Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hypoxia-inducible factor-1 (HIF-1) is a transcription factor first identified as being activated by hypoxia but also in normoxic conditions by insulin and IGF-2. It is able to induce the expression of glycolytic genes and hence the ATP production, it also regulates the expression of the angiogenic factor VEGF and stimulates erythropoiesis via EPO production. HIF-1 is a protein necessary for the normal embryonic and cardiovascular system development, but seems to be also involved in cancer progression and apoptosis. Thus, it appears that HIF-1 plays a central role in normal cellular functions and in tissue metabolism but it is also involved in pathological evolutions raising its interest as a therapeutic target. In this review, we summarize the dual role of HIF-1 as a major component of the embryo development, as well as an element of tumor progression and of anoxia-induced apoptosis.
Int J Mol Med 2000 Mar
PMID:Role of HIF-1 as a transcription factor involved in embryonic development, cancer progression and apoptosis (review). 1067 65

The quantitative measurement of gene expression requires consistent and reliable standards. At least two categories of standards, endogenous and exogenous, are currently used for quantitative PCR. The reliability of these two methods, however, has not been carefully compared. We hypothesized that a reliable quantitative PCR assay would be able to detect known dilutions of a given single-stranded (ss-) cDNA. By measuring VEGF ss-cDNA copy numbers or signal ratios of GAPDH/VEGF in 10x and 100x diluted samples of two original ss-cDNA preparations, an exogenous recombinant DNA standard (a VEGF-mimic plasmid) and an endogenously expressed GAPDH standard were tested for their ability to detect dilution factors. Using the recombinant DNA standard, the dilution factor was detected as 10.3 and 135.0 in 10x and 100x diluted samples of the original CaSki cell ss-cDNA, respectively. The detected dilution factors were 12.3 and 226.2, respectively, in 10x and 100x diluted ss-cDNA from U-251 MG cells. On the other hand, with the endogenous GAPDH standard, the dilution factors were detected as 2.7 and 8.0 in the same 10x and 100x dilutions of the original U-251 MG cell ss-cDNA. Using the same endogenous GAPDH standard, the detected dilution factors were both 4.8 in 10x and 100x dilutions of the original CaSki cell ss-cDNA. It was also found that the number of endogenous copies of GAPDH mRNA was about 1000 times higher than VEGF. The high internal lockup ratio of GAPDH vs VEGF copy numbers and the requirement for additional primer pairs make the use of an abundant endogenous standard an unreliable choice in quantitative or semi-quantitative PCR. In contrast, exogenous standard-based quantitative PCR was shown to be an accurate and reliable method for the quantitation of gene expression.
Mol Cell Probes 2000 Apr
PMID:A reliability test of standard-based quantitative PCR: exogenous vs endogenous standards. 1079 75

Numerous laboratories are focusing efforts on delivering gene products to induce or prevent the development of new blood vessels in adults, with the hope of rescuing ischemic tissues, circumventing cardiac bypass surgery, or inhibiting tumor growth. Current approaches to the assessment of vascular continuity involve the introduction of either dyes or fluorescent microspheres to track blood flow. However, dyes and dextrans are subject to leakage when vessels are hyperpermeable, a situation that may occur in studies of tumor vasculature and during efforts to stimulate therapeutic angiogenesis. Furthermore, the microspheres that are used for flow studies do not allow a comprehensive visual analysis of vascular continuity. Here we report a method for the visual assessment of microvascular continuity in mouse muscle under circumstances in which vessels are leaky. The approach involves perfusion of the vasculature with fluorescent beads that are much smaller than those used for flow studies. The suspension behaves like a fluid and completely fills the vessels, yet the beads do not leak from VEGF-permeablized capillaries and remain localized in histological sections. Use of beads with the proper fluorescence emission wavelengths allows immunofluorescent colocalization with vessel-specific markers. We compare this improved method with other methods for tracking vascular continuity involving dextrans and larger beads. This approach should aid in the dynamic study of tumor angiogenesis and the evaluation of efforts to deliver angiogenic factors.
Mol Ther 2000 Jan
PMID:Angiogenesis monitored by perfusion with a space-filling microbead suspension. 1093 15

Therapeutic angiogenesis, either by protein injection or gene therapy, holds considerable promise for the treatment of coronary and peripheral artery diseases. Given the large number of angiogenic genes available, a simple, well defined, standard system to compare the relative angiogenic efficacy of such genes would be valuable. We have employed a replication-deficient adenovirus vector (complete E1a-, partial E1b- and partial E3-) to deliver the beta-galactosidase (beta-gal, AdLacZ) reporter gene or the human VEGF121 gene (AdGV VEGF121.10) to a rat sponge implant model of angiogenesis. beta-gal staining results reveal a transfection efficiency as high as 60% 24 h after 2x1010 particle units AdLacZ injection. Our results also indicate that a single injection of 2x1010 particle units of AdGVVEGF121.10 in the sponge results in >10, 000 pg VEGF protein expression per milligram of sponge tissue 24 h later. VEGF121 protein concentrations decreased 10-fold within 3 days and 100-fold within 7 days after injection. Significant VEGF121 protein levels were still detectable 14 days after initial virus injection. The high level of gene transfection efficiency was accompanied by enhanced angiogenesis in the sponge, a tissue devoid of any vessels before implantation. Compared to control (AdNull: adenovirus vector without the VEGF gene), AdGVVEGF121.10 induced a 2- to 3-fold up-regulation of angiogenesis at 7 and 14 days post vector injection as determined by both increased capillary number and increased tissue ingrowth. The angiogenic effects of AdGVVEGF121. 10 were dose-related in this model system. These findings demonstrate a dose-related angiogenic response to adenovirus-mediated gene therapy in this model.
Int J Mol Med 2000 Dec
PMID:Rat sponge implant model: a new system for evaluating angiogenic gene transfer. 1107 23

Many similarities exist in the cellular responses elicited by VEGF and governed by integrins. Here, we identify a basis for these interrelationships: VEGF activates integrins. VEGF enhanced cell adhesion, migration, soluble ligand binding, and adenovirus gene transfer mediated by alphavbeta3 and also activated other integrins, alphavbeta5, alpha5beta1, and alpha2beta1, involved in angiogenesis. Certain tumor cells exhibited high spontaneous adhesion and migration, which were attributable to a VEGF-dependent autocrine/paracrine activation of integrins. This activation was mediated by the VEGFR2 receptor and regulated via phosphatidylinositol-3-kinase, Akt, and the PTEN signaling axis. Thus, integrin activation provides a mechanism for VEGF to induce a broad spectrum of cellular responses.
Mol Cell 2000 Oct
PMID:A mechanism for modulation of cellular responses to VEGF: activation of the integrins. 1109 Jun 23

Starburst polyamidoamine dendrimers are synthetic polymers with unique structural and physical characteristics suitable for DNA gene transfer. Our previous studies demonstrated that Starburst dendrimers augment plasmid-mediated gene transfer efficiency in a nonvascularized, cardiac transplantation model. In this study, the fifth generation of ethylenediamine core dendrimer was investigated for its ability to enhance gene transfer and expression in a clinically relevant murine vascularized heart transplantation model. The plasmid pMP6A-beta-gal, encoding beta-galactosidase (beta-Gal), was incubated with dendrimers to form complexes. The complexes were perfused via the coronary arteries during donor graft harvesting, and reporter gene expression was determined by quantitative evaluation of X-Gal staining. The grafts infused with pMP6A-beta-gal/dendrimer complexes showed beta-Gal expression in myocytes from 7 to 14 days. A number of variables for transfer of the DNA/dendrimer complexes were tested, including DNA:dendrimer charge ratios, concentrations of DNA and dendrimer, preservation solutions, ischemic time, and enhancement of vascular permeability by serotonin, papaverine, and VEGF administration. The results showed that DNA/dendrimer complexes containing 20 microg of DNA and 260 microg of dendrimer (1:20 charge ratio) in a total volume of 200 microl resulted in highest gene expression in the grafts. The results also showed that prolonged incubation (cold ischemic time) to 2 h and pretreatment with serotonin further enhanced gene expression.
Mol Ther 2000 Dec
PMID:DNA/dendrimer complexes mediate gene transfer into murine cardiac transplants ex vivo. 1112 61

Tissue hypoxia has been identified as being a particularly important stimulus for triggering angiogenesis. Here we report early effects of hypoxia/reoxygenation (H/R) on the protein expression profiles and localization patterns of the VEGF and Angiopoietin-Tie systems in adult rat myocardium. Western blot as well as immunohistochemical analyses were performed on hearts obtained from rats exposed to various durations of in vivo systemic hypoxemic hypoxia followed by 24 h reoxygenation. The relative time course of protein expression in response to increasing durations of hypoxia, as indicated from our experiments, seems to suggest the involvement of the VEGF system and the Ang-Tie system in early angiogenesis. An apparent relationship between the expression profiles of Flk-1 and Ang-2 was observed. The most significant and interesting relationship which came to light was the surprisingly coincident yet opposite temporal trends between Ang-1 and Ang-2 protein levels. In the 1 h hypoxia group, there was significant induction of Ang-2 expression (31.3% compared to its baseline control) in contrast to relatively mild Ang-1 expression (23.8% compared to its baseline control). Thereafter Ang-1 displayed a progressive increase in expression, parallel to a progressive decrease in Ang-2 expression, becoming most pronounced in the 4 h hypoxia group (Ang-1, 50% and Ang-2, 12.6% compared to respective baseline control values). This suggests that despite their being antagonists at the receptor level, regulation of Ang-1 and Ang-2 protein levels in response to hypoxia runs much deeper and seems to indicate modulatory control at the transcriptional and/or translational level. Two additional groups of rats were sacrificed 7 days after 4 h hypoxia + 24 h reoxygenation, or after a 28 h period of time-matched normoxia. Left ventricular tissue sections were used to determine capillary density (CD) by using anti-CD31 immunohistochemistry and computer-assisted morphometry. CD was significantly increased in the 4 h hypoxia group compared to control (1814+/-56 vs. 1642+/-43 counts/mm2) confirming that modulation of angiogenic factors and their receptors by H/R is capable of stimulating capillary proliferation in the myocardium. Our study presents the first evidence for the Ang-Tie system's involvement in early stages of myocardial angiogenesis along with the VEGF-Flk-1-Flt-1 system. The stimulation of myocardial angiogenesis by H/R may constitute a potential basis for a possible more long-lived adaptive response to stress afforded by preconditioning stimuli.
Mol Cell Biochem 2000 Oct
PMID:Early effects of hypoxia/reoxygenation on VEGF, ang-1, ang-2 and their receptors in the rat myocardium: implications for myocardial angiogenesis. 1112 53

The aim of our study was to detect and characterize mRNA expression of VEGF isoforms VEGF(121), VEGF(145), VEGF(165), VEGF(189), and VEGF(206) in human blastocysts. We recently demonstrated VEGF mRNA expression during human preimplantation embryo development, and further information regarding the alternatively spliced mRNAs resulting in freely secreted proteins or proteins bound to cell surface heparan-sulphate proteoglycans is needed to better understand the process of angiogenesis during implantation. Human blastocysts unsuitable for transfer obtained from the IVF programme at Stanford University were examined by reverse transcription/hemi-nested polymerase chain reaction for their expression of VEGF mRNA splice variants. VEGF mRNA was expressed in 17 out of 19 (89%) blastocysts. Of the 17 blastocysts, VEGF(121) mRNA was detected in 88%, VEGF(145) mRNA in 100%, VEGF(165) mRNA in 71%, and VEGF(189) mRNA in 24% of blastocysts. There was co-expression of mRNA for VEGF(121) and VEGF(145) only in 29% blastocysts, of mRNA for VEGF(165) and VEGF(145) only in 12%, and of mRNA for VEGF(121), VEGF(145) and VEGF(165) in 59% blastocysts. VEGF(206) mRNA could not be detected. In conclusion, we demonstrated that blastocysts express the mRNAs encoding for the free VEGF proteins, enabling the implanting embryo to immediately induce angiogenesis at the implantation site.
Mol Hum Reprod 2001 Jan
PMID:Vascular endothelial growth factor (VEGF) mRNA splice variants are differentially expressed in human blastocysts. 1113 61

Valentis Inc, formerly GeneMedicine, is developing a vascular endothelial growth factor (VEGF165) non-viral gene therapy using its proprietary PINC polymer for plasmid condensation. Two physician-initiated phase II angioplasty trials are ongoing, one for treating peripheral vascular disease and one for treating coronary artery disease [281714], [347153]. In February 2000, the trials were expected to be completed in the fourth quarter of 2000 [356225]; however, in October 2000, it was reported that the trial for peripheral vascular disease would be completed in the first quarter of 2001 [385232]. In March 2000, Valentis initiated a trial incorporating Valentis's DOTMA-based cationic lipid gene delivery system and the VEGF165 gene with Eurogene's local collar-reservoir delivery device. The trial is designed to demonstrate that the VEGF165 gene, delivered locally to the outside surface of a blood vessel, will transfect and express in the smooth muscle cells of the vessel wall [360683]. In March 1999, Valentis was awarded with a Phase II SBIR grant of $686,260. The aim of grant was to advance the development of non-viral gene therapies for ischemia. Specifically, Valentis intended to select an optimal promoter to be used with the VEGF expression plasmid. Valentis also intended to evaluate the gene therapy system in a rabbit ischemia model and complete the necessary preclinical studies for submission of an IND [318137].
Curr Opin Mol Ther 2001 Feb
PMID:Technology evaluation: VEGF165 gene therapy, Valentis Inc. 1124 37

ImClone is developing IMC-IC11, an anti-angiogenesis chimeric monoclonal antibody specific vascular endothelial growth factor receptor 2 (VEGFR-2, also known Flk-1 in mice), for the potential treatment of cancer [156625]; it in phase I trials for the treatment of colorectal carcinoma [379143]. The related antibody DC-101 provided proof-of-principle that an anti-VEGF receptor antibody could strongly inhibit tumor growth and even cause tumor regression with the glioblastoma tumor cell line, GBM18 [388236]. In May 1998, the company was granted US-05747651 by the USPTO, covering antibodies against the extracellular portion of the FLK-1/KDR receptor [284054].
Curr Opin Mol Ther 2001 Aug
PMID:Technology evaluation: IMC-1C11, ImClone Systems. 1152 67


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