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)

Linomide is a p.o. active antiangiogenic agent that has been demonstrated to be effective in suppressing the in vivo growth of rat and human prostatic cancer xenografts. The present studies were conducted to determine whether the angiogenic molecules, vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) and basic fibroblast growth factor (bFGF) are expressed in vitro by DU-145, PC-3, TSU-PR1, and LnCaP human prostate cancer cell lines and whether Linomide inhibits the secretion of these angiogenic molecules. Additionally, two different androgen-responsive human prostatic cancer xenograft models (i.e., PC-82 and A-2) were used to determine whether androgen ablation-induced reduction in tumor growth is associated with a reduction in tumor VEGF and/or bFGF levels. These studies demonstrated that both VEGF and bFGF proteins are expressed to different degrees in the human prostatic cancer cell lines. The secretion of VEGF but not bFGF is up-regulated by hypoxia. Linomide is unable to inhibit either basal or hypoxia-induced secretion of VEGF. Linomide also has no effect on secreted bFGF levels. Castration inhibited tumor VEGF but had no effect on bFGF levels in both the androgen-responsive PC-82 and A-2 human prostatic cancers when grown in severe combined immunodeficient mice. When given in combination, castration potentiated the inhibition of tumor growth induced by Linomide alone. This potentiation is not due to a further inhibition in tumor VEGF levels induced by castration. Although both castration and Linomide inhibit angiogenesis, the former accomplishes it by inhibiting VEGF secretion, whereas the latter has multiple effects at several steps in the angiogenic process other than VEGF secretion. Based on their different but complementary mechanisms of action, simultaneous combination of androgen ablation with Linomide enhances the anti-prostatic cancer efficacy compared to either monotherapies alone and warrants testing in humans.
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PMID:Potentiation of the antiangiogenic ability of linomide by androgen ablation involves down-regulation of vascular endothelial growth factor in human androgen-responsive prostatic cancers. 906 70

We conducted a Phase II clinical trial of the antiproliferative, antimetastatic, and antiangiogenic agent carboxyamido-triazole (CAI), using pharmacokinetic assessment to guide drug dosing. Fifteen patients who had stage D2 androgen-independent prostate cancer with soft tissue metastases were enrolled. Because CAI previously had been shown to decrease prostate-specific antigen secretion in vitro, this marker was not used to assess disease status. The dose of CAI used in this study was calculated so that plasma steady-state maximum concentrations between 2.0 and 5.0 microg/ml would be maintained. Following the initial dosage adjustment, 93% (14 of 15) of patients were within the predicted range. Fourteen of 15 patients were evaluable for response. All of the 14 evaluable patients demonstrated progressive disease at approximately 2 months. Twelve patients progressed by computed tomography and or bone scan at 2 months, whereas two patients demonstrated clinical progression at 1.5 and 2 months. One patient was removed from study at 6 weeks due to grade II peripheral neuropathy lasting >1 month. Although no clinical responses were noted, a 27.7% decrease in serum vascular endothelial growth factor concentration was observed. CAI does not possess clinical activity in patients with androgen-independent prostate cancer and soft tissue metastases. Pharmacokinetically guided dosing, although found to be feasible using a Bayesian approach, was not found to be of practical benefit. Although plasma CAI concentrations were maintained within the designated range, grade III toxicity requiring drug discontinuation was still observed.
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PMID:A pharmacokinetically guided Phase II study of carboxyamido-triazole in androgen-independent prostate cancer. 1049

This is a brief outline of just a few promising strategies which clinical cancer research may be expected to concentrate upon in the course of the forthcoming decades. As far as treatment is concerned, radiotherapists are investing considerable effort in the development of three-dimensional conformal techniques, the superior precision of which may permit higher (and probably more effective) target doses without unacceptable normal tissue damage. For medical oncology, some of the newer angiogenesis inhibitors have shown great experimental potential and clinical trials with proteins such as angiostatin and endostatin are being planned for the near future. Simultaneously, increasing numbers of large clinical studies are testing what various micronutrients can (or cannot) do for prevention. Their importance has been suggested by a long series of epidemiologic observations but direct clinical proof is still very scantly. In only one of the 4 intervention studies mentioned in the text, was the result as expected. Antiestrogens may well have brought breast cancer prevention much nearer as a clinical proposition. Prostate cancer intervention studies have only just begun, but even their rationale is backed by data in experimental animals.
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PMID:[Waiting for the break through: a few tentative scenarios for cancer prevention and treatment in the coming decades]. 1050 Apr 73

A transgenic mouse model was used to evaluate the effect of endostatin treatment on spontaneous tumorigenesis. In this model system, female mice develop multiple mammary adenocarcinomas and male mice develop prostate cancer. Female mice treated with mouse endostatin during a 12-15-week period showed delayed tumor development by 4-6 weeks and significantly decreased tumor burden. Furthermore, endostatin treatment reduced the number of malignant lesions per mouse. In a separate set of experiments, male mice treated with endostatin showed a survival advantage, and their life spans were prolonged by 10.5 weeks over control animals. These data demonstrate that mouse endostatin is effective in delaying spontaneous tumor development and growth.
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PMID:Effect of endostatin on spontaneous tumorigenesis of mammary adenocarcinoma in a transgenic mouse model. 1096 78

Components of vascular basement membrane are involved in regulating angiogenesis. Recently, tumstatin (the NC1 domain of alpha3 chain of type IV collagen) was identified as possessing anti-angiogenic activity. In the present study, the anti-angiogenic activity of tumstatin was localized to the putative 54-132-amino acid Tum-5 domain, and the activity mediated by alpha(v)beta(3) integrin interaction in an RGD-independent manner. The recombinant Tum-5 produced in Escherichia coli and Pichia Pastoris specifically inhibited proliferation and caused apoptosis of endothelial cells with no significant effect on nonendothelial cells. Tum-5 also inhibited tube formation of endothelial cells on Matrigel and induced G1 endothelial cell cycle arrest. Moreover, anti-angiogenic effect of Tum-5 was also examined in vivo using both a Matrigel plug assay in C57BL/6 mice and human prostate cancer (PC-3) xenografts in nude mice. The in vivo results demonstrate that Tum-5 at 1 mg/kg significantly inhibited growth of PC-3 tumors in association with a decrease in CD31 positive vasculature. These in vivo studies also show that, at molar equivalents, human Tum-5 is at least 10-fold more active than human endostatin. In addition, these studies for the first time suggest that through the action of endogenous inhibitors, alpha(v)beta(3) integrin may also function as a negative regulator of angiogenesis. Taken together, these findings demonstrate that Tum-5, a domain derived from tumstatin, is an effective inhibitor of tumor-associated angiogenesis and a promising candidate for the treatment of cancer.
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PMID:Identification of the anti-angiogenic site within vascular basement membrane-derived tumstatin. 1127 65

We have performed association studies between a novel coding single nucleotide polymorphism (D104N) in endostatin, one of the most potent inhibitors of angiogenesis, and prostate cancer. We observed that heterozygous N104 individuals have a 2.5 times increased chance of developing prostate cancer as compared with homozygous D104 subjects (odds ratio, 2.4; 95% confidence interval, 1.4-4.16). Modeling of the endostatin mutant showed that the N104 protein is stable. These results together with the observation that residue 104 is evolutionary conserved lead us to propose that: (a) the DNA segment containing this residue might contain a novel interaction site to a yet unknown receptor; and (b) the presence of N104 impairs the function of endostatin.
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PMID:A polymorphism in endostatin, an angiogenesis inhibitor, predisposes for the development of prostatic adenocarcinoma. 1160 64

The interaction between cancer cells and their microenvironment is a promising area for the development of novel therapeutic anti-cancer modalities. The formation of new blood vessels, angiogenesis, is an important step in cancer progression. Angiogenesis is a complex multistep process involving close orchestration of endothelial cells, extracellular matrix, and soluble factors. Essentially every step has been found to be regulated by inducers and inhibitors. Prostate cancer has the ability to produce angiogenic factors such as metalloproteinases, vascular endothelial growth factor, fibroblast growth factor 2, transforming growth factor-beta and cyclooxygenase-2. In several studies in prostate cancer an increased microvessel density is associated with poorer prognosis. On the other hand several endogenous inhibitors of angiogenesis have been described in prostate cancer e.g., angiostatin, endostatin, prostate specific antigen (PSA), thrombospondin-1, interleukin 10, interferons and retinoids. The expanding insight in the process of angiogenesis has resulted in a large number of pharmaceutical agents that have been tested in preclinical studies and are currently tested in clinical trials. These agents inhibit endothelial cell proliferation or migration and induce apoptosis. This ultimately will affect the formation of new vessels thereby inducing tumor dormancy. Because antiangiogenic treatment is cytostatic rather than cytotoxic, patients will need long-term therapy to prevent regrowth of the tumor. Prostate cancer is an ideal tumor for antiangiogenic studies because of the availability of a reliable tumor marker, PSA, the indolent clinical course of this cancer and the low rate of proliferation even in metastatic sites. Furthermore, clinical studies showed limited side effects, which is advantageous in this elderly patient group. Whether the ultimate antiangiogenic treatment is effective as a single agent or in combination with radiation therapy, chemotherapy or immunotherapy remains to be determined.
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PMID:Angiogenesis in prostate cancer: its role in disease progression and possible therapeutic approaches. 1243 18

The integrin receptor alphavbeta3 has been shown to play a critical role in several distinct processes, such as angiogenesis, osteoclast-mediated bone resorption and tumor metastasis. Its expression is upregulated in newly synthesized blood vessels produced in response to a variety of tumors and purified angiogenic factors. Studies show that alphavbeta3 is a critical target downstream from perhaps all angiogcnic factors. Proof-of-principle that alphavbeta3 antagonists such as monoclonal antibodies and small molecules block angiogenesis and tumor growth has been obtained in several animal models. Many endogenous inhibitors of angiogenesis such as angiostatin, endostatin and tumstatin seem to work through the alphavbeta3 receptor further emphasizing the critical role of this receptor in angiogenesis. In addition, the alphavbeta3 receptor has been clearly implicated in several pathological processes such as rheumatoid arthritis, osteoporosis, and metastasis of prostate cancer to bone. Thus alphavbeta3 may prove to be an important target for pharmacological intervention in more than one clinical setting.
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PMID:Integrin alpha v beta 3 as a therapeutic target for blocking tumor-induced angiogenesis. 1255 65

In recent decades, radiation research has concentrated primarily on the cancer cell compartment. Much less is known about the effect of ionizing radiation on the endothelial cell compartment and the complex interaction between tumor cells and their microenvironment. Here we report that ionizing radiation is a potent antiangiogenic agent that inhibits endothelial cell survival, proliferation, tube formation and invasion. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor were able to reduce the radiosensitivity of endothelial cells. Yet, it is also found that radiation induces angiogenic factor production by tumor cells that can be abrogated by the addition of antiangiogenic agents. Receptor tyrosine kinase inhibitors of Flk-1/KDR/VEGFR2, FGFR1 and PDGFR beta, SU5416, and SU6668 enhanced the antiangiogenic effects of direct radiation of the endothelial cells. In a coculture system of PC3 prostate cancer cells and endothelial cells, isolated irradiation of the PC3 cells enhanced endothelial cell invasiveness through a Matrigel matrix, which was inhibited by SU5416 and SU6668. Furthermore, ionizing radiation up-regulated VEGF and basic fibroblast growth factor in PC3 cells and VEGFR2 in endothelial cells. Together these findings suggest a radiation-inducible protective role for tumor cells in the support of their associated vasculature that may be down-regulated by coadministration of angiogenesis inhibitors. These results rationalize concurrent administration of angiogenesis inhibitors and radiotherapy in cancer treatment.
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PMID:SU5416 and SU6668 attenuate the angiogenic effects of radiation-induced tumor cell growth factor production and amplify the direct anti-endothelial action of radiation in vitro. 1283 71

Endostatin has been considered a highly specific inhibitor of endothelial cell proliferation and/or migration. To explore the use of endostatin in antiangiogenic gene therapy, we generated a recombinant adenovirus, AdEndo, carrying the gene for mouse endostatin. Injection of 10(9) PFU of AdEndo resulted in a low but significant suppression (25%) of preestablished tumor growth in murine models involving murine Lewis lung carcinoma (LLC) and human breast cancer MDA-MB-231 tumors. Greater anticancer activity was observed when the same dose of AdEndo was injected into two other preestablished murine models involving C51 murine colon cancer and HT29 human colon cancer (55 and 47% tumor growth reduction, respectively). In vitro, endostatin derived from AdEndo-infected MRC-5 fibroblasts inhibited the growth of C51 and HT29 cell lines (72 and 61%, respectively). The extent of this inhibition was comparable to that observed in endothelial cells: 75% for microcapillary endothelial cell line HMEC-1, 52% for human dermal microvascular endothelial cells, 46% for human umbilical vein endothelial cells, and 67% for calf pulmonary arterial endothelial cells. Both endothelial and colon cancer cells showed a clear increase in cell apoptosis (4- to 5-fold for endothelial cells and 5- to 10-fold for colon cancer cells) and an accumulation in the G(1) phase of the cell cycle. This antiproliferative activity was not observed in other tumor cell lines: LLC, MDA-MB-231, murine colon adenocarcinoma MC38, human prostate cancer cell line DU145, and human breast cancer cell line CAL51. Taken together, these results provide evidence that, in addition to its antiangiogenic activity, endostatin exerts a direct anticancer action that appears to be restricted to some tumor cell lines. Thus, endostatin could be used in some colon cancer treatments and its clinical efficacy would depend on the response of tumor cells themselves.
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PMID:Endostatin exhibits a direct antitumor effect in addition to its antiangiogenic activity in colon cancer cells. 1286 17


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