Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0017638 (glioma)
30,880 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transduction of the herpes simplex virus thymidine kinase (HSV-tk) into vascular endothelial cells using a replication-defective adenoviral vector (Ad.CMV-tk) to confer sensitivity to ganciclovir (GCV) was investigated. The cytotoxic sensitivity of bovine aortic endothelial cells (BAEC) to GCV following Ad.CMV-tk transduction at multiplicity of infection of 100 was ten-fold that of 9L glioma cells in vitro. Deoxyribonucleic acid fragmentation was detected in these BAEC. A co-culture experiment using BAEC transduced with Ad.CMV-tk (BAEC-tk) and 9L cells expressing beta-galactosidase (9L-Lac Z) showed about 70% tumoricidal effect under the conditions of one BAEC-tk cell in 10 9L-Lac Z cells. Tumor-bearing Fisher 344 rats, an experimental brain tumor model, received Ad.CMV-tk intratumorally at 7 days after tumor implantation, and were subsequently treated with intraperitoneal GCV (100 mg/kg). Histological examination found the vascular endothelial cells adjacent to 9L glioma tissue revealed apoptosis. These results suggest that vascular endothelial cells are an attractive target for adenoviral-mediated HSV-tk gene therapy.
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PMID:Effect of adenoviral-mediated thymidine kinase transduction and ganciclovir therapy on tumor-associated endothelial cells. 936 32

This report describes a test of the hypothesis that the oncolytic effect of genetically engineered, replication competent herpes simplex viruses (HSV) depends both on cell destruction by the virus and an immune response to the tumor cells induced in an immunocompetent animal system. The oncolytic vector was a HSV recombinant virus in which both copies of the gamma 1 34.5 gene were replaced with the murine genes encoding the cytokine interleukin-4 (IL-4) or interleukin-10 (IL-10). The hypothesis predicted that if an immune response plays a role in survival following intratumoral treatment of tumor-bearing animals with HSV, expression of IL-4 should prolong survival whereas expression of IL-10 should reduce it. The results are that (1) these cytokines can be expressed by HSV in productively infected cells both in vitro and in vivo; (2) HSV-expressing IL-4 or IL-10 genes were able to infect and destroy glioma cells in vitro; (3) intracerebral inoculation of HSV expressing either IL-4 or IL-10 into syngeneic murine glioma GL-261 cells implanted in the brains of immunocompetent C57BL/6 mice produced dramatically opposite physiologic responses. The IL-4 HSV significantly prolonged survival of tumor bearers, whereas tumor-bearing mice that received the IL-10 HSV had a median survival that was identical to that of saline treated controls; (4) immunohistochemical analyses of mouse brains at 3 and 7 days after virus inoculation showed marked accumulation of inflammatory cells composed primarily of macrophages/microglia, with various proportions of CD8+ and CD4+ T cells, but few B lymphocytes. We conclude that the cytokines expressed from genes encoded in the viral genome influence HSV therapy of tumors and this is probably due to the host immune response. Thus, cytokine expression may be an important adjunct to tumor therapy utilizing genetically engineered HSV.
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PMID:Treatment of intracranial gliomas in immunocompetent mice using herpes simplex viruses that express murine interleukins. 953 73

Human U-87 malignant glioma xenografts in mice were exposed to ionizing radiation, inoculated with a herpes simplex virus 1 mutant R3616 lacking both copies of the gamma 34.5 gene, or received both virus and radiation. Dual treatment caused a significantly greater reduction in volume or total regression of tumors than either radiation or infection alone. The significantly enhanced oncolytic effects of the combined treatment correlate with two-to five-fold enhanced replication in irradiated tumor cells than in tumors receiving virus only. In addition, in situ hybridization with viral DNA probes showed that infected tumor cells were the dominant landscape of irradiated tumors and much less apparent in the nonirradiated tumors administered this virus.
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PMID:Enhancement of replication of genetically engineered herpes simplex viruses by ionizing radiation: a new paradigm for destruction of therapeutically intractable tumors. 957 34

The retrovirus vector containing Herpes simplex virus type 1 thymidine kinase (HSVtk) gene was constructed. The vector was transfected into the packaging cell line PG13. It was shown that individual transfected cells differ in the production of recombinant retrovirus and in their susceptibility to be killed by ganciclovir. Recombinant retrovirus with a gibbon envelope was able to transduce the HSVtk gene into rat glioma cells. In vivo studies confirmed the ability of intraperitoneal ganciclovir administration to influence subcutaneous and intracerebral tumors developed after injection of C6 rat glioma cells with subsequent injection of HSVtk retrovirus producing cells.
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PMID:Treatment of rat gliomas with recombinant retrovirus harboring Herpes simplex virus thymidine kinase suicide gene. 960 5

Herpes simplex virus thymidine kinase (HSV-tk) gene therapy for brain tumors depends on ganciclovir (GCV) and its transport across the blood-brain tumor barrier (BBTB). We examined whether RMP-7, the bradykinin analog and potent BBTB permeabilizer, could enhance the efficacy of GCV treatment of brain tumors by increasing the BBTB delivery of GCV. In vitro, a significant bystander cytocidal effect of GCV was shown in mixed HSV-tk-transduced (HSV-tk+) and control vector-transduced (HSV-tk-) C6 glioma cultures. A dose-dependent cytotoxic effect of GCV on untransformed C6 cells was also shown. In vivo, rats with 100% HSV-tk+ or 100% HSV-tk- intracerebral C6 gliomas were treated for 7 days with intravenous infusions of GCV alone or with GCV and RMP-7 (2.5 microg/kg/day). The growth of HSV-tk+ and HSV-tk- gliomas decreased with increasing doses of GCV. A high dosage (100 mg of GCV/kg/day) eradicated all HSV-tk- and HSV-tk+ tumors. An intermediate dosage (5 mg of GCV/kg/day) reduced the growth of HSV-tk- gliomas by 42% if given alone, and by 88% in combination with RMP-7. A low dosage (0.5 mg of GCV/kg/day) in combination with RMP-7 enhanced the regression of HSV-tk+ gliomas by 87% compared with GCV alone. Low-dose GCV was ineffective in HSV-tk- tumors. RMP-7 increased [3H] GCV tumoral uptake by 2.6- and 1.7-fold in the tumor center and periphery, respectively. We conclude that RMP-7 could be an important adjunctive treatment for suicide gene therapy of brain tumors, while an RMP-7/GCV combination may also have a significant antitumor effect in untransfected gliomas.
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PMID:Intravenous RMP-7 increases delivery of ganciclovir into rat brain tumors and enhances the effects of herpes simplex virus thymidine kinase gene therapy. 960 10

Tumor cells transduced with retrovirus carrying the herpes simplex-1 virus thymidine kinase (HSV-tk) are capable of transforming the antiviral drug ganciclovir (GVC) into a metabolic form only toxic to dividing cells. The efficiency of this suicide gene therapy is increased by a "bystander" effect resulting not only in the death of the recipient cell, but also in the death of non modified surrounding cells. Even though the mechanism of this "bystander" effect remains to be elucidated, strong evidence suggest that the immune system plays a main role to achieve complete tumor eradication. In the present study we evaluate the efficiency of this suicide system on three different tumor models: one human melanoma, one murine melanoma, and a rat glioblastoma. Tumors were established by injection of tumor cells s.c. in nude and C57Bl/6 mice, respectively, and stereotactically into the brain of Sprague Dawley rats. Animals in the treated group were co-injected with packaging cells producing recombinant retrovirus carrying the HSV-tk gene, and followed by i.p. administration of GVC. In short term studies, we observed inhibition of tumor growth for all the tumor models evaluated (p < 0.01). In long term studies, using the C6 rat glioma line, 50% of the animals survived longer than 75 days (p < 0.0001), and were able to reject a contralateral challenges with C6 parental cells. Histological and immunohistochemical analysis showed the presence at an inflammatory infiltrate composed by T lymphocytes, macrophages and polymorphonuclear cells. These data demonstrate that suicide genes might represent an attractive form of cancer gene therapy in the treatment of brain tumors and their intracerebral dissemination.
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PMID:[Antitumor gene therapy using suicide genes]. 970 53

We have investigated the effects of thymidine kinase-mediated gene therapy in a malignant rat BT4C glioma by using 1H nuclear magnetic resonance spectroscopy in vivo. Ganciclovir has been successfully used in thymidine kinase gene therapy as treatment for various experimental malignancies. The cell damaging effect seems to be mediated by apoptosis, optimally leading to eradication of tumor tissue. In this study, we show that ganciclovir treatment of tumors transfected with the herpes simplex thymidine kinase gene causes profound changes in water, metabolites, and macromolecules observable by diffusion spectroscopy. During treatment, a 50% reduction from 0.14 +/- 0.01 x 10(-9) m2/s in the apparent diffusion coefficient of choline-containing compounds can be observed, concomitant with a 219% increase in the apparent diffusion coefficient of the rapidly diffusing water component. These changes are associated with an increase in the relative fraction of this water component from 87 to 94%. The apparent diffusion coefficients of the slowly diffusing water component and macromolecules remain unaltered. The results imply a reduction in cell size and number, a significant increase in intracellular viscosity, and a possible reduction in the hydrodynamic radii of macromolecular components, which are ascribed as biophysical signatures for apoptotic cell death.
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PMID:Quantitative 1H nuclear magnetic resonance diffusion spectroscopy of BT4C rat glioma during thymidine kinase-mediated gene therapy in vivo: identification of apoptotic response. 973 86

The influence of pre-existing anti-herpes simplex type 1 (HSV-1) immunity on HSV-1 vector-mediated gene transfer to glioma cells was analyzed in this gene marking study using intracranial D74 gliomas in syngeneic Fischer rats. The HSV-1 mutant virus used, hrR3, is defective in ribonucleotide reductase and bears the marker genes E. coli lacZ and HSV-1 thymidine kinase (HSVtk). Initial marker gene expression in tumors 12 h after direct virus injection was reduced in immunized animals to about 15% of that in nonimmunized animals. Marker gene expression in both sets stayed at initial levels for 2 days after intratumoral injection and declined markedly on day 5. Inflammatory infiltrates in the tumor were more prominent in HSV-1-immunized, as compared with nonimmunized animals, at 12 and 24 h, but appeared similar at 2-5 days after injection. By day 10, the immune reaction had subsided in immunized animals and macrophages remained only in nonimmunized animals. In conclusion, gene transfer to brain tumors using a HSV-1 vector was greatly reduced, but not completely abolished, under pre-immunization conditions. Pre-existing antibodies to HSV-1 may also serve a positive role in providing an increased margin of safety in intracranial application of HSV-1 vectors by limiting spread of the virus within the brain and to other tissues.
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PMID:Pre-existing herpes simplex virus 1 (HSV-1) immunity decreases, but does not abolish, gene transfer to experimental brain tumors by a HSV-1 vector. 974 61

Gene therapy using the herpes simplex virus thymidine kinase gene (HSV-TK) is a promising new approach for the treatment of gliomas, a tumor type with a poor prognosis. To limit the toxic effects of this procedure, it is desirable to restrict expression of the HSV-TK gene to the target cells. This can be accomplished by use of the promoter of the glial fibrillary acidic protein gene, an intermediate filament protein expressed primarily in astrocytes. A plasmid containing the HSV-TK gene, driven by the human glial fibrillary acidic protein promoter gfa2, was lipofected into glioma cell lines and into an ovarian cancer cell line. Treatment with ganciclovir showed efficient killing of glioma cells, with no effect on the ovarian cells. Thus, the gfa2 promoter is a promising candidate for directing expression of toxic genes to gliomas.
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PMID:Selective killing of glioma cell lines using an astrocyte-specific expression of the herpes simplex virus-thymidine kinase gene. 978 4

Nerve growth factor beta subunit (beta-NGF) transgene delivery and expression by herpes simplex virus type 1 (HSV-1) vectors was examined in a cell culture model of neuroprotection from hydrogen peroxide toxicity. Replication-competent (tk- K mutant background) and replication-defective (ICP4(-);tk- S mutant background) vectors were engineered to contain the murine beta-NGF cDNA under transcriptional control of either the human cytomegalovirus immediate-early gene promoter (HCMV IEp) (e.g., KHN and SHN) or the latency-active promoter 2 (LAP2) (e.g., KLN and SLN) within the viral thymidine kinase (tk) locus. Infection of rat B103 and mouse N2A neuronal cell lines, 9L rat glioma cells, and Vero cells with the KHN or SHN vectors resulted in the production of beta-NGF-specific transcripts and beta-NGF protein reaching a maximum at 3 days postinfection (p.i.). NGF protein was released into the culture media in amounts ranging from 10.83 to 352.86 ng/ml, with the highest levels being achieved in B103 cells, and was capable of inducing neurite sprouting of PC-12 cells. The same vectors produced high levels of NGF in primary dorsal root ganglion (DRG) cultures at 3 days. In contrast to HCMV IEp-mediated expression, the LAP2-NGF vectors showed robust expression in primary DRG neurons at 14 days. The neuroprotective effect of vector produced NGF was assessed by its ability to inhibit hydrogen peroxide-induced neuron toxicity in primary DRG cultures. Consistent with the kinetics of vector-mediated NGF expression, HCMV-NGF vectors were effective in abrogating the toxic effects of peroxide at 3 but not 14 days p.i. whereas LAP2-NGF vector transduction inhibited apoptosis in DRG neurons at 14 days p.i. but was ineffective at 3 days p.i. Similar kinetics of NGF expression were observed with the KHN and KLN vectors in latently infected mouse trigeminal ganglia, where high levels of beta-NGF protein expression were detected at 4 wks p.i. only from the LAP2; HCMV-NGF-driven expression peaked at 3 days but could not be detected during HSV latency at 4 weeks. Together, these results indicate that (i) NGF vector-infected cells produce and secrete mature, biologically active beta-NGF; (ii) vector-synthesized NGF was capable of blocking peroxide-induced apoptosis in primary DRG cultures; and (iii) the HCMV-IEp functioned to produce high levels of NGF for several days; but (iv) only the native LAP2 was capable of long-term expression of a therapeutic gene product in latently infected neurons in vivo.
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PMID:Herpes simplex virus type 1 vector-mediated expression of nerve growth factor protects dorsal root ganglion neurons from peroxide toxicity. 984 58


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