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 angiogenesis is stimulated by a pro-angiogenic shift in both inducers and inhibitors of endothelial growth. To study this shift, we measured serum and plasma levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), endostatin, and thrombospondin 1 (TSP1) in 21 advanced non-small cell lung cancer (NSCLC) patients and 46 healthy control subjects. In addition, we assessed the relevance of these levels to disease outcome. Cytokine levels were prospectively measured in plasma and serum by enzyme-linked immunosorbent assay at three times: before chemotherapy and at 1 and 12 weeks following initiation of chemotherapy. In NSCLC patients, serum VEGF levels (sVEGF) were elevated (p<0.001), whereas serum and plasma TSP1 levels were lower (p=0.012 and p=0.004, respectively) than in healthy control subjects. Pretreatment plasma endostatin and serum bFGF levels were higher in NSCLC patients than in healthy controls (p=0.05 and 0.01, respectively). Change in sVEGF at week 12 after initiation of chemotherapy correlated with response to therapy (p=0.002). Patients with pretreatment sVEGF levels <500 pg/mL had a median survival of 11 months, but those with sVEGF >500 pg/mL had only a 6 months' median survival (p < 0.03). In NSCLC patients, VEGF levels are increased, whereas TSP1 levels are decreased, which may trigger and sustain tumor angiogenesis. High levels of serum VEGF at the time of presentation with NSCLC may predict worse survival.
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PMID:Circulating angiogenic cytokines in patients with advanced non-small cell lung cancer: correlation with treatment response and survival. 1594 4

The growth and survival of a malignant tumor are dependent on the formation and maintenance of its own microvasculature, a process termed angiogenesis. Inhibition of this phenomenon is an emerging strategy in cancer therapy. The extracellular matrix surrounding the vascular endothelial cells contains cryptic protein domains, which are exposed by changes in the proteolytic homeostasis of the tumor microenvironment. These fragments transmit local signals, which regulate vascular endothelial cell proliferation and migration. Endostatin, the proteolytic fragment of collagen type XVIII, is a potent inhibitor of tumor angiogenesis in various mouse models and is currently in clinical trials for therapeutic use in human cancer. Multiple cell surface receptors have been described for endostatin, but the signals transmitted by these receptors resulting in the inhibition of angiogenesis have so far been poorly characterized. Studies on the effects of endostatin on cultured endothelial cells suggest that the antimigratory and antiproliferative properties of this molecule are the major mechanisms underlying its antiangiogenic potential. These effects may be a consequence of endostatin modulation of endothelial cell-matrix interactions and pericellular proteolysis.
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PMID:Endostatin signaling and regulation of endothelial cell-matrix interactions. 1609 2

Intravenous gene delivery using liposome-DNA complexes (LDC) has previously been shown to elicit antitumor activity, but only in rodent tumor models. Therefore, we conducted a study to determine in a large animal spontaneous tumor model whether intravenous infusions of LDC could target gene expression to cutaneous tumor tissues and whether repeated treatments had an effect on tumor growth or angiogenesis. A total of 13 dogs with cutaneous soft tissue sarcomas were enrolled in the study and were randomized to receive a series of 6 weekly infusions of LDC containing either canine endostatin DNA or DNA encoding an irrelevant gene (luciferase). Serial tumor biopsies were obtained to assess transgene expression, tumor microvessel density (MVD), and intratumoral leukocyte inflammatory responses. We found that intravenous infusion of LDC did not result in detectable gene expression in cutaneous tumor tissues. However, two of 13 treated dogs had objective tumor responses and eight dogs had stable disease during the treatment period. In addition, a significant decrease in tumor MVD was noted in six of 12 treated dogs at the completion of six treatments. These results suggest that intravenous infusions of LDC may elicit nonspecific antitumor activity and inhibit tumor angiogenesis.
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PMID:Liposome-DNA complexes infused intravenously inhibit tumor angiogenesis and elicit antitumor activity in dogs with soft tissue sarcoma. 1613 18

The growth of tumor is angiogenesis-dependent and it often contains hypoxia and necrotic areas. Salmonella VNP20009 could target and replicate in hypoxia and necrotic areas within tumor and induce antitumor effect. Angiogenesis inhibitor endostatin could reduce tumor angiogenesis and inhibit its growth. However, in the phase I trials of VNP20009 and endostatin at the maximum-tolerated dose, no antitumor effects for bacteria therapy and minor therapeutic effects for endostatin treatment were seen. The ineffectiveness of these agents in clinical trials suggests that the combination of these agents with synergic modalities might be necessary. Here we described antitumor effects mediated by the combination of VNP20009 with recombinant human endostatin in B16F10 murine melanoma model with the aim to exploit tumor-targeting of bacteria and anti-angiogenesis strategy to enhance therapeutic efficacy. Combination therapy of these agents significantly enhanced antitumor effects by inducing greater tumor growth inhibition, more severe tumor tissue necrosis as well as less blood vessel density than those induced by either of treatments. The findings suggest that the combination of tumor-targeting bacteria with angiogenesis inhibitor might be of value for the treatment of solid tumors.
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PMID:Enhanced therapeutic effect by combination of tumor-targeting Salmonella and endostatin in murine melanoma model. 1612 82

Endostatin is an endogenous inhibitor of tumor angiogenesis and tumor growth. It has two pairs of disulfide bonds in a unique nested pattern, which play a key role in its native conformation, stability, and activity. Here, we constructed a disulfide-deficient variant of endostatin, endo-all-Ala, to examine the effects of the two disulfide bonds on fibrillogenesis of endostatin under nondenaturing conditions. Based on thioflavin T fluorescence, atomic force microscopy, far-UV circular dichroism, and Fourier transform infrared spectroscopy, we found that endo-all-Ala, which has a higher alpha-helical content compared with wild type, is prone to forming fibrils in a pH-dependent manner. Subsequently, more hydrophobic patches with a lower stability of endo-all-Ala were observed when compared with wild type, which possibly contributes to the propensity of amyloid formation of endo-all-Ala. To our surprise, the significant increase of the alpha-helical content in endostatin induced by trifluoroethanol can also facilitate fibril formation. In addition, the cytotoxicity of fibrillar aggregates of endo-all-Ala, which were generated at different stages of the fibril formation process, was evaluated by cell viability assay. The results indicate that the cytotoxicity is not due to the fibrils but rather due to the granular aggregates of endo-all-Ala. Moreover, endostatin was interestingly found to be reduced by glutathione at physiological concentrations. Our present work not only elucidates the correlation between the existence of disulfide bonds and the fibril formation of endostatin but also may provide some insights into the structural and functional basis of endostatin in Alzheimer disease brains.
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PMID:Deficiency of disulfide bonds facilitating fibrillogenesis of endostatin. 1626 8

At present, a variety of agents targeting tumor angiogenesis are under clinical investigation as new therapies for patients with cancer. Overexpression of the alpha(v)beta(3) integrin on tumor vasculature has been associated with an aggressive phenotype of several solid tumor types. Murine models have shown that antibodies targeting the alpha(v)beta(3) integrin can affect tumor vasculature and block tumor formation and metastasis. These findings suggest that antibodies directed at alpha(v)beta(3) could be investigated in the treatment of human malignancies. The current phase I dose escalation study evaluated the safety of MEDI-522, a monoclonal antibody specific for the alpha(v)beta(3) integrin, in patients with advanced malignancies. Twenty-five patients with a variety of metastatic solid tumors were treated with MEDI-522 on a weekly basis with doses ranging from 2 to 10 mg/kg/wk. Adverse events were assessed weekly; pharmacokinetic studies were done; and radiographic staging was done every 8 weeks. In addition, dynamic computed tomography imaging was done at baseline and at 8 weeks in patients with suitable target lesions amenable to analysis, to potentially identify the effect of MEDI-522 on tumor perfusion. Treatment was well tolerated, and a maximum tolerated dose was not identified by traditional dose-limiting toxicities. The major adverse events observed were grade 1 and 2 infusion-related reactions (fever, rigors, flushing, injection site reactions, and tachycardia), low-grade constitutional and gastrointestinal symptoms (fatigue, myalgias, and nausea), and asymptomatic hypophosphatemia. Dynamic computed tomography imaging suggested a possible effect on tumor perfusion with an increase in contrast mean transit time from baseline to the 8-week evaluation with increasing doses of MEDI-522. No complete or partial responses were observed. Three patients with metastatic renal cell cancer experienced prolonged stable disease (34 weeks, >1 and >2 years) on treatment. With this weekly schedule of administration, and in the doses studied, MEDI-522 seems to be without significant toxicity, may have effects on tumor perfusion, and may have clinical activity in renal cell cancer. These findings suggest the MEDI-522 could be further investigated as an antiangiogenic agent for the treatment of cancer.
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PMID:Phase I trial of a monoclonal antibody specific for alphavbeta3 integrin (MEDI-522) in patients with advanced malignancies, including an assessment of effect on tumor perfusion. 1627 8

We have previously observed that the synthetic peptide corresponding to amino acids 31-45 (PCK3145) of PSP94 can reduce prostate tumor growth in vivo. Moreover, a recently concluded phase IIa clinical trial with patients with hormone refractory prostate cancer indicated that PCK3145 down-regulates the levels of plasma matrix metalloproteinase (MMP)-9, a MMP involved in metastasis and tumor angiogenesis. The purpose of our study was to investigate the molecular mechanisms of action of PCK3145 and whether this peptide could antagonize tumor neovascularization. We show that, in a syngeneic in vivo model of rat prostate cancer, the expression of endothelial cell (EC) specific CD31, a marker of tumor vessel density, was decreased by 43% in PCK3145-treated animals. In vitro, PCK3145 specifically antagonized in a dose-dependent manner the VEGF-induced ERK phosphorylation as well as the phosphorylation of the VEGFR-2 in cultured EC (HUVEC). These anti-VEGF effects were partly reproduced by pharmacological inhibitors such as PD98059 and PTK787, suggesting that PCK3145 inhibits the tyrosine kinase activity associated to VEGFR-2, which in turn prevents intracellular signalling through the MAPK cascade. Moreover, PCK3145 was also found to inhibit the PDGF-induced phosphorylation of PDGFR in smooth muscle cells. Finally, PCK3145 inhibited in vitro EC tubulogenesis and VEGF-induced MMP-2 secretion suggesting its potential implication as an antiangiogenic agent. Our study demonstrates that PCK3145 interferes with the tyrosine kinase activity associated with VEGF signalling axis in EC. The antiangiogenic properties of this peptide could be highly beneficial and exploited in novel antiangiogenic therapies, for patients with various cancers.
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PMID:A prostate secretory protein94-derived synthetic peptide PCK3145 inhibits VEGF signalling in endothelial cells: implication in tumor angiogenesis. 1633 3

Treatment options for advanced colorectal have improved substantially in recent years as a number of agents have been developed that have different targets and mechanisms of action. Significant improvements in outcomes have been observed by combining multiple chemotherapeutic agents instead of the single-agent approach. Some debate still remains regarding which combination is most effective and in what order regimens should be given. In addition to cytotoxic chemotherapy drugs, targeted biologic agents have been developed to inhibit tumor angiogenesis, which may hamper the viability of the tumor. There may also be a synergistic effect between antiangiogenic agents and chemotherapy. Regulation of tumor angiogenesis may actually improve blood flow throughout the tumor, which could enhance delivery of chemotherapy through the circulation. One antiangiogenic agent currently approved for the treatment of advanced colorectal cancer is bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor, a ligand known to be important for angiogenesis. The other currently approved biologic agent, cetuximab, targets the epidermal growth factor receptor. The combination of bevacizumab plus cetuximab has a biologic rationale. Randomized trials incorporating combination chemotherapy regimens plus both bevacizumab and cetuximab are currently underway, as are preliminary studies withnovel angiogenesis inhibitors.
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PMID:Angiogenesis inhibition in the treatment of colorectal cancer Part 3 of a 3-part series: targeting VEGF--current and future research directions. 1655 33

Vascular endothelial cells receive proangiogenic or antiangiogenic signals from components of extracellular matrix (ECM) depending upon the situation and many molecular signals can have opposite effects in different vascular beds. Tissue inhibitor of metalloproteinase 1 is antiangiogenic in several tissues, but promotes retinal neovascularization. When cleaved from native collagens, several of the non-collagenous domains (NC1) of basement membrane collagens have antiangiogenic effects in some tissues, but this is context dependent for the NC1 of the alpha 1 chain of collagen IV. It is critical to examine effects in several well-defined model systems before assuming that an ECM component is universally antiangiogenic. In this study, we examined the effects of a recombinant fragment of NC1 of the alpha 2 chain of type IV collagen (alpha2(IV)NC1) in a well-characterized model of ocular neovascularization. Intravitreous or periocular injections of alpha2(IV)NC1 caused selective apoptosis of endothelial cells participating in neovascularization resulting in suppression of neovascularization when the peptide was given prior to onset of new vessel sprouting. Importantly, when the peptide was given after neovascularization had already developed, it caused the new vessels to regress. This suggests that alpha2(IV)NC1, which has previously been shown to suppress tumor angiogenesis in xenograft models, is also a strong antiangiogenic agent in the choroid and is a therapeutic candidate for treatment of neovascular age-related macular degeneration.
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PMID:Recombinant non-collagenous domain of alpha2(IV) collagen causes involution of choroidal neovascularization by inducing apoptosis. 1655 20

Craniopharyngiomas are benign tumors of the sellar region generally associated with endocrine abnormality and often locally aggressive. Several studies have demonstrated that angiogenesis or neovascularization plays an important role in tumoral growth. The microvascular density (MVD) of craniopharyngiomas was determined in tumor tissue samples from a reference neurosurgery center located in southern Brazil using immunohistochemical methods for two endothelial markers, CD34 and CD105 (endoglin). In addition, tissue expression was determined for an angiogenesis stimulatory factor and for one of its inhibitors, the vascular endothelial growth factor (VEGF) and endostatin, respectively. Endothelial cell immunoreactivity for CD34 and CD105 was observed scattered within the stroma. MVD determined using CD105 antigen was significantly lower than the results obtained by using CD34 antigen. There was no association between the two endothelial markers and tumor extension. The epithelial component showed different degrees of immunoreactivity for VEGF and endostatin in all samples analyzed. We were not able to establish a relationship between angiogenesis in craniopharyngiomas and tumor extension with the endothelial markers used in this study. The investigated vascularization stimulatory and inhibitory factors showed no relation with MVD. We believe that CD105 antigen can be a more specific endothelial marker for tumor angiogenesis than CD34 antigen.
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PMID:Angiogenesis in craniopharyngiomas: Microvascular density and tissue expression of the vascular endothelial growth factor (VEGF) and endostatin. 1662 22


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