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)

Tumor cells secrete diffusible substances collectively called tumor angiogenic factors (TAFs), most notably vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), which in turn stimulate endothelial cell migration and thus angiogenesis, or new blood vessel formation. Anti-angiogenic drugs for cancer treatment are receiving much attention, with endostatin identified as one of the potent inhibitors. Although the mechanisms of action of endostatin are yet to be fully elucidated, there is evidence that bFGF and endostatin may bind competitively to heparan sulfate proteoglycan receptors on endothelial cells, or endostatin may otherwise downregulate bFGF or VEGF and its receptors, putatively inhibiting cell proliferation. To test these and other hypotheses of inhibitory action that can be similarly formulated, for other TAF inhibitors as well as endostatin, we have developed a mathematical model of extratumoral angiogenesis in cancer in response to specific anti-angiogenic drug treatment. It is built on previous work, a modification and augmentation of published models, and is expressed as four nonlinear partial differential equations, with specific terms for endothelial cell proliferation, degradation, and endostatin-TAF inhibition, and a stochastic, discretized version of this model to represent vessel growth. Our extended model reproduces the simulated kinetics of angiogenesis in a mouse tumor model reported earlier. We assessed the anti-angiogenic kinetic behavior of our extended model by simulating dynamic responses to exogenous endostatin treatment in the same mouse model, using four dosage regimens, two of these reported for in vivo pre-clinical or clinical studies, and two 10 times greater: daily single bolus injections of 20 mg/kg per day and 200 mg/kg per day, and constant infusions of 20 mg/kg per day and 200 mg/kg per day, each for 20 simulated days. We also explored the effects of drug clearance, over an eightfold range of clearance rates that include scaled clearances for endostatin, a sister-drug angiostatin, or similar drugs with clearances in this range. Predictively, our simulation results suggest ineffectiveness of the bolus injection protocols, consistent with in vivo data with angiostatin treatment, whereas simulated constant infusion of endostatin in the mouse model effectively suppresses angiogenesis after only 3 days of treatment, at the lowest dose, over a wide range of drug clearance rates.
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PMID:Simulation of tumor-induced angiogenesis and its response to anti-angiogenic drug treatment: mode of drug delivery and clearance rate dependencies. 1458 44

It has now been almost 30 years since Dr J. Folkman first proposed that inhibition of angiogenesis could play a key role in treating cancer; however, it is only recently that anti-angiogenesis agents have entered the clinical setting. The search for novel therapies is particularly important in lung cancer, where the majority of patients succumb to their disease despite aggressive treatments. Several classes of agents now exist that target the different steps involved in angiogenesis. These include drugs inhibiting matrix breakdown, the matrix metalloproteinase inhibitors (MMPIs), such as marimastat, prinomastat, BMS275291, BAY12-9566, and neovastat drugs that block endothelial cell signaling via vascular endothelial growth factor (VEGF) and its receptor (VEGFR) including rhuMAb VEGF, SU5416, SU6668, ZD6474, CP-547,632 and ZD4190. Drugs that are similar to endogenous inhibitors of angiogenesis including endostatin, angiostatin and interferons. There has also been renewed interest in thalidomide. Drugs such as squalamine, celecoxib, ZD6126, TNP-470 and those targeting the integrins are also being evaluated in lung cancer. Despite early enthusiasm for many of these agents, Phase III trials have not yet demonstrated significant increases in overall survival and toxicity remains an issue. It is hoped that as our understanding of the complex process of angiogenesis increases, so will our ability to design more effective targeted therapies.
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PMID:Targeting angiogenesis: a review of angiogenesis inhibitors in the treatment of lung cancer. 1461 19

Circulating endothelial cells (CECs) are present in peripheral blood and have been shown to contribute to normal and pathological neovascularization. Antiangiogenic molecules can inhibit neovascularization in tumors and other sites, but their effect on CECs has not yet been determined. We hypothesize that angiogenic factors will increase the number of CECs, and conversely, antiangiogenic treatment will reduce these numbers. Mice treated with high levels of vascular endothelial growth factor (VEGF) showed increased numbers of Flk-1-positive cells in peripheral blood and endothelial cell colonies compared with vehicle-treated controls. These changes were accompanied by increased bone marrow neovascularization. In contrast, mice that received VEGF and endostatin had significantly lower numbers of CECs and reduced bone marrow vascularization. Endostatin-induced apoptosis was probably responsible for the decreased number of CECs. Systemic delivery of a VEGF antagonist, soluble Flt-1, also inhibited the VEGF-induced increase in CECs. These results were further confirmed in a Tie2/LacZ mouse model, in which endostatin reduced the number of beta-galactosidase-expressing peripheral blood mononuclear cells. We propose that endothelial progenitor cells are a novel target for endostatin and suggest that the relative numbers of CECs can serve as a surrogate marker for the biological activity of antiangiogenic treatment.
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PMID:Endostatin inhibits the vascular endothelial growth factor-induced mobilization of endothelial progenitor cells. 1467 95

The multifaceted nature of the angiogenic process in malignant neoplasms suggests that protocols that combine antiangiogenic agents may be more effective than single-agent therapies. However it is unclear which combination of agents would be most efficacious and will have the highest degree of synergistic activity while maintaining low overall toxicity. Here we investigate the concept of combining a "direct" angiogenesis inhibitor (endostatin) with an "indirect" antiangiogenic compound [SU5416, a vascular endothelial growth factor receptor 2 (VEGFR2) receptor tyrosine kinase (RTK) inhibitor]. These angiogenic agents were more effective in combination than when used alone in vitro (endothelial cell proliferation, survival, migration/invasion, and tube formation tests) and in vivo. The combination of SU5416 and low-dose endostatin further reduced tumor growth versus monotherapy in human prostate (PC3), lung (A459), and glioma (U87) xenograft models, and reduced functional microvessel density, tumor microcirculation, and blood perfusion as detected by intravital microscopy and contrast-enhanced Doppler ultrasound. One plausible explanation for the efficacious combination could be that, whereas SU5416 specifically inhibits vascular endothelial growth factor signaling, low-dose endostatin is able to inhibit a broader spectrum of diverse angiogenic pathways directly in the endothelium. The direct antiangiogenic agent might be able to suppress alternative angiogenic pathways up-regulated by the tumor in response to the indirect, specific pathway inhibition. For future clinical evaluation of the concept, a variety of agents with similar mechanistic properties could be tested.
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PMID:Combined therapy with direct and indirect angiogenesis inhibition results in enhanced antiangiogenic and antitumor effects. 1469 6

Patients with advanced non-small-cell lung cancer (NSCLC) have a poor prognosis and high mortality. The therapeutic improvement caused by the new generation of cytotoxic agents seems to have reached a plateau. The main categories of targeted therapeutics applicable for NSCLC include receptor-targeted therapy, signal transduction or cell-cycle inhibition, angiogenesis inhibitors, gene therapy, and vaccines. Several major classes of agents directed at specific cellular mechanisms exist for the treatment of NSCLC. The anti-epidermal growth factor receptor (EGFR) group contains trastuzumab and IMC-C225, monoclonal antibodies against EGFRs that are overexpressed in many cancers. OSI-774 and ZD1839 are inhibitors of EGFR tyrosine kinase, a key enzyme of the signaling pathway. Farnesyl transferase inhibitors, such as SCH66336, and protein kinase C inhibitors, such as ISIS 3521, have also shown antitumor activity. Antiangiogenesis agents that have shown promise include TNP-470, recombinant endostatin, and angiostatin. Antibodies to vascular endothelial growth factor (VEGF) also seem to control tumor progression and may prolong survival. LY317615, an inhibitor of protein kinase Cb, augmented the tumor growth delay produced by cytotoxic drugs. All of these agents are in different phases of clinical testing and have shown encouraging activity as single agents or in combination with chemotherapy drugs. These new agents are more target specific, less toxic, easier to administer, and may lead to enhanced safety and survival for patients with advanced NSCLC.
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PMID:Targeted therapy using novel agents in the treatment of non-small-cell lung cancer. 1472 Mar 53

Serum vascular endothelial growth factor (VEGF) and endostatin levels were detected in 59 patients with breast cancer before surgery and at 3 weeks after surgery. Pre-operatively, their levels were significantly elevated and correlated with each other. Post-operatively, VEGF level decreased significantly and endostatin remained at a high level. Patients with both normalized VEGF and elevated endostatin following surgery had a lower risk of relapse than patients whose VEGF failed to normalize. Univariate and multivariate analyses showed a correlation between elevated VEGF level and short free-relapse survival. These findings suggest a new angiogenesis balance is formed in the patients after surgery and such a resultant balance may be beneficial for the prognosis of breast cancer, which deserves more extensive study.
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PMID:Correlation between serum vascular endothelial growth factor and endostatin levels in patients with breast cancer. 1474 38

Concomitant tumour resistance (CTR) is a unique phenomenon in which animals harbouring large primary tumours are resistant to the growth of smaller metastatic tumours by systemic angiogenic suppression. To examine this clinically, in ten patients with osteosarcoma, we investigated the effects of removal of the primary tumour on the development of pulmonary metastases, the systemic angiogenesis-inducing ability and the serum levels of several angiogenesis modulators. We found that removal of the primary tumour significantly elevated systemic angiogenesis-inducing ability in five patients who had post-operative recurrence of the tumour. Post-operative elevation of the angiogenesis-induced ability was suppressed by the addition of an angiogenic inhibitor, endostatin. Also, primary removal of the tumour decreased the serum levels of vascular endothelial growth factor and endostatin. These findings suggest, for the first time, the presence of CTR in patients with osteosarcoma for whom post-operative antiangiogenic therapy may be used to prevent the post-operative progression of micrometastases.
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PMID:Concomitant tumour resistance in patients with osteosarcoma. A clue to a new therapeutic strategy. 1476 82

Angiogenesis is controlled by anti-angiogenic factors as well as by angiogenic factors, such as VEGF (vascular endothelial growth factor) and HGF (hepatocyte growth factor). Endostatin, a potent endogenous angiogenesis inhibitor, is known to inhibit endothelial proliferation and suppress tumour growth. However, to date, little is known about the pathophysiology of endostatin in ischaemia/reperfusion. To investigate the mechanisms of angiogenesis induced by myocardial ischaemia/reperfusion in more detail, we studied the circulating levels of endostatin, VEGF and HGF in 17 patients with acute myocardial infarction, who underwent early reperfusion therapy. In all patients, serum endostatin, VEGF and HGF levels before reperfusion were increased significantly compared with those in 17 control subjects (endostatin, 49.2+/-11.7 ng/ml, but not detectable in controls; VEGF, 685.6+/-150.3 pg/ml compared with 173.7+/-33.6 pg/ml; HGF, 3638+/-1285 pg/ml compared with 59+/-13 pg/ml; values are means+/-S.E.M.). After reperfusion, the serum endostatin and VEGF levels decreased significantly, but still remained higher than those in control subjects (endostatin, 19.6+/-7.0 ng/ml; VEGF, 284.2+/-90.2 pg/ml). In contrast, serum HGF levels increased significantly (15 146+/-2230 pg/ml) after reperfusion. These data indicated that serum levels of endostatin changed in parallel with those of VEGF in response to myocardial ischaemia/reperfusion, and the marked increase in serum HGF levels after reperfusion seemed to be, at least in part, due to heparin administration. Our data offer a possible anti-endostatin therapy in patients with acute myocardial infarction to facilitate collateral vessel formation.
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PMID:Serum levels of endostatin, vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in patients with acute myocardial infarction undergoing early reperfusion therapy. 1523 Jun 92

Multiplexed photoaptamer-based arrays that allow for the simultaneous measurement of multiple proteins of interest in serum samples are described. Since photoaptamers covalently bind to their target analytes before fluorescent signal detection, the arrays can be vigorously washed to remove background proteins, providing the potential for superior signal-to-noise ratios and lower limits of quantification in biological matrices. Data are presented here for a 17-plex photoaptamer array exhibiting limits of detection below 10 fM for several analytes including interleukin-16, vascular endothelial growth factor, and endostatin and able to measure proteins in 10% serum samples. The assays are simple, scalable, and reproducible. Affinity of the capture reagent is shown to be directly correlated to the limit of detection for the analyte on the array.
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PMID:Photoaptamer arrays applied to multiplexed proteomic analysis. 1499 84

It is known that angiogenesis is of pivotal importance for the development of endometriosis. However, in the treatment of endometriosis patients, prevention of endometriosis lesion development only will not be sufficient as a therapy. Treatment options, aimed at interfering with established lesions, have to be developed. In this study we evaluated whether inhibition of angiogenesis by angiostatic therapy is also effective in antagonizing the sustentation of endometriosis. We evaluated the effect of the angiostatic compounds antihuman vascular endothelial growth factor, TNP-470, endostatin, and anginex on the growth of established endometriosis lesions in the nude mouse model. We show that human endometrium in the proliferative endometrium is highly angiogenic and that vascular endothelial growth factor-A is the most important angiogenesis promotory factor. The angiostatic compounds significantly decreased microvessel densities and the number of established endometriosis lesions. In the remaining lesions, the number of pericyte-protected vessels is not different in control and treated mice; however, the number of unprotected vessels was significantly reduced in the groups treated with the angiostatic agents. Our data demonstrate that inhibitors of angiogenesis effectively interfere with the maintenance and growth of endometriosis by inhibiting angiogenesis. This suggests that the use of angiostatic agents may be promising as a therapy for endometriosis.
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PMID:Antiangiogenesis therapy for endometriosis. 1500 92


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