Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C1519670 (tumor angiogenesis)
 6,052 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clear-cell renal cell carcinoma is characterized by the inactivation of the von Hippel-Lindau tumor suppressor gene, which results in an overproduction of vascular endothelial growth factor that promotes tumor angiogenesis, growth, and metastasis after binding with its receptor. The mammalian target of rapamycin signal transduction pathway is involved in the translation of hypoxia inducible factor-1 and vascular endothelial growth factor. Sunitinib, sorafenib, bevacizumab, and temsirolimus have improved clinical outcomes by inhibiting these tumorigenic pathways. Other multitargeted tyrosine kinase inhibitors (lapatinib, axitinib, pazopanib) and antiangiogenic agents (lenalidomide) have also demonstrated activity in early studies. Combinations of these agents are being evaluated. Clinical trials designed to further assess these and other agents need to be vigorously supported.
 ...
PMID:Targeting growth factor and antiangiogenic pathways in clear-cell renal cell carcinoma: rationale and ongoing trials. 1723 82

The zebrafish (Danio rerio)/tumor xenograft model represents a powerful new model system in cancer. Here, we describe a novel exploitation of the zebrafish model to investigate tumor angiogenesis, a pivotal step in cancer progression and target for antitumor therapies. Human and murine tumor cell lines that express the angiogenic fibroblast growth factor (FGF) 2 and/or vascular endothelial growth factor (VEGF) induce the rapid formation of a new microvasculature when grafted close to the developing subintestinal vessels of zebrafish embryos at 48 h postfertilization. Instead, no angiogenic response was exerted by related cell clones defective in the production of these angiogenic growth factors. The newly formed blood vessels sprout from the subintestinal plexus of the zebrafish embryo, penetrate the tumor graft, and express the transcripts for the zebrafish orthologues of the early endothelial markers Fli-1, VEGF receptor-2 (VEGFR2/KDR), and VE-cadherin. Accordingly, green fluorescent protein-positive neovessels infiltrate the graft when tumor cells are injected in transgenic VEGFR2:G-RCFP zebrafish embryos that express green fluorescent protein under the control of the VEGFR2/KDR promoter. Systemic exposure of zebrafish embryos immediately after tumor cell injection to prototypic antiangiogenic inhibitors, including the FGF receptor tyrosine kinase inhibitor SU5402 and the VEGFR2/KDR tyrosine kinase inhibitor SU5416, suppresses tumor-induced angiogenesis without affecting normal blood vessel development. Accordingly, VE-cadherin gene inactivation by antisense morpholino oligonucleotide injection inhibits tumor neovascularization without affecting the development of intersegmental and subintestinal vessels. These data show that the zebrafish/tumor xenograft model represents a novel tool for investigating the neovascularization process exploitable for drug discovery and gene targeting in tumor angiogenesis.
 ...
PMID:Mammalian tumor xenografts induce neovascularization in zebrafish embryos. 1740 96

ZD6474 is a novel, orally available inhibitor of vascular endothelial growth factor receptor kinase insert domain receptor/flk-1 tyrosine kinase activity with additional activity against the epidermal growth factor receptor-1 tyrosine kinase. The aim of this study was to evaluate ZD6474, alone and in combination with gemcitabine, in an orthotopic model of metastatic pancreatic cancer. Nude mice (nine to 10/group) were injected orthotopically with 1x10(6) L3.6pl human pancreatic cancer cells. Eight days later, treatment was initiated with vehicle only, gemcitabine (100 mg/kg intraperitoneal twice weekly), ZD6474 (50 mg/kg oral once daily) or a combination of the two treatments. Animals were killed on day 24 posttreatment initiation. The phosphorylation status level of vascular endothelial growth factor receptor-2 and epidermal growth factor receptor as well as the phosphorylation level of AKT and extracellular signal-regulated kinase-1/2 in different human pancreatic carcinoma cells and in human umbilical vein endothelial cells was analyzed by Western blotting. Compared with controls (1231 mg), the mean weight of treated tumors was reduced to 836, 541 and 308 mg in the gemcitabine, ZD6474 and combination groups, respectively. Lymph node metastasis was significantly reduced in both the ZD6474 alone and combined treatment groups, with 3/10 and 1/5 animals developing metastases, compared with 10/10 and 9/9 in the control and gemcitabine groups (P<0.003 and <0.0003, respectively). Microvessel density and cell proliferation were significantly reduced in the ZD6474 and combined treatment groups (P<0.02). Immunohistochemistry of tumor samples following treatment with ZD6474 resulted in a reduction of the activated and phosphorylated epidermal growth factor receptor, whereas total epidermal growth factor receptor levels were comparable with control tumors. On the basis of Western blot analysis, ZD6474 provides inhibition of tumor angiogenesis through an anti-vascular endothelial growth factor receptor-2 mechanism and inhibition of cancer cell growth through an anti-epidermal growth factor receptor mechanism. ZD6474 decreased primary pancreatic tumor growth and reduced lymph node and liver metastases compared with controls or gemcitabine alone. Tumor growth was inhibited further in animals receiving ZD6474 and gemcitabine in combination.
 ...
PMID:Antiangiogenic and antitumor activity of a novel vascular endothelial growth factor receptor-2 tyrosine kinase inhibitor ZD6474 in a metastatic human pancreatic tumor model. 1741 26

Therapies targeted on cell signal pathways that control cell division and tumor angiogenesis have been developed over the last five years for non small cell lung cancer (NSCLC) with some amazing results, in subgroups of selected patients, predicting more significant success in the upcoming years. Compounds targeted on EGF tyrosine kinase receptor have been tested in large clinical phase 2 and 3 trials including thousands of patients. Their efficacy has been proved, in second and third line trials, after first line cisplatin-based chemotherapy for non-mucinous adenocarcinoma in non-smokers, women and Asian patients. Response rates vary from 10% in non selected Caucasian patients to 40% in non-smoking Asian patients with long survivals. Therapeutic targeting improves success rates, either relying on EGFR gene amplification detection by FISH, or search for EGFR tyrosine kinase domain mutations. Commercial kits are available for routine molecular diagnosis of domain mutations potentially enabling molecular targeting in addition to clinical targeting. Angiogenesis inhibitors, especially monoclonal antibody to VEGF, bevacizumab, have also been developed in the last few years. Bevacizumab associated with classical cytotoxic chemotherapy led, in selected patients (with non squamous cell lung cancer and no past history of cardiovascular disease) to an increase of median survival to more than 12 months with tolerable toxicity. Other drugs that have both anti-EGFR activity and anti-angiogenic properties will be soon developed, since future bioactive anti-cancer drugs will probably be multi-targeted drugs.
 ...
PMID:[New biological treatments for lung cancer]. 1745 80

Vascular endothelial growth factor (VEGF) is one of the most important factors involved in tumor angiogenesis and has become an important target for anticancer treatment. In 2004, this approach was validated in a randomized, controlled phase III clinical trial. It was shown that the addition of bevacizumab, a humanized monoclonal antibody against VEGF-A, to conventional chemotherapy prolonged survival over chemotherapy alone in patients with metastatic colorectal cancer. In this review, we discuss the results of the clinical trials that have led to the incorporation of antiangiogenic agents into the treatment of patients with advanced colorectal cancer. We limit ourselves to the two agents that have been tested extensively in phase III trials: bevacizumab and vatalanib, a small molecule tyrosine kinase inhibitor against VEGF receptors. In addition, we discuss the adverse effects of bevacizumab and vatalanib and the clinical management of the side effects.
 ...
PMID:Target practice: lessons from phase III trials with bevacizumab and vatalanib in the treatment of advanced colorectal cancer. 1747 Jun 87

Expression of cyclooxygenase-2 (COX-2) has been linked to many cancers and may contribute to malignant phenotypes, including enhanced proliferation, angiogenesis, and resistance to cytotoxic therapies. Malignant gliomas are highly aggressive brain tumors that display many of these characteristics. One prominent molecular abnormality discovered in these astrocytic brain tumors is alteration of epidermal growth factor (EGF) receptor (EGFR) through gene amplification and/or mutation resulting in excessive signaling from this receptor. We found that EGF-mediated stimulation of EGFR tyrosine kinase in human glioma cell lines induces expression of both COX-2 mRNA and protein. The p38 mitogen-activated protein kinase (p38-MAPK) pathway was a strong downstream factor in this activation with inhibition of this pathway leading to strong suppression of COX-2 induction. The p38-MAPK pathway can activate the Sp1/Sp3 transcription factors and this seems necessary for EGFR-dependent transactivation of the COX-2 promoter. Analysis of COX-2 promoter/luciferase constructs revealed that transcriptional activation of the COX-2 promoter by EGFR requires the Sp1 binding site located at -245/-240. Furthermore, Sp1/Sp3 binding to this site in the promoter is enhanced by EGFR activation both in vitro and in vivo. Enhanced DNA binding by Sp1/Sp3 requires p38-MAPK activity and correlates with increased phosphorylation of the Sp1 transcription factor. Thus, EGFR activation in malignant gliomas can transcriptionally activate COX-2 expression in a process that requires p38-MAPK and Sp1/Sp3. Finally, treatment of glioma cell lines with prostaglandin E2, the predominant product of COX-2 activity, results in increased vascular endothelial growth factor expression, thus potentially linking elevations in COX-2 expression with tumor angiogenesis in malignant gliomas.
 ...
PMID:EGFR activation results in enhanced cyclooxygenase-2 expression through p38 mitogen-activated protein kinase-dependent activation of the Sp1/Sp3 transcription factors in human gliomas. 1761 68

The vascular endothelial growth factor (VEGF) family members are essential mediators of tumor angiogenesis. The multiple functions of the VEGFs are mediated through complex interactions between their ligands, the high-affinity tyrosine kinase receptors, and co-receptors (neuropilins). Emerging evidence has shown that these receptors, formerly described as being exclusively expressed on endothelial cells, are also expressed on a number of nonendothelial cells, including tumor cells. Moreover, it has been shown that their receptors (VEGFRs) are functional in a number of nonendothelial systems, where they can serve as targets for anti-VEGF therapy. As the expression of VEGFRs on tumor cells contributes to the understanding of the complex roles of VEGF within the tumor microenvironment and elucidation of VEGF activity might further refine antineoplastic regimens, this article will review the main effects and selective interactions of the VEGFRs, the evidence for their expression and function on tumor cells, and the direct efforts of anti-VEGF therapy on tumor cells.
 ...
PMID:The direct effects of anti-vascular endothelial growth factor therapy on tumor cells. 1768 Nov 2

Based on the background that hepatocyte growth factor (HGF) and Met/HGF receptor tyrosine kinase play a definite role in tumor invasion and metastasis, NK4 was isolated as a competitive antagonist against functional association between HGF and Met. NK4 is an internal fragment of HGF and composed of the N-terminal and four kringle domains. Independently on its HGF-antagonist action, NK4 inhibited angiogenesis induced by vascular endothelial cell growth factor and basic fibroblast growth factor, as well as HGF, indicating that NK4 is a bifunctional molecule that acts as an HGF-antagonist and angiogenesis inhibitor. In experimental models of distinct types of cancers, NK4 gene therapy inhibited Met receptor activation and this was associated with inhibition of tumor invasion and metastasis. Likewise, NK4 gene therapy inhibited tumor angiogenesis, thereby suppressing angiogenesis-dependent tumor growth. Cancer treatment with NK4 suppresses malignant tumors to be 'static' in both tumor growth and spreading. NK4 warrants further investigation and attention as potential cancer therapy for humans.
 ...
PMID:NK4 gene therapy targeting HGF-Met and angiogenesis. 1798 81

Glioblastoma multiforme (GBM) is the most aggressive form of brain tumor characterized by excessive angiogenesis. The dismal prognosis of patients with GBM warrants the development of new targeting therapies based on novel molecular markers. The EphA2 receptor tyrosine kinase plays a pivotal role in tumor angiogenesis and an increased expression in glioma patients has recently been reported. In this study, we investigated the expression of EphA2 in human normal brain, primary and recurrent GBM and correlated it with clinical pathological parameters and patient's outcome. In addition, intratumor microvascular density was quantified by immunostaining for the endothelial cell marker, von Willebrand factor. A different intensity of the membranous and cytoplastic expression of EphA2 was observed in the 40 primary and recurrent samples of GBM analyzed but not in the normal brain. A high level expression of EphA2 was demonstrated in 24 (60%) of the primary and recurrent GBM analyzed. The increased expression of the EphA2 protein was significantly associated with the adverse outcome of GBM patients (p<0.01 for overall survival). The data presented in this study define the expression pattern of EphA2 in both primary and recurrent glioblastoma and suggest an important role of EphA2 in the pathogenesis of GBM. The EphA2 may be used as a surrogate marker to screen patients for tyrosine kinase inhibitor therapy.
 ...
PMID:Increased expression of EphA2 correlates with adverse outcome in primary and recurrent glioblastoma multiforme patients. 1809 89

We assessed the antitumor efficacy of KRN951, a novel tyrosine kinase inhibitor of vascular endothelial growth factor receptors, using a rat colon cancer RCN-9 syngeneic model in which the tumor cells are transplanted into the peritoneal cavity of F344 rats. KRN951 treatments that commenced 4 days after tumor transplantation (day 4) significantly inhibited tumor-induced angiogenesis, the formation of tumor nodules in the mesenteric windows, and the accumulation of malignant ascites. Moreover, KRN951 treatments initiated on day 14, by which time angiogenesis and malignant ascites have already been well established, resulted in the regression of newly formed tumor vasculatures with aberrant structures and also in the apparent loss of malignant ascites by the end of the study period. Quantitative analysis of the vessel architecture on mesenteric windows revealed that KRN951 not only regressed, but also normalized the tumor-induced neovasculature. Continuous daily treatments with KRN951 significantly prolonged the survival of rats bearing both early stage and more advanced-stage tumors, compared with the vehicle-treated animals. The results of our current study thus show that KRN951 inhibits colon carcinoma progression in the peritoneal cavity by blocking tumor angiogenesis, ascites formation, and tumor spread, thereby prolonging survival. Moreover, these studies clearly demonstrate the therapeutic effects of KRN951 against established tumors in the peritoneal cavity, including the regression and normalization of the tumor neovasculature. Our findings therefore suggest that KRN951 has significant potential as a future therapeutic agent in the treatment of peritoneal cancers with ascites.
 ...
PMID:Anti-tumor activity and tumor vessel normalization by the vascular endothelial growth factor receptor tyrosine kinase inhibitor KRN951 in a rat peritoneal disseminated tumor model. 1820 Dec 72


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>