis induced by VEGF. Taken together, these results are the first to demonstrate that Lcn2 promotes angiogenesis in vitro and in vivo and suggest a novel mechanism through which Lcn2 may promote tumor progression.


Subject(s)
Breast Neoplasms/blood supply , Lipocalins/physiology , Neovascularization, Pathologic/physiopathology , Base Sequence , Cell Line, Tumor , DNA Primers , Female , Humans , Hypoxia-Inducible Factor 1, alpha Subunit/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Up-Regulation/physiology , Vascular Endothelial Growth Factor A/metabolism
5.
Pediatr Res ; 71(2): 168-78, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22258128

ABSTRACT

INTRODUCTION: We investigated the use of dietary omega-3 (ω-3) polyunsaturated fatty acids (PUFAs) in the treatment of neuroblastoma both as a sole agent and in combination with sunitinib, a broad-spectrum tyrosine kinase receptor inhibitor. RESULTS: Substitution of all dietary fat with menhaden oil (ω-3 PUFA rich) resulted in a 40-70% inhibition of tumor growth and a statistically significant difference in the levels of several PUFAs (18:2 ω-6, 20:4 ω-6, 22:4 ω-6, 20:5 ω-3) as compared with a control diet. Furthermore, tumors from animals on the ω-3 fatty acid (FA)-enriched diet had an elevated triene/tetraene ratio suggestive of a change in local eicosanoid metabolism in these tissues similar to that seen with essential fatty acid deficiency. The ω-3 FA-enriched diet also decreased tumor-associated inflammatory cells and induced mitochondrial changes suggestive of mitochondrial damage. Combination treatment with sunitinib resulted in further reduction in tumor proliferation and microvessel density. DISCUSSION: These findings suggest a potential role for ω-3 PUFAs in the combination treatment of neuroblastoma. METHODS: We used a murine model of orthotopic and subcutaneous human neuroblastoma and diets that differ in the FA content to define the optimal dietary ω-3/omega-6 (ω-6) FA ratio required for the inhibition of these tumors.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Cell Proliferation/drug effects , Diet , Fatty Acids, Omega-3/administration & dosage , Fish Oils/administration & dosage , Indoles/pharmacology , Neuroblastoma/diet therapy , Neuroblastoma/drug therapy , Protein Kinase Inhibitors/pharmacology , Pyrroles/pharmacology , Animals , Arachidonic Acid/metabolism , Cell Line, Tumor , Dose-Response Relationship, Drug , Fatty Acids, Omega-3/metabolism , Fish Oils/metabolism , Humans , Lipid Metabolism , Male , Mice , Mice, SCID , Microvessels/drug effects , Microvessels/pathology , Mitochondria/drug effects , Mitochondria/pathology , Neuroblastoma/blood supply , Neuroblastoma/enzymology , Neuroblastoma/pathology , Sunitinib , Time Factors , Tumor Burden/drug effects , Xenograft Model Antitumor Assays
6.
J Clin Invest ; 122(1): 178-91, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22182838

ABSTRACT

Epoxyeicosatrienoic acids (EETs) are small molecules produced by cytochrome P450 epoxygenases. They are lipid mediators that act as autocrine or paracrine factors to regulate inflammation and vascular tone. As a result, drugs that raise EET levels are in clinical trials for the treatment of hypertension and many other diseases. However, despite their pleiotropic effects on cells, little is known about the role of these epoxyeicosanoids in cancer. Here, using genetic and pharmacological manipulation of endogenous EET levels, we demonstrate that EETs are critical for primary tumor growth and metastasis in a variety of mouse models of cancer. Remarkably, we found that EETs stimulated extensive multiorgan metastasis and escape from tumor dormancy in several tumor models. This systemic metastasis was not caused by excessive primary tumor growth but depended on endothelium-derived EETs at the site of metastasis. Administration of synthetic EETs recapitulated these results, while EET antagonists suppressed tumor growth and metastasis, demonstrating in vivo that pharmacological modulation of EETs can affect cancer growth. Furthermore, inhibitors of soluble epoxide hydrolase (sEH), the enzyme that metabolizes EETs, elevated endogenous EET levels and promoted primary tumor growth and metastasis. Thus, our data indicate a central role for EETs in tumorigenesis, offering a mechanistic link between lipid signaling and cancer and emphasizing the critical importance of considering possible effects of EET-modulating drugs on cancer.


Subject(s)
Eicosanoids/metabolism , Neoplasm Metastasis/physiopathology , Neoplasms, Experimental/metabolism , Animals , Aryl Hydrocarbon Hydroxylases/genetics , Aryl Hydrocarbon Hydroxylases/metabolism , Cytochrome P-450 CYP2C8 , Cytochrome P-450 CYP2J2 , Cytochrome P-450 Enzyme Inhibitors , Cytochrome P-450 Enzyme System/genetics , Cytochrome P-450 Enzyme System/metabolism , Endothelium, Vascular/metabolism , Epoxy Compounds/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Neoplasm Metastasis/pathology , Neoplasms, Experimental/blood supply , Neoplasms, Experimental/pathology , Neovascularization, Pathologic , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Vascular Endothelial Growth Factor A/metabolism
7.
Biochem Biophys Res Commun ; 409(3): 562-6, 2011 Jun 10.
Article in English | MEDLINE | ID: mdl-21605550

ABSTRACT

An angiogenesis inhibitor named Beta-35 has been identified and purified from the conditioned medium of mouse pancreatic ß cells tumor cells. Beta-35 has a molecular weight of 35 kDa and inhibits DNA synthesis of bovine capillary endothelial cells at a half-maximal concentration of approximately 5 nM. It shows anti-angiogenic activity in the chick embryo chorioallantoic membrane at a dose of about 1 µg/embryo. Amino acid microsequencing and mass spectrometric analysis of the purified protein demonstrate that Beta-35 contains the first 314 residues of the N-terminal sequence of bovine transferrin. We have cloned and expressed this protein in Escherichia coli using the corresponding gene segment of Beta-35 contained in the cDNA of human transferrin. The recombinant protein of Beta-35 shows significant anti-tumor activity at a dose of 5mg/kg/day against human pancreatic cancer or melanoma implanted subcutaneously in SCID mice.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Neoplasms/blood supply , Neoplasms/drug therapy , Peptide Fragments/therapeutic use , Transferrin/therapeutic use , Amino Acid Sequence , Angiogenesis Inhibitors/genetics , Angiogenesis Inhibitors/isolation & purification , Animals , Cattle , Cell Line, Tumor , Cloning, Molecular , Culture Media, Conditioned/chemistry , Culture Media, Conditioned/pharmacology , Humans , Melanoma/blood supply , Melanoma/drug therapy , Mice , Mice, SCID , Molecular Sequence Data , Neoplasm Transplantation , Pancreatic Neoplasms/metabolism , Peptide Fragments/genetics , Peptide Fragments/isolation & purification , Recombinant Proteins/genetics , Recombinant Proteins/therapeutic use , Transferrin/genetics , Transferrin/isolation & purification
8.
J Clin Invest ; 121(5): 1894-904, 2011 May.
Article in English | MEDLINE | ID: mdl-21505261

ABSTRACT

The epicardium makes essential cellular and paracrine contributions to the growth of the fetal myocardium and the formation of the coronary vasculature. However, whether the epicardium has similar roles postnatally in the normal and injured heart remains enigmatic. Here, we have investigated this question using genetic fate-mapping approaches in mice. In uninjured postnatal heart, epicardial cells were quiescent. Myocardial infarction increased epicardial cell proliferation and stimulated formation of epicardium-derived cells (EPDCs), which remained in a thickened layer on the surface of the heart. EPDCs did not adopt cardiomyocyte or coronary EC fates, but rather differentiated into mesenchymal cells expressing fibroblast and smooth muscle cell markers. In vitro and in vivo assays demonstrated that EPDCs secreted paracrine factors that strongly promoted angiogenesis. In a myocardial infarction model, EPDC-conditioned medium reduced infarct size and improved heart function. Our findings indicate that epicardium modulates the cardiac injury response by conditioning the subepicardial environment, potentially offering a new therapeutic strategy for cardiac protection.


Subject(s)
Myocardium/pathology , Myocytes, Cardiac/metabolism , Pericardium/metabolism , Animals , Fibroblasts/metabolism , Heart/physiology , Heart Injuries/metabolism , Homeostasis , Intercellular Signaling Peptides and Proteins/metabolism , Mice , Models, Biological , Models, Genetic , Myocardial Infarction/pathology , Myocardium/metabolism , Neovascularization, Pathologic , Treatment Outcome
9.
Int Health ; 2(3): 165-71, 2010 Sep.
Article in English | MEDLINE | ID: mdl-24037696

ABSTRACT

The need to strengthen health capacity in developing countries is widely documented. The World Health Organization has called for an increase in the number of health workers in all countries experiencing critical shortages, a significant scaling-up of training and more efficient use of existing health workers. Health Links, long-term mutually beneficial partnerships between UK health institutions and their counterparts in developing countries, are helping to fill these gaps. Links allow for the reciprocal transfer of knowledge and skills between partners, enabling the UK's expertise in health service delivery and training to be channelled towards the needs of those in developing countries, while also bringing a wide range of benefits to the UK. Examples of Health Links in Ethiopia demonstrate such benefits. An increasingly supportive policy environment is enabling a significant expansion in the number of Links. However, the quality of these Links is critical to their impact and thus there is a need both to continue to support those engaging in Links to develop sustainable, mutually beneficial strategic partnerships, and to strengthen the body of evidence of their impacts.

10.
Exp Ther Med ; 1(5): 739-746, 2010 Sep.
Article in English | MEDLINE | ID: mdl-22993597

ABSTRACT

The chemotherapeutic agent etoposide is a topoisomerase II inhibitor widely used for cancer therapy. Low-dose oral etoposide, administered at close regular intervals, has potent anti-tumor activity in patients who are refractory to intravenous etoposide; however, the mechanism remains unclear. Since endothelial cells may be more sensitive than tumor cells to chemotherapy agents, we determined the effects of etoposide alone and in combination with oral cyclooxygenase-2 inhibitors and peroxisome-proliferator activated receptor γ ligands on angiogenesis and tumor growth in xenograft tumor models. Optimal anti-angiogenic (metronomic) and anti-tumor doses of etoposide on angiogenesis, primary tumor growth and metastasis were established alone and in combination therapy. Etoposide inhibited endothelial and tumor cell proliferation, decreased vascular endothelial growth factor (VEGF) production by tumor cells and suppressed endothelial tube formation at non-cytotoxic concentrations. In our in vivo studies, oral etoposide inhibited fibroblast growth factor 2 and VEGF-induced corneal neovascularization, VEGF-induced vascular permeability and increased levels of the endogenous angiogenesis inhibitor endostatin in mice. In addition, etoposide inhibited Lewis lung carcinoma (LLC) and human glioblastoma (U87) primary tumor growth as well as spontaneous lung metastasis in a LLC resection model. Furthermore, etoposide had synergistic anti-tumor activity in combination with celecoxib and rosiglitazone, which are also oral anti-angiogenic and anti-tumor agents. Etoposide inhibits angiogenesis in vitro and in vivo by indirect and direct mechanisms of action. Combining etoposide with celecoxib and rosiglitazone increases its efficacy and merits further investigation in future clinical trials to determine the potential usefulness of etoposide in combinatory anti-angiogenic chemotherapy.

12.
Proc Natl Acad Sci U S A ; 105(3): 985-90, 2008 Jan 22.
Article in English | MEDLINE | ID: mdl-18199835

ABSTRACT

Angiogenesis and inflammation are central processes through which the tumor microenvironment influences tumor growth. We have demonstrated recently that peroxisome proliferator-activated receptor (PPAR)alpha deficiency in the host leads to overt inflammation that suppresses angiogenesis via excess production of thrombospondin (TSP)-1 and prevents tumor growth. Hence, we speculated that pharmacologic activation of PPARalpha would promote tumor growth. Surprisingly, the PPARalpha agonist fenofibrate potently suppressed primary tumor growth in mice. This effect was not mediated by cancer-cell-autonomous antiproliferative mechanisms but by the inhibition of angiogenesis and inflammation in the host tissue. Although PPARalpha-deficient tumors were still susceptible to fenofibrate, absence of PPARalpha in the host animal abrogated the potent antitumor effect of fenofibrate. In addition, fenofibrate suppressed endothelial cell proliferation and VEGF production, increased TSP-1 and endostatin, and inhibited corneal neovascularization. Thus, both genetic abrogation of PPARalpha as well as its activation by ligands cause tumor suppression via overlapping antiangiogenic pathways. These findings reveal the potential utility of the well tolerated PPARalpha agonists beyond their use as lipid-lowering drugs in anticancer therapy. Our results provide a mechanistic rationale for evaluating the clinical benefits of PPARalpha agonists in cancer treatment, alone and in combination with other therapies.


Subject(s)
Fenofibrate/pharmacology , Neoplasms/blood supply , Neoplasms/metabolism , PPAR alpha/agonists , Animals , Cell Line, Tumor , Cornea/blood supply , Cornea/drug effects , Cornea/metabolism , Endothelial Cells/metabolism , Endothelium/metabolism , Fenofibrate/therapeutic use , Fibroblast Growth Factor 2/pharmacology , Humans , Ligands , Mice , Mice, Inbred C57BL , Mice, Knockout , Neoplasms/drug therapy , Neoplasms/pathology , PPAR alpha/deficiency , PPAR alpha/genetics , PPAR alpha/metabolism
13.
PLoS One ; 2(2): e260, 2007 Feb 28.
Article in English | MEDLINE | ID: mdl-17327920

ABSTRACT

Inflammation in the tumor bed can either promote or inhibit tumor growth. Peroxisome proliferator-activated receptor (PPAR)alpha is a central transcriptional suppressor of inflammation, and may therefore modulate tumor growth. Here we show that PPARalpha deficiency in the host leads to overt inflammation that suppresses angiogenesis via excess production of the endogenous angiogenesis inhibitor thrombospondin-1 and prevents tumor growth. Bone marrow transplantation and granulocyte depletion show that PPARalpha expressing granulocytes are necessary for tumor growth. Neutralization of thrombospondin-1 restores tumor growth in PPARalpha-deficient mice. These findings suggest that the absence of PPARalpha activity renders inflammatory infiltrates tumor suppressive and, thus, may provide a target for inhibiting tumor growth by modulating stromal processes, such as angiogenesis.


Subject(s)
Granulocytes/physiology , Neoplasm Proteins/physiology , Neoplasms, Experimental/pathology , PPAR alpha/physiology , Animals , Bone Marrow Cells/metabolism , Bone Marrow Transplantation , Carcinoma, Lewis Lung/genetics , Carcinoma, Lewis Lung/pathology , Cell Line, Transformed/transplantation , Corneal Neovascularization/genetics , Inflammation , Male , Melanoma, Experimental/blood supply , Melanoma, Experimental/genetics , Melanoma, Experimental/pathology , Mice , Mice, Knockout , Neoplasm Proteins/genetics , Neoplasms, Experimental/blood supply , Neoplasms, Experimental/genetics , Neovascularization, Pathologic/physiopathology , Neovascularization, Pathologic/prevention & control , PPAR alpha/deficiency , PPAR alpha/genetics , Radiation Chimera , Thrombospondin 1/physiology , Vascular Endothelial Growth Factor A/physiology
14.
Blood ; 109(4): 1524-32, 2007 Feb 15.
Article in English | MEDLINE | ID: mdl-17023588

ABSTRACT

Tetraspanin protein CD151 is abundant on endothelial cells. To determine whether CD151 affects angiogenesis, Cd151-null mice were prepared. Cd151-null mice showed no vascular defects during normal development or during neonatal oxygen-induced retinopathy. However, Cd151-null mice showed impaired pathologic angiogenesis in other in vivo assays (Matrigel plug, corneal micropocket, tumor implantation) and in the ex vivo aortic ring assay. Cd151-null mouse lung endothelial cells (MLECs) showed normal adhesion and proliferation, but marked alterations in vitro, in assays relevant to angiogenesis (migration, spreading, invasion, Matrigel contraction, tube and cable formation, spheroid sprouting). Consistent with these functional impairments, and with the close, preferential association of CD151 with laminin-binding integrins, Cd151-null MLECs also showed selective signaling defects, particularly on laminin substrate. Adhesion-dependent activation of PKB/c-Akt, e-NOS, Rac, and Cdc42 was diminished, but Raf, ERK, p38 MAP kinase, FAK, and Src were unaltered. In Cd151-null MLECs, connections were disrupted between laminin-binding integrins and at least 5 other proteins. In conclusion, CD151 modulates molecular organization of laminin-binding integrins, thereby supporting secondary (ie, after cell adhesion) functions of endothelial cells, which are needed for some types of pathologic angiogenesis in vivo. Selective effects of CD151 on pathologic angiogenesis make it a potentially useful target for anticancer therapy.


Subject(s)
Antigens, CD/physiology , Neovascularization, Pathologic , Animals , Animals, Newborn , Antigens, CD/genetics , Cell Adhesion , Cell Proliferation , Endothelial Cells , Lung/cytology , Mice , Mice, Knockout , Signal Transduction , Tetraspanin 24
15.
Proc Natl Acad Sci U S A ; 103(4): 855-60, 2006 Jan 24.
Article in English | MEDLINE | ID: mdl-16418262

ABSTRACT

Platelets contain both pro- and antiangiogenic factors, but their regulatory role in angiogenesis is poorly understood. Although previous studies showed that platelets stimulate angiogenesis in vitro, the role of platelets in angiogenesis in vivo is largely uncharacterized. To address this topic, we used two in vivo approaches, the cornea micropocket assay and the Matrigel model, in four animal models: thrombocytopenic, Lyst(bg) (platelet storage pool deficiency), glycoprotein (GP) Ibalpha/IL4R transgenic (lacking extracellular GPIbalpha, the receptor for von Willebrand factor as well as other adhesive and procoagulant proteins), and FcgammaR(-/-) (lacking functional GPVI, the collagen receptor) mice. Adult mice were rendered thrombocytopenic by i.p. administration of an antiplatelet antibody. The number of growing vessels in the thrombocytopenic mice was lower in the cornea assay, and they showed significantly increased appearance of hemorrhage compared with mice treated with control IgG. The thrombocytopenic mice also showed more protein leakage and developed hematomas in the Matrigel model. GPIbalpha/IL4R transgenic mice presented increased hemorrhage in both assays, but it was less severe than in the platelet-depleted mice. FcgammaR(-/-) and Lyst(bg) mice showed no defect in experimental angiogenesis. Intravital microscopy revealed a >3-fold increase in platelet adhesion to angiogenic vessels of Matrigel compared with mature quiescent skin vessels. Our results suggest that the presence of platelets not only stimulates angiogenic vessel growth but also plays a critical role in preventing hemorrhage from the angiogenic vessels. The adhesion function of platelets, as mediated by GPIbalpha, significantly contributes to the process.


Subject(s)
Blood Platelets/cytology , Hemorrhage/prevention & control , Platelet Adhesiveness , Animals , Blood Platelets/metabolism , Cell Adhesion , Collagen/chemistry , Collagen/metabolism , Cornea/metabolism , Drug Combinations , Fibroblast Growth Factors/metabolism , Glycoproteins/chemistry , Hemoglobins/metabolism , Laminin/chemistry , Laminin/metabolism , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , Models, Statistical , Neovascularization, Pathologic , Proteoglycans/chemistry , Proteoglycans/metabolism , Thrombocytopenia , Time Factors , Transgenes , von Willebrand Factor/metabolism
16.
Proc Natl Acad Sci U S A ; 101(32): 11658-63, 2004 Aug 10.
Article in English | MEDLINE | ID: mdl-15289610

ABSTRACT

Spatio-temporal studies on the growth of capillary blood vessels and capillary lymphatic vessels in tissue remodeling have suggested that lymphangiogenesis is angiogenesis-dependent. We revisited this concept by using fibroblast growth factor 2 (FGF-2) (80 ng) to stimulate the growth of both vessel types in the mouse cornea. When we lowered the dose of FGF-2 in the cornea 6.4-fold (12.5 ng), the primary response was lymphangiogenic. Further investigation revealed that vascular endothelial growth factor-C and -D are required for this apparent lymphangiogenic property of FGF-2, and when the small amount of accompanying angiogenesis was completely suppressed, lymphangiogenesis remained unaffected. Our findings demonstrate that there is a dose-dependent response of FGF-2 for lymphangiogenesis, and lymphangiogenesis can occur in the absence of a preexisting or developing vascular bed, i.e., in the absence of angiogenesis, in the mouse cornea.


Subject(s)
Fibroblast Growth Factor 2/pharmacology , Lymphangiogenesis/drug effects , Animals , Cell Division/drug effects , Cell Movement/drug effects , Cornea/blood supply , Cornea/physiology , Corneal Neovascularization , Dose-Response Relationship, Drug , Endothelial Cells/cytology , Endothelial Cells/drug effects , Male , Mice , Mice, Inbred Strains , Neovascularization, Physiologic/drug effects , Vascular Endothelial Growth Factor C/pharmacology , Vascular Endothelial Growth Factor D/pharmacology
17.
Bioorg Med Chem Lett ; 14(2): 421-5, 2004 Jan 19.
Article in English | MEDLINE | ID: mdl-14698173

ABSTRACT

The synthesis of a tris(hydroxymethyl)acrylamidomethane (THAM)-derived cotelomer endowed with thalidomide units and a preliminary assessment of its biological activity are described. 4-Carboxy thalidomide and 4-(N-acryloyl) lysine thalidomide derivatives were prepared. The polymerization of these compounds with THAM in the presence of octanethiol as transfer reagent provided a water-soluble telomer bearing several thalidomide units. The ability of this telomer to inhibit angiogenesis in a mouse model of corneal neovascularization was compared to 4-carboxy thalidomide and thalidomide. A significant inhibition in area of neovascularization stimulated by a bFGF pellet was observed only in the mice treated with the telomer.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Neovascularization, Physiologic/drug effects , Thalidomide/pharmacology , Tromethamine/pharmacology , Allantois/blood supply , Allantois/drug effects , Angiogenesis Inhibitors/chemical synthesis , Animals , Cattle , Chick Embryo , Chorion/blood supply , Chorion/drug effects , Cornea/blood supply , Cornea/drug effects , Male , Mice , Mice, Inbred C57BL , Neovascularization, Physiologic/physiology , Thalidomide/chemical synthesis , Tromethamine/chemical synthesis
18.
J Biol Chem ; 278(42): 40989-95, 2003 Oct 17.
Article in English | MEDLINE | ID: mdl-12900406

ABSTRACT

Tissue inhibitors of metalloproteinases (TIMPs) regulate tumor growth, progression, and angiogenesis in a variety of experimental cancer models and in human malignancies. Results from numerous studies have revealed important differences between TIMP family members in their ability to inhibit angiogenic processes in vitro and angiogenesis in vivo despite their universal ability to inhibit matrix metalloproteinase (MMP) activity. To address these differences, a series of structure-function studies were conducted to identify and to characterize the anti-angiogenic domains of TIMP-2, the endogenous MMP inhibitor that uniquely inhibits capillary endothelial cell (EC) proliferation as well as angiogenesis in vivo. We demonstrate that the COOH-terminal domain of TIMP-2 (T2C) inhibits the proliferation of capillary EC at molar concentrations comparable with those previously reported for intact TIMP-2, while the NH2-terminal domain (T2N), which inhibits MMP activity, has no significant anti-proliferative effect. Interestingly, although both T2N and T2C inhibited embryonic angiogenesis, only T2C resulted in the potent inhibition of angiogenesis driven by the exogenous addition of angiogenic mitogen, suggesting that MMP inhibition alone may not be sufficient to inhibit the aggressive neovascularization characteristic of aberrant angiogenesis. We further mapped the anti-proliferative activity of T2C to a 24-amino acid peptide corresponding to Loop 6 of TIMP-2 and show that Loop 6 is a potent inhibitor of both embryonic and mitogen-stimulated angiogenesis in vivo. These findings demonstrate that TIMP-2 possesses two distinct types of anti-angiogenic activities which can be uncoupled from each other, the first represented by its MMP-dependent inhibitory activity which can inhibit only embryonic neovascularization and the second represented by an MMP-independent activity which inhibits both normal angiogenesis and mitogen-driven angiogenesis in vivo. In addition, we report, for the first time, the discovery of Loop 6 as a novel and potent inhibitor of angiogenesis.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Tissue Inhibitor of Metalloproteinase-2/metabolism , Tissue Inhibitor of Metalloproteinase-2/physiology , Amino Acid Sequence , Animals , Cattle , Cells, Cultured , Cloning, Molecular , DNA, Complementary/metabolism , Dose-Response Relationship, Drug , Endothelium, Vascular/cytology , Gene Library , Humans , Inhibitory Concentration 50 , Mice , Molecular Sequence Data , Protein Structure, Tertiary , Recombinant Proteins/metabolism , Sequence Homology, Amino Acid , Time Factors , Tissue Inhibitor of Metalloproteinase-2/chemistry
19.
Proc Natl Acad Sci U S A ; 100(8): 4736-41, 2003 Apr 15.
Article in English | MEDLINE | ID: mdl-12682294

ABSTRACT

Plaque angiogenesis promotes the growth of atheromas, but the functions of plaque capillaries are not fully determined. Neovascularization may act as a conduit for the entry of leukocytes into sites of chronic inflammation. We observe vasa vasorum density correlates highly with the extent of inflammatory cells, not the size of atheromas in apolipoprotein E-deficient mice. We show atherosclerotic aortas contain activities that promote angiogenesis. The angiogenesis inhibitor angiostatin reduces plaque angiogenesis and inhibits atherosclerosis. Macrophages in the plaque and around vasa vasorum are reduced, but we detect no direct effect of angiostatin on monocytes. After angiogenesis blockade in vivo, the angiogenic potential of atherosclerotic tissue is suppressed. Activated macrophages stimulate angiogenesis that can further recruit inflammatory cells and more angiogenesis. Our findings demonstrate that late-stage inhibition of angiogenesis can interrupt this positive feedback cycle. Inhibition of plaque angiogenesis and the secondary reduction of macrophages may have beneficial effects on plaque stability.


Subject(s)
Arteriosclerosis/pathology , Arteriosclerosis/prevention & control , Macrophages/pathology , Neovascularization, Pathologic/prevention & control , Angiostatins , Animals , Apolipoproteins E/deficiency , Apolipoproteins E/genetics , Arteriosclerosis/etiology , Chemokine CCL2/biosynthesis , Endothelial Growth Factors/biosynthesis , Endothelial Growth Factors/pharmacology , Feedback , In Vitro Techniques , Inflammation/pathology , Intercellular Signaling Peptides and Proteins/biosynthesis , Intercellular Signaling Peptides and Proteins/pharmacology , Lymphokines/biosynthesis , Lymphokines/pharmacology , Macrophages/drug effects , Mice , Mice, Inbred C57BL , Mice, Knockout , Monocytes/drug effects , Monocytes/pathology , Peptide Fragments/biosynthesis , Peptide Fragments/pharmacology , Plasminogen/biosynthesis , Plasminogen/pharmacology , Receptors, LDL/deficiency , Receptors, LDL/genetics , Vasa Vasorum/pathology , Vascular Endothelial Growth Factor A , Vascular Endothelial Growth Factors
20.
J Clin Invest ; 110(7): 923-32, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12370270

ABSTRACT

Several drugs approved for a variety of indications have been shown to exhibit antiangiogenic effects. Our study focuses on the PPARgamma ligand rosiglitazone, a compound widely used in the treatment of type 2 diabetes. We demonstrate, for the first time to our knowledge, that PPARgamma is highly expressed in tumor endothelium and is activated by rosiglitazone in cultured endothelial cells. Furthermore, we show that rosiglitazone suppresses primary tumor growth and metastasis by both direct and indirect antiangiogenic effects. Rosiglitazone inhibits bovine capillary endothelial cell but not tumor cell proliferation at low doses in vitro and decreases VEGF production by tumor cells. In our in vivo studies, rosiglitazone suppresses angiogenesis in the chick chorioallantoic membrane, in the avascular cornea, and in a variety of primary tumors. These results suggest that PPARgamma ligands may be useful in treating angiogenic diseases such as cancer by inhibiting angiogenesis.


Subject(s)
Angiogenesis Inhibitors/pharmacology , Antineoplastic Agents/pharmacology , Neoplasm Metastasis/prevention & control , Receptors, Cytoplasmic and Nuclear/physiology , Thiazoles/pharmacology , Thiazolidinediones , Transcription Factors/physiology , Animals , Cattle , Fibroblast Growth Factor 2/physiology , Humans , Ligands , Neoplasm Invasiveness
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