Regression of Human Breast Carcinoma in Nude Mice after Ad Gene Therapy Is Mediated by Tumor Vascular Endothelial Cell Apoptosis.

Two vascular endothelial growth factor (VEGF) receptors, FLT-1 and KDR, are expressed preferentially in proliferating endothelium. There is increasing evidence that recombinant, soluble VEGF receptor domains interfering with VEGF signaling may inhibit in vivo neoangiogenesis, tumor growth and metastatic spread. We hypothesized that a soluble form of FLT-1 receptor (sFLT-1) could inhibit the growth of pre-established tumors via an anti-angiogenic mechanism.

Differential gene expression in response to ventricular unloading in rat and human myocardium.

Unlabelled: Left ventricular unloading by mechanical assist devices induces myocardial atrophy. We aimed to systematically identify differentially expressed genes in a model of physiological atrophy (unloading of healthy rat myocardium) and compare these changes to those in a unloaded, failing human heart.

Methods: Atrophy in rat hearts was induced by heterotopic transplantation of a donor heart into the abdomen of an isogenic recipient.

Targeting vascular endothelial growth factor pathway offers new possibilities to counteract microvascular disturbances during ischemia/reperfusion of the pancreas.

Background: It is of crucial importance to explore new therapeutic strategies capable of combating or even preventing pancreatic graft failure after transplantation caused by ischemia reperfusion damage. So far, the role of the hypoxia induced mediator vascular endothelial growth factor (VEGF) upon pancreatic microcirculation has not been described. Therefore the aim of this study was to investigate its influence, using the novel tyrosinekinase inhibitor PTK787/ZK222584 (PTK/ZK), upon functional capillary density (FCD), leukocyte-endothelium interaction (LEI), and macromolecular permeability (P) of normal and postischemic pancreas tissue.

Subtractive hybridization for differential gene expression in mechanically unloaded rat heart.

The objective of this study was to identify differentially expressed genes in the mechanically unloaded rat heart by suppression subtractive hybridization. In male Wistar-Kyoto rats, mechanical unloading was achieved by infrarenal heterotopic heart transplantation. Differentially expressed genes were investigated systematically by suppression subtractive hybridization.

Design, synthesis, and biological evaluation of 3,4-diarylmaleimides as angiogenesis inhibitors.

The new analogue 2 of combretastatin A-4 was discovered to be an inhibitor of tubulin polymerization with an IC50 of 7.6 microM and reduced angiogenesis in the in vivo chick embryo model. Interestingly, in a series of 2,3-diarylmaleimides closely related to this lead, no other compound was found to be active in the tubulin polymerization assay.

Phase I clinical and pharmacokinetic study of PTK/ZK, a multiple VEGF receptor inhibitor, in patients with liver metastases from solid tumours.

The family of VEGF receptors are important mediators of angiogenesis, which is essential for tumour growth and metastasis. PTK/ZK is a multiple VEGF receptor inhibitor that blocks the activity of all known VEGF receptor tyrosine kinases. This phase I/II trial evaluated the safety, pharmacokinetics and efficacy of PTK/ZK in patients with liver metastases from solid tumours.

A single local injection of recombinant VEGF receptor 2 but not of Tie2 inhibits retinal neovascularization in the mouse.

Purpose: The purpose of this study was to develop pharmacological therapeutic alternatives for ischemia-induced proliferative retinopathy.

Methods: C57BL/6J mice were placed in 76% oxygen on postnatal day 7 (P7) for 5 days. On P12 recombinant, chimeric vascular endothelial growth factor (sVEGF-R2) or sTie2 was injected intravitreally in one eye.

Soluble markers for the assessment of biological activity with PTK787/ZK 222584 (PTK/ZK), a vascular endothelial growth factor receptor (VEGFR) tyrosine kinase inhibitor in patients with advanced colorectal cancer from two phase I trials.

Background: Plasma and serum biomarkers of angiogenesis and activated endothelial cells were evaluated to assess biological activity of PTK787/ZK 222584 (PTK/ZK), a novel oral angiogenesis inhibitor targeting all known vascular endothelial growth factor (VEGF) receptor tyrosine kinases.

Patients And Methods: Patients with colorectal cancer (CRC) (n=63) were enrolled into two phase I/II dose escalation trials of PTK/ZK in 28-day cycles until discontinuation. Patients with stable disease for > or =2 months were categorized as 'non-progressors'.

Differentiation and definition of vascular-targeted therapies.

The therapeutic potential of targeting the tumor vascular supply is now widely recognized. Intense research and development activity has resulted in a variety of investigational agents, a number of which are currently in clinical development. As these novel agents are quite distinct from the cytotoxic drugs conventionally used in the treatment of solid tumors, it will be particularly important to ensure early differentiation of these vascular-targeted therapies in order to encourage widespread understanding of their potential benefits and application in the clinic.

Changes in serum soluble VEGFR-1 and Tie-2 receptors in colorectal cancer patients following surgical resections.

Aim: Determination of changes in serum levels of soluble (s) VEGFR-1 and Tie-2 receptors in colorectal cancer patients following resection in the search for novel tumour markers.

Patients And Methods: Forty-five patients with primary colorectal cancer and 29 normal subjects were recruited. Serum sVEGFR-1 and sTie-2 receptors were assayed using ELISA.

Activated Neu/ErbB-2 induces expression of the vascular endothelial growth factor gene by functional activation of the transcription factor Sp 1.

The neu (c- erbB-2 or HER2 ) proto-oncogene which encodes a receptor protein homologous to the epidermal growth factor receptor is overexpressed in 20%-30% of human breast and ovarian cancers. Oncogenic activation of Neu can also occur through multiple molecular mechanisms, including a point mutation in the transmembrane domain, deletion of the extracellular domain and short in-frame deletions of 7-12 amino acids in the extracellular region proximal to the transmembrane domain. Because of the highly vascularized phenotype of breast and ovarian cancers and the contribution of the Neu receptor to the development and progression of these tumors, we investigated the effect of Neu on the expression of the tumor angiogenesis factor VEGF.

Expression of angiopoietin-2 in endothelial cells is controlled by positive and negative regulatory promoter elements.

Objective: Angiopoietin-2 (Ang-2) is a non-signal transducing ligand of the endothelial receptor tyrosine kinase Tie-2. Ang-2 is produced by endothelial cells and acts as an autocrine regulator mediating vascular destabilization by inhibiting Angiopoietin-1-mediated Tie-2 activation. To examine the transcriptional regulation of Ang-2, we studied the Ang-2 promoter in endothelial cells and nonendothelial cells.

Antiangiogenic potency of various chemotherapeutic drugs for metronomic chemotherapy.

From previous preclinical findings continuous low dose (metronomic) chemotherapy is thought to inhibit tumor angiogenesis. This suggests that activated endothelial cells may be more sensitive to chemotherapeutic drugs than tumor cells. Therefore, we assessed the IC50 for several relevant chemotherapeutic drugs in different endothelial and tumor cell lines to identify optimal compounds to be used for metronomic therapy in a murine renal cell carcinoma model.

Inhibition of tumor growth and angiogenesis by soluble EphB4.

EphB receptors and their ephrinB ligands play a key role in the formation of a regular vascular system. Recent studies have also shown the involvement of Eph/ephrin interactions in malignant tumor progression and angiogenesis. We have generated soluble monomeric EphB4 (sEphB4)-expressing A375 melanoma cells to study the effect of dominant negatively acting sEphB4 on tumor growth and angiogenesis.

Dynamic contrast-enhanced magnetic resonance imaging as a biomarker for the pharmacological response of PTK787/ZK 222584, an inhibitor of the vascular endothelial growth factor receptor tyrosine kinases, in patients with advanced colorectal cancer and liver metastases: results from two phase I studies.

Purpose: PTK787/ZK 222584 (PTK/ZK), an orally active inhibitor of vascular endothelial growth factor (VEGF) receptor tyrosine kinases, inhibits VEGF-mediated angiogenesis. The pharmacodynamic effects of PTK/ZK were evaluated by assessing changes in contrast-enhancement parameters of metastatic liver lesions using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in patients with advanced colorectal cancer treated in two ongoing, dose-escalating phase I studies.

Patients And Methods: Twenty-six patients had DCE-MRI performed at baseline, day 2, and at the end of each 28-day cycle.

Vascular endothelial growth factor and soluble Tie-2 receptor in colorectal cancer: associations with disease recurrence.

Aims: A delicate balance exists between pro-angiogenic factors and anti-angiogenic factors to regulate the process of angiogenesis. To investigate the relationship of VEGF-A with other angiogenic factors and to determine their clinical usefulness.

Methods: Venous blood was obtained from 47 patients with CRC prior to curative resections.

Implications of vascular endothelial growth factor, sFlt-1, and sTie-2 in plasma, serum and cerebrospinal fluid during cerebral ischemia in man.

The relation between cerebral ischemia and local release of angiogenic factors was investigated after subarachnoid hemorrhage (SAH) in humans. Time-dependent concentration-changes of vascular endothelial growth factor (VEGF), sFlt-1 and sTie-2 extracted from plasma, serum, and cerebrospinal fluid (ventricular, cisternal, and lumbar) were analyzed in 15 patients surgically treated for ruptured aneurysms of the anterior circulation (Hunt and Hess grades I-V). Data were related to brain Po2 (Pbro2) and cerebral energy metabolites (extracellular lactate, pyruvate, glutamate, and glycerin concentrations) as well as clinical and radiologic reference data.