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)

The effects of the angiogenic inhibitors endostatin, angiostatin, and TNP-470 on tumor growth dynamics are experimentally and theoretically investigated. On the basis of the data, we pose a quantitative theory for tumor growth under angiogenic stimulator/inhibitor control that is both explanatory and clinically implementable. Our analysis offers a ranking of the relative effectiveness of these inhibitors. Additionally, it reveals the existence of an ultimate limitation to tumor size under angiogenic control, where opposing angiogenic stimuli come into dynamic balance, which can be modulated by antiangiogenic therapy. The competitive influences of angiogenically driven growth and inhibition underlying this framework may have ramifications for tissue size regulation in general.
Cancer Res 1999 Oct 01
PMID:Tumor development under angiogenic signaling: a dynamical theory of tumor growth, treatment response, and postvascular dormancy. 1051 81

Endostatin, a potent inhibitor of angiogenesis and tumor growth, is a COOH-terminal fragment of collagen XVIII derived through cleavage of an Ala-His linkage by an as yet unidentified endostatin-processing enzyme. Endostatin was originally isolated from the conditioned medium of hemangioendothelioma (EOMA) cells. By investigating the processing of collagen XVIII to endostatin by EOMA cells, we show here that the generation of endostatin can be mediated by an elastase activity. We also show that several members of the elastase family can act as an endostatin-processing enzyme by specifically cleaving the Ala-His linkage and releasing endostatin from a precursor molecule. We further suggest that the generation of endostatin from collagen XVIII is at least a two-step process, involving a metal-dependent early step and an elastase activity-dependent final step.
Cancer Res 1999 Dec 15
PMID:The generation of endostatin is mediated by elastase. 1062 89

Angiogenesis is required for tumor formation. Several studies have demonstrated that tumor angiogenesis is regulated by a balance between proangiogenesis and antiangiogenesis factors and that this balance varies in different organ environments. To investigate whether expression of an angiogenesis inhibitor by cancer cells could alter this balance and prevent tumor formation in different organ environments, we engineered stable transfectants from RenCa mouse renal carcinoma cells and SW620 human colon carcinoma cells to constitutively secrete a mouse endostatin protein with c-myc and polyhistidine (His) tags. Production and secretion of the endostatin-c-myc-His fusion protein by endostatin-transfected cells were confirmed by immunofluorescence staining and Western blot analysis. The endostatin transfectants and control transfectants, stably transfected with a control plasmid, had similar in vitro growth rates compared with their parental cell lines. Conditioned medium from endostatin-transfected cells inhibited human umbilical vein endothelial cell proliferation by 36-51% compared with conditioned medium from control cells. After inoculation into mice, flank tumors from endostatin-transfected cells were 73-91% smaller than flank tumors from control cells after 3 weeks. Inoculation of a cell mixture containing 25% endostatin-transfected cells and 75% control cells resulted in inhibition of flank tumor formation as effective as after inoculation of 100% endostatin-transfected cells. Formation of lung metastases by RenCa endostatin-transfected cells and formation of liver metastases by SW620 endostatin-transfected cells were dramatically inhibited compared with formation of metastases by control cells. These findings demonstrate that endostatin can inhibit tumor formation in different organ environments and that gene delivery of endostatin into even a minority of tumor cells may be an effective strategy to prevent progression of micrometastases to macroscopic disease.
Cancer Res 1999 Dec 15
PMID:Mouse endostatin inhibits the formation of lung and liver metastases. 1062 20

Shortly before his death in 1995, Kenneth B. Schwartz, a cancer patient at Massachusetts General Hospital (MGH), founded The Kenneth B. Schwartz Center at MGH. The Schwartz Center is a non-profit organization dedicated to supporting and advancing compassionate health care delivery which provides hope to the patient, support to caregivers, and encourages the healing process. The center sponsors the Schwartz Center Rounds, a monthly multidisciplinary forum where caregivers reflect on important psychosocial issues faced by patients, their families, and their caregivers, and gain insight and support from fellow staff members. The September 1999 Schwartz Center Rounds addressed the growing attention around the phase I trial of Endostatin. Endostatin represents a new treatment paradigm. It is an anti-angiogenic protein, an endogenous fragment of collagen XVIII. In an attempt to ensure a fair allocation of a very limited number of treatment slots in this classical phase I trial, a lottery was established. More than 1,400 patients enrolled within two days of the lottery, all vying for three places in the first cohort. Two contrasting cases are presented, each a potentially eligible patient. The discussion focuses on the dilemma presented by patients desperate for an unproven treatment and the responsibility of staff to explain and support without compounding the hype or suffocating the hope.
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PMID:Reality testing in cancer treatment: the phase I trial of endostatin. 1063 94

Antiangiogenic therapy may represent a promising approach to cancer treatment. Indeed, the efficacy of endogenous angiogenesis inhibitors, including angiostatin, endostatin and TIMPs, has been demonstrated in many types of solid tumors in animal models. In view of the possible problems associated with long-term administration of inhibitors as recombinant proteins, we propose their delivery as nucleic acids through a gene therapy approach. To this end, eukaryotic expression constructs for murine angiostatin and endostatin as well as human TIMP-2 were generated, and characterized in vitro. All constructs carry the relevant cDNAs under the control of the strong HCMV promoter/enhancer, and cleavable leader signals to allow protein secretion. Expression of the angiogenesis inhibitors was detected by in vitro transcription/translation experiments as well as transfection of 293T cells, followed by Western blotting (WB) or radioimmunoprecipitation analysis of both cell lysates and supernatants (SNs). These constructs might be used for in vivo intramuscular delivery of plasmid DNA and as a set of reagents for the development of retroviral as well as adeno-associated viral (AAV) vectors expressing angiogenesis inhibitors.
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PMID:Generation of expression plasmids for angiostatin, endostatin and TIMP-2 for cancer gene therapy. 1066 55

We examined the effect on tumor growth, vessel morphology, and expression of angiogenic factors of combining radiotherapy and antiangiogenesis in the human glioblastoma line U87 grown in the flank or intracranially in the nude mouse. The antiangiogenic agent TNP-470 was given 6.7 mg/kg s.c. daily on day 1-7 starting 1 week after transplantation. Irradiation (IR), 10 Gy x 1, was administered on day 7. A series of tumors were excised 8 and 48 h after the end of treatment. The vascular morphology was evaluated in CD31 immunostained cryosections and by electron microscopy, and the pattern of expression of angiogenic factors (mRNA and protein) was quantitatively analyzed by phosphorimaging of Northern blots and Western blots. Significant inhibition of s.c. flank tumor growth relative to untreated controls was achieved by monotherapy with both TNP-470 (P < 0.001) and IR (P < 0.001). A significant enhancement of this effect was obtained by combining TNP-470 and IR (P < 0.05). We saw no effect of TNP-470 either alone or in addition to the effect of IR on the survival of mice with intracranial tumors. CD31 immunostaining of s.c. tumors showed acute endothelial swelling and luminal protrusion in irradiated tumor vessels but never in tumors pretreated with TNP-470, and not in the untreated controls. The vessel density (Chalkley point counts) was unchanged by TNP-470 therapy. In the TNP-470-treated tumors, we observed a distinct broadening of the endothelial basement membrane by an approximately 400-700-nm-thick electron-dense yet uncharacterized fibrillar material. TNP-470 treated tumors +/- IR also had a significantly increased mRNA expression of angiopoietin-1, whereas angiopoietin-2, vascular endothelial growth factor and basic fibroblast growth factor mRNA were unchanged by the treatments. In conclusion, TNP-470 significantly enhanced the tumor effect of ionizing IR, and our findings strongly indicate that acute microvascular damage after IR is effectively prevented by concurrent TNP-470 treatment. A significant up-regulation of angiopoietin-1 seems to play a role in this protective mechanism, which as yet is not fully elucidated.
Clin Cancer Res 2000 Mar
PMID:Therapeutic synergy of TNP-470 and ionizing radiation: effects on tumor growth, vessel morphology, and angiogenesis in human glioblastoma multiforme xenografts. 1074 23

Gene therapy represents a possible alternative to the chronic delivery of recombinant antiangiogenic proteins to cancer patients. Inducing normal host tissues to produce high circulating levels of these proteins may be more effective than targeting antiangiogenic genes to tumor tissue specifically. Previously reported gene therapy approaches in mice have achieved peak circulating endostatin levels of 8-33 ng/ml. Here we report plasma endostatin levels of 1770 ng/ml after administration of a recombinant adenovirus. Growth of MC38 adenocarcinoma, which is relatively resistant to adenoviral infection, was inhibited by 40%. These findings encourage gene delivery approaches that use the host as a "factory" to produce high circulating levels of antiangiogenic agents.
Cancer Res 2000 Mar 15
PMID:Antiangiogenic gene therapy of cancer utilizing a recombinant adenovirus to elevate systemic endostatin levels in mice. 1074 12

Inhibition of angiogenesis has been shown to be an effective strategy in cancer therapy in mice. However, its widespread application has been hampered by difficulties in the large-scale production of the antiangiogenic proteins. This limitation may be resolved by in vivo delivery and expression of the antiangiogenic genes. We have constructed a recombinant adenovirus that expresses murine endostatin that is biologically active both in vitro, as determined in endothelial cell proliferation assays, and in vivo, by suppression of angiogenesis induced by vascular endothelial growth factor 165. Persistent high serum levels of endostatin (605-1740 ng/ml; mean, 936 ng/ml) were achieved after systemic administration of the vector to nude mice, which resulted in significant reduction of the growth rates and the volumes of JC breast carcinoma and Lewis lung carcinoma (P < 0.001 and P < 0.05, respectively). In addition, the endostatin vector treatment completely prevented the formation of pulmonary micrometastases in Lewis lung carcinoma (P = 0.0001). Immunohistochemical staining of the tumors demonstrated a decreased number of blood vessels in the treatment group versus the controls. In conclusion, the present study clearly demonstrates the potential of vector-mediated antiangiogenic gene therapy as a component in cancer therapy.
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PMID:Adenovirus-mediated gene transfer of endostatin in vivo results in high level of transgene expression and inhibition of tumor growth and metastases. 1075 66

BACKGROUND: There is extraordinary interest in developing angiosuppressive agents for cancer treatment. Several new agents appear promising for the treatment of a variety of human cancers. Current concepts and new agents in clinical trials are the focus of this article. In particular, the introduction of a new treatment for human brain tumors is presented in detail, using an antiangiogenic agent, penicillamine, and depletion of an obligatory cofactor of angiogenesis, copper. METHODS: The explosive increase in literature on antiangiogenesis is reviewed using computerized search, findings presented at the recent national cancer and angiogenesis meetings. A specific protocol, NABTT 97-04, "Penicillamine and Copper Reduction for Newly Diagnosed Glioblastoma," is presented as an example of angiotherapeutic drug discovery. RESULTS: A number of promising molecular approaches are being introduced to suppress tumor angiogenesis. Major categories of angiogenesis antagonists include protease inhibitors, direct inhibitors of endothelial cell proliferation and migration, suppression of angiogenic growth factors, inhibition of endothelial-specific integrin/ survival signaling, chelators of copper, and inhibitors with specific other mechanisms. The preliminary results of early trials offer a glimpse into how antiangiogenesis therapy will be integrated into future care of the patient with cancer. CONCLUSIONS: Thirty-five antiangiogenesis therapies are currently being evaluated in clinical trials. As we learn more about the fundamental mechanisms of angiogenesis, eg, the role of copper in growth factor activation, effective methods of cancer control will be implemented.
Cancer Control 1999 Oct
PMID:Angiogenesis and Cancer Control: From Concept to Therapeutic Trial. 1075 76

BACKGROUND: Many potential new antineoplastic agents are currently in various stages of clinical development. Three areas of drug development include antiangiogenic compounds, agents that inhibit matrix metalloproteinases, and agents that modulate cyclin-dependent kinases. METHODS: The authors reviewed the available data for endostatin, COL-3, and flavopiridol, each of which is being developed with one of the above-mentioned proposed mechanisms of action. These agents are among the first drugs to reach clinical testing that is focusing on these novel targets. RESULTS: Endostatin has finished preclinical testing and the first human trials are about to be initiated. COL-3 is in phase I testing in several locations. Phase I studies for flavopiridol have been completed and several phase II studies are underway. It is unknown at this point if any of these agents will provide clinical benefit to patients at doses that do not cause unacceptable toxicity. CONCLUSIONS: These agents are currently at various stages of clinical testing. Albeit promising as potential modulators in molecular and biochemical pathways, continued research is needed into the toxicities and clinical usefulness of these agents.
Cancer Control 1999 Oct
PMID:Review of Three New Agents That Target Angiogenesis, Matrix Metalloproteinases, and Cyclin-Dependent Kinases. 1075 77


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