Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P39060 (endostatin)
 2,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To isolate matrix molecules with angiogenic activity, tumor extracellular matrix (ECM) fractions from the basement membrane preparation Matrigel were analyzed for effects on endothelial cell (EC) proliferation, differentiation, and vessel formation in vivo. Inhibition of human and bovine EC DNA synthesis was evident upon treatment with several soluble Matrigel fractions including conditioned media (MGCM). After size fractionation of MGCM, EC growth arrest was activated by factor(s) smaller than 3,000 daltons (3KF). Bovine EC differentiation (tube formation) was promoted by both MGCM and 3KF fractions in two different models using matrigel or collagen gels to stimulate tube formation. The 3KF factor(s) stimulated angiogenesis when implanted in the cornea or subcutaneously in mice. FGF-induced angiogenesis and blood flow were increased in the presence of 3KF factor(s), an effect that was inhibited by the anti-angiogenic molecule endostatin. Further characterization of the low molecular weight 3KF samples by RP-HPLC revealed several fractions exhibiting EC growth arrest activity. These results suggest that the ability of ECM preparations to induce EC growth arrest and tube formation may reside, at least partially, in previously undetected low molecular weight molecules. Characterization of these ECM-associated inhibitors may lead to the development of novel anti-angiogenic and anti-tumor compounds.
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PMID:Extracellular matrix-derived angiogenic factor(s) inhibit endothelial cell proliferation, enhance differentiation, and stimulate angiogenesis in vivo. 1182 74

Angiogenesis is a vital component of the development and progression of many human solid tumors. Glioblastoma multiforme is one of the most highly vascularised class of solid tumors. Thus, we have investigated the potential antitumourigenic activity of endostatin, an angiogenic inhibitor, in the rat C6 glioma model. We have engineered C6 cells that endogenously express mouse endostatin in order to assess the growth of C6 tumors in vivo when endostatin is constitutively expressed. Endostatin secreted by stably transfected C6 cells is biologically active as shown by its inhibition (26%) of bFGF-stimulated proliferation of BAECs in culture. The subcutaneous implantation of endostatin-C6 cells in athymic (nu/nu) mice resulted in a reduced tumor growth rate (90% inhibition) compared to control cell lines throughout the duration of our experiments. Tumor inhibition was associated with a 50% reduction in the number of vessels, which were also smaller in morphology. However, endostatin-C6 tumors were no more necrotic than control tumors. The implantation of endostatin-C6 cells into immunocompetent Wistar rat brains also resulted in reduced tumor volumes (71% inhibition) compared to controls. Tumor cells were sparsely localised along the injection tract but had not formed discrete tumors. Despite the inhibitory response mediated by endostatin on C6 growth, complete tumor inhibition or dormancy was not observed in either the athymic or immunocompetent tumor models. These findings demonstrate that the endogenous expression of endostatin by C6 glioma cells results in a reduced tumor growth rate in vivo that is associated with an inhibition of tumor angiogenesis. Our data suggest that endostatin should be developed as an adjuvant gene therapy for the effective treatment of gliomas.
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PMID:Antiangiogenic activity of endostatin inhibits C6 glioma growth. 1185 65

The use of tumor angiogenesis as a therapeutic target is based on extensive literature showing the dependence of tumors on the process of angiogenesis for growth, invasion, and metastasis. Seminal work performed by Folkman three decades ago determined that tumors beyond the size of approximately 2 mm require angiogenesis for subsequent growth and development. This basic hypothesis stimulated research in the field of angiogenesis and has resulted in the identification of factors that both enhance and inhibit this "angiogenic switch." The intent of this article is to present data on several angiogenesis inhibitors that are currently undergoing clinical evaluation in cancer patients. These agents may be particularly useful in the treatment of lung cancer, both as adjunctive therapy in early-stage or locally advanced disease, as well as in combination strategies with platinum-based therapy in metastatic disease. Although angiogenesis inhibitors have been in clinical trials for the past decade, there has been a shift in recent years towards the development of more mechanism-based and receptor-targeted agents. Interestingly, no antiangiogenic agent has been approved as such for use in cancer, perhaps because of the challenges involved in the clinical development of these novel agents. These include the potential requirement for long-term administration, difficulties in deriving biologically efficacious doses in early clinical trials, and the inability to use tumor regression as a primary endpoint in phase II trials.
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PMID:Angiogenesis inhibitors in clinical development for lung cancer. 1189 16

Endostatin decreased vascular endothelial growth factor (VEGF)-induced formation of endothelial tubes and microvessels sprouting from aortic rings and blocked their network. After cessation of treatment, the survival time of endostatin plus VEGF-treated tubes was approximately doubled in comparison to VEGF alone. Endostatin antibody blocked VEGF-induced endothelial tube formation and disrupted existing tubes. Endostatin immunostaining was localized between endothelium and basement membrane and in inter-endothelial junctions of new, but not of quiescent, blood vessels. In tumors grown in SCID mice, endostatin immunostaining was stronger accompanying blood vessel maturation and was significantly prominent in vessels of tumor marginal zone where angiogenesis is highly active. These data indicate a new antiangiogenic action of endostatin stabilizing and maturating endothelial tubes of newly formed blood vessels. Thus, strategies accelerating vascular stabilization and maturation could be promising in tumor therapy.
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PMID:Endostatin inhibits angiogenesis by stabilization of newly formed endothelial tubes. 1191 Oct 17

Endostatin, an endogenous angiogenesis inhibitor, attenuates endothelial cell migration through an unknown mechanism. We show that endostatin induced tyrosine phosphorylation of focal adhesion kinase and paxillin, and promoted formation of focal adhesions and actin stress fibers, similar to fibroblast growth factor-2 (FGF-2). In cells cotreated with endostatin and FGF-2, focal adhesions and actin stress fibers were decreased, indicating that endostatin disturbs cell-matrix adhesion. Reduced tyrosine phosphorylation and cytoplasmic relocalization of beta-catenin in cells treated with FGF-2 and endostatin indicates that loosening of cell-cell adhesion is also disturbed by endostatin. These data provide a molecular basis both for the lack of effect of endostatin on the normal, quiescent vasculature, and its antagonistic effects on stimulated tumor vessels.
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PMID:Endostatin regulates endothelial cell adhesion and cytoskeletal organization. 1192 7

Endostatin, a 20-kDa carboxy-terminal fragment of collagen XVIII, is the leading member of a class of physiologic inhibitors of angiogenesis with potent antitumor activity. Repeated subcutaneous administration of recombinant endostatin in mice led to permanent regression of established tumors to a microscopic dormant state and prompted the initiation of human clinical trials. However, a discrepancy remained unresolved: sustained tumor regression has only been observed with a non-soluble, precipitated form of recombinant endostatin produced in bacteria. To shed light on this question and establish a model of systemic anti-angiogenic gene therapy of cancer that may surmount obstacles in protein production and delivery, we transduced murine hematopoietic stem cells with a retrovirus encoding a secretable form of endostatin. Despite continuous, high-level secretion of endostatin in the vasculature of all transplanted mice, we detected neither inhibition of in vivo neoangiogenesis nor antitumor activity. Resolution of this paradox may come from human trials of endostatin now underway.
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PMID:Continuous intravascular secretion of endostatin in mice from transduced hematopoietic stem cells. 1194 58

A novel naturally occurring antiangiogenic agent isolated from cartilage, referred to as Neovastat (AE-941), was examined for its efficacy against tumor neovascularization and progression. Exposure to Neovastat results in ex ovo antiangiogenic properties in the chorioallantoid membrane of chicken embryo (71% decrease in the angiogenic index as compared to the basic fibroblast growth factor (bFGF) treated control embryos, P < 0.0001). Oral administration of Neovastat inhibits bFGF-induced angiogenesis in the Matrigel mouse model (87.5% decrease in hemoglobin as compared to the bFGF-treated control implants, P < 0.0001). Neovastat also induces a dose response decrease of lung metastases in the Lewis lung carcinoma model (oral administration; 69.1% of inhibition obtained at the maximal dose of 0.5 ml/day, P < 0.0001). Combined with a sub-optimal dose of cisplatinum (2 mg/kg, i.p.), Neovastat (0.5 ml/day) improved the therapeutic index by increasing the antimetastatic efficacy and by exerting a protective activity against cisplatinum-induced body weight loss and myelosuppression. In summary, our experimental data provide evidence of antiangiogenic and antimetastatic properties of Neovastat, following oral administration.
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PMID:Antiangiogenic and antimetastatic properties of Neovastat (AE-941), an orally active extract derived from cartilage tissue. 1196 78

Since angiogenesis is essential for the growth of any solid tumor, emerging efforts are being made to develop antiangiogenic therapy. To date, however, no antiangiogenic agent has become widely available for the clinical setting. Angiotensin I-converting enzyme (ACE) inhibitors are commonly used as antihypertensive agents and it has recently been suggested that they decrease the risk of cancer. Studies have found that an ACE inhibitor, perindopril, is a potent inhibitor of experimental tumor development and angiogenesis at a clinically comparable dose. The potent angiogenic factor, vascular endothelial growth factor (VEGF), is significantly suppressed by perindopril and also inhibits VEGF-induced tumor growth. In vitro studies showed that perindopril is not cytotoxic to either tumor cells or endothelial cells. Since perindopril is already in widespread clinical use without serious side effects, it may represent a potential new strategy for anticancer therapy.
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PMID:Perindopril: possible use in cancer therapy. 1198 65

We previously reported that endostatin inhibits endothelial and tumor cellular invasion by blocking activation and catalytic activity of matrix metalloproteinase (MMP)-2. Here we have examined the domain of proMMP-2 responsible for the binding of endostatin using surface plasmon resonance. ProMMP-2 and proMMP-2deltaHP lacking the hinge and hemopexin-like (HP) domains bound little to the immobilized endostatin. The active MMP-2 and MMP-2deltaHP, but not the HP domain of MMP-2, bound to endostatin at similar levels. In addition, preincubation of MMP-2 and MMP-2deltaHP with the MMP inhibitor actinonin, which binds to the active site of MMP-2, abolished their bindings to endostatin. These results indicate that endostatin binds to neither the latent proMMP-2 nor the HP domain but to the catalytic domain of MMP-2.
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PMID:Endostatin binds to the catalytic domain of matrix metalloproteinase-2. 1202 34

Endostatin, a fragment of collagen XVIII, is a potent anti-angiogenic protein, but the molecular mechanism of its action is not yet clear. We examined the effects of endostatin on the biological and biochemical activities of vascular endothelial growth factor (VEGF). Endostatin blocked VEGF-induced tyrosine phosphorylation of KDR/Flk-1 and activation of ERK, p38 MAPK, and p125(FAK) in human umbilical vein endothelial cells. Endostatin also inhibited the binding of VEGF(165) to both endothelial cells and purified extracellular domain of KDR/Flk-1. Moreover, the binding of VEGF(121) to KDR/Flk-1 and VEGF(121)-stimulated ERK activation were blocked by endostatin. The direct interaction between endostatin and KDR/Flk-1 was confirmed by affinity chromatography. However, endostatin did not bind to VEGF. Our findings suggest that a direct interaction of endostatin with KDR/Flk-1 may be involved in the inhibitory function of endostatin toward VEGF actions and responsible for its potent anti-angiogenic and anti-tumor activities in vivo.
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PMID:Endostatin blocks vascular endothelial growth factor-mediated signaling via direct interaction with KDR/Flk-1. 1202 87


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