Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017636 (glioblastoma)
 18,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using an orthotopic glioblastoma model, we investigated the activity of the combination of monoclonal antibody DC101 against vascular endothelial growth factor receptor-2 (VEGFR-2) and monoclonal antibody C225 against epidermal growth factor receptor (EGFR). Nude mice bearing intracerebral glioblastoma xenografts were administered either DC101 or C225, or the combination via intraperitoneal (i.p.) injection. Histopathological analysis of solid tumor volume, microvessel density, tumor cell proliferation and apoptosis were performed. In the DC101-treated group, solid tumor volume and microvessel density were reduced by 59.7% and 64%, respectively. The tumor cell proliferation level was reduced by 53.2% and tumor cell apoptosis was increased by 66.7% but there was enhanced tumor cell invasiveness. C225 alone reduced the invasiveness of tumor tissue, but had no effect on solid tumor growth, microvessel density, tumor cell proliferation or apoptosis. The combination cancer therapy with C225 and DC101 enhanced tumor treatment with reduced tumor volume, microvessel density, tumor cell proliferation level, and increased cancer cell apoptosis, while decreasing tumor cell invasiveness.
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PMID:Enhanced cancer therapy with the combination of EGFR and VEGFR-2 targeting in an orthotopic glioblastoma model. 2130 49

We determined the maximum tolerated dose (MTD) and dose-limiting toxicities (DLT) of the oral vascular endothelial growth factor receptor (VEGFR) inhibitor, sunitinib, when administered with irinotecan among recurrent malignant glioma (MG) patients. For each 42-day cycle, sunitinib was administered once a day for four consecutive weeks followed by a 2 week rest. Irinotecan was administered intravenously every other week. Each agent was alternatively escalated among cohorts of 3-6 patients enrolled at each dose level. Patients on CYP3A-inducing anti-epileptic drugs were not eligible. Twenty-five patients with recurrent MG were enrolled, including 15 (60%) with glioblastoma (GBM) and 10 (40%) with grade 3 MG. Five patients progressed previously on bevacizumab and two had received prior VEGFR tyrosine kinase inhibitor therapy. The MTD was 50 mg of sunitinib combined with 75 mg/m(2) of irinotecan. DLT were primarily hematologic and included grade 4 neutropenia in 3 patients and one patient with grade 4 thrombocytopenia. Non-hematologic DLT included grade 3 mucositis (n = 1) and grade 3 dehydration (n = 1). Progression-free survival (PFS)-6 was 24% and only one patient achieved a radiographic response. The combination of sunitinib and irinotecan was associated with moderate toxicity and limited anti-tumor activity. Further studies with this regimen using the dosing schedules evaluated in this study are not warranted.
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PMID:Phase I study of sunitinib and irinotecan for patients with recurrent malignant glioma. 2174 79

Tumor cell vasculogenic mimicry (VM) describes the functional plasticity of aggressive cancer cells forming de novo vascular networks, thereby providing a perfusion pathway for rapidly growing tumors, transporting fluid from leaky vessels, and/or connecting with endothelial-lined vasculature. The underlying induction of VM seems to be related to hypoxia, which may also promote the plastic, transendothelial phenotype of tumor cells capable of VM. Since its introduction in 1999 as a novel paradigm for melanoma tumor perfusion, many studies have contributed new insights into the underlying molecular pathways supporting VM in a variety of tumors, including melanoma, glioblastoma, carcinomas, and sarcomas. In particular, critical VM-modulating genes are associated with vascular (VE-cadherin, EphA2, VEGF receptor 1), embryonic and/or stem cell (Nodal, Notch4), and hypoxia-related (hypoxia-inducible factor, Twist1) signaling pathways. Each of these pathways warrants serious scrutiny as potential therapeutic, vascular targets, and diagnostic indicators of plasticity, drug resistance, and the aggressive metastatic phenotype.
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PMID:Molecular pathways: vasculogenic mimicry in tumor cells: diagnostic and therapeutic implications. 2247 19

Anti-angiogenic therapy is a promising therapeutic strategy for the highly vascular and malignant brain tumor, glioblastoma (GBM), although current clinical trials have failed to demonstrate an extension in overall survival. The small molecule tyrosine kinase inhibitor axitinib that targets vascular endothelial growth factor receptor, potently inhibits angiogenesis and has single-agent clinical activity in non-small cell lung, thyroid, and advanced renal cell cancer. Here we show that axitinib exerts direct cytotoxic activity against a number of patient-derived GBM stem cell (GSCs) and an endothelial cell line, and inhibits endothelial tube formation in vitro. Axitinib treatment of mice bearing hypervascular intracranial tumors generated from human U87 glioma cells, MGG4 GSCs and mouse 005 GSCs significantly extended survival that was associated with decreases in tumor-associated vascularity. We thus show for the first time the anti-angiogenic effect and survival prolongation provided by systemic single agent treatment with axitinib in preclinical orthotopic GBM models including clinically relevant GSC models. These results support further investigation of axitinib as an anti-angiogenic agent for GBM.
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PMID:Single agent efficacy of the VEGFR kinase inhibitor axitinib in preclinical models of glioblastoma. 2521 69

Neo-vascularization is a vital process for tumor growth and development which involves the interaction between tumor cells and stromal endothelial cells through several growth factors and membranous receptors which ultimately activate pro-angiogenic intracellular signaling pathways. Inhibition of angiogenesis has become a standard treatment option for several tumor types including colorectal cancer, glioblastoma and ovarian cancer. In gastric cancer, the therapeutic role of anti-angiogenic agents is more controversial. Bevacizumab and ramucirumab, two monoclonal antibodies, which target vascular endothelial growth factor-A and vascular endothelial growth factor receptor-2, respectively, have been demonstrated antitumor activity in patients with tumors of the stomach or esophagogastric junction. However, especially for bevacizumab, this antitumor activity has not consistently translated into a survival advantage over standard treatment in randomized trials. In this article, we provide an overview of the role of angiogenesis in gastric cancer and discuss the results of clinical trials that investigated safety and effectiveness of antiangiogenic therapies in this disease. A review of the literature has been done using PubMed, ClinicalTrials.gov website and the ASCO Annual Meeting Library.
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PMID:Anti-angiogenic therapies for advanced esophago-gastric cancer. 2553 1

Loss of the tumor suppressor phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a prerequisite for tumor cell-specific expression of vascular endothelial growth factor receptor (VEGFR)-2 in glioblastoma defining a subgroup prone to develop evasive resistance towards antiangiogenic treatments. Immunohistochemical analysis of human tumor tissues showed VEGFR-2 expression in glioma cells in 19% of specimens examined, mainly in the infiltration zone. Glioma cell VEGFR-2 positivity was restricted to PTEN-deficient tumor specimens. PTEN overexpression reduced VEGFR-2 expression in vitro, as well as knock-down of raptor or rictor. Genetic interference with VEGFR-2 revealed proproliferative, antiinvasive and chemoprotective functions for VEGFR-2 in glioma cells. VEGFR-2-dependent cellular effects were concomitant with activation of 'kappa-light-chain-enhancer' of activated B-cells, protein kinase B, and N-myc downstream regulated gene 1. Two-photon in vivo microscopy revealed that expression of VEGFR-2 in glioma cells hampers antiangiogenesis. Bevacizumab induces a proinvasive response in VEGFR-2-positive glioma cells. Patients with PTEN-negative glioblastomas had a shorter survival after initiation of bevacizumab therapy compared with PTEN-positive glioblastomas. Conclusively, expression of VEGFR-2 in glioma cells indicates an aggressive glioblastoma subgroup developing early resistance to temozolomide or bevacizumab. Loss of PTEN may serve as a biomarker identifying those tumors upfront by routine neuropathological methods.
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PMID:Glioma cell VEGFR-2 confers resistance to chemotherapeutic and antiangiogenic treatments in PTEN-deficient glioblastoma. 2568 71

Adnectins are a family of binding proteins derived from the 10th type III domain of human fibronectin (10Fn3), which is part of the immunoglobulin superfamily and normally binds integrin. The 10Fn3 has the potential for broad therapeutic applications given its structural stability, ability to be manipulated, and its abundance in the human body. The most commonly studied adnectin is CT-322, which is an inhibitor of vascular endothelial growth factor receptor-2. A bispecific adnectin, El-Tandem, has also been developed and binds to epidermal growth factor receptor and insulin-like growth factor-1 receptor simultaneously. Pre-clinical studies have shown promising results in relation to reducing tumor growth, decreasing microvessel density, and promoting normalization of tumor architecture. The phase I trial with CT-322 demonstrates relatively low toxicities. However, the phase II study done with CT-322 in recurrent glioblastoma does not reveal as promising results.
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PMID:Adnectin-targeted inhibitors: rationale and results. 2604 29

Gastric (GC) and gastroesophageal junction (GEJ) cancers are two global health problems with a relatively high mortality, particularly in the advanced stage. Inhibition of angiogenesis is now contemplated as a classic treatment preference for myriad tumor types encompassing renal cell carcinoma, non-small cell lung cancer, colorectal cancer, glioblastoma, and ovarian cancer, among others. Bevacizumab and ramucirumab have been widely investigated in GC and GEJ cancer, with some controversy about their therapeutic role. Ramucirumab is a monoclonal antibody for vascular endothelial growth factor receptor-2, with demonstrated activity both as a monotherapy and as a part of combination strategy in the management of advanced GC/GEJ cancer. In this review article, we present a critical evaluation of the preclinical and clinical data underlying the use of this drug in this indication. Moreover, we provide a spotlight on the future perspectives in systemic therapy for advanced GC/GEJ cancer.
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PMID:Critical evaluation of ramucirumab in the treatment of advanced gastric and gastroesophageal cancers. 2625 8

Bevacizumab (BV), a monoclonal antibody against vascular endothelial growth factor (VEGF), is currently used in the treatment of malignant glioma. To understand mechanisms of resistance to BV, we investigated morphological changes in tumor vessels and expression of angiogenic factors, such as VEGF, Flt-1, basic fibroblast growth factor (bFGF), and platelet-derived growth factor-BB (PDGF-BB), in four autopsied tumors after BV treatment. Three patients had glioblastomas; the fourth had a secondary glioblastoma that developed from a diffuse astrocytoma. BV was administered because of recurrence following the use of the Stupp regimen in these four patients. We compared the initial surgical specimen with that obtained after death following BV treatment. Immunohistochemical staining of the autopsied tumors showed that Flt-1 expression increased while VEGF expression was significantly reduced. Additionally, other angiogenic factors, particularly bFGF, were enhanced. Interestingly, the proliferation of endothelial cells was reduced, but remarkable proliferation of pericytes was observed. These results suggest that following BV treatment, glioblastomas can grow tumor vessels by expressing various angiogenic factors. These mechanisms might be important for rapid regrowth and blood brain barrier repair after BV treatment. Inhibition of multiple angiogenic factors will be required to control tumor vessels in glioblastoma.
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PMID:Bevacizumab changes vascular structure and modulates the expression of angiogenic factors in recurrent malignant gliomas. 2682 5

Glioblastoma, the most common primary malignant brain tumor in adults, is highly aggressive and associated with a poor prognosis. Bevacizumab, a monoclonal antibody against the vascular endothelial growth factor receptor, has increasingly been used in the treatment of recurrent glioblastoma. It has achieved excellent rates of radiographic response, but most patients will progress after only a few months. Upon recurrence, tumors may not enhance, secondary to vascular normalization. We describe four patterns of radiographic progression commonly associated with Bevacizumab failure: 1) Distant enhancing tumor, 2) Local tumor progression without enhancement, 3) Diffuse gliomatosis-like infiltration, and 4) Local or multifocal progression, with enhancement. Some have noted an increased incidence of distant or diffuse disease upon recurrence, suggestive of a transition to a more aggressive phenotype, but a review of the literature suggests there is no conclusive evidence that Bevacizumab treatment is associated with an increased rate of distant or diffuse recurrence.
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PMID:Bevacizumab in Recurrent Glioma: Patterns of Treatment Failure and Implications. 2851 72


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