The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Xandra O Breakefield - One of the best experts on this subject based on the ideXlab platform.
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Correction of acid beta-galactosidase deficiency in GM1 gangliosidosis human fibroblasts by Retrovirus Vector-mediated gene transfer: higher efficiency of release and cross-correction by the murine enzyme.
Human gene therapy, 2000Co-Authors: Miguel Sena-esteves, Sara M. Camp, Xandra O Breakefield, Joseph Alroy, Edward M. KayeAbstract:Mutations in the lysosomal acid beta-galactosidase (EC 3.2.1.23) underlie two different disorders: GM1 gangliosidosis, which involves the nervous system and visceral organs to varying extents, and Morquio's syndrome type B (Morquio B disease), which is a skeletal-connective tissue disease without any CNS symptoms. This article shows that transduction of human GM1 gangliosidosis fibroblasts with Retrovirus Vectors encoding the human acid beta-galactosidase cDNA leads to complete correction of the enzymatic deficiency. The newly synthesized enzyme is correctly processed and targeted to the lysosomes in transduced cells. Cross-correction experiments using Retrovirus-modified cells as enzyme donors showed, however, that the human enzyme is transferred at low efficiencies. Experiments using a different Retrovirus Vector carrying the human cDNA confirmed this observation. Transduction of human GM1 fibroblasts and mouse NIH 3T3 cells with a Retrovirus Vector encoding the mouse beta-galactosidase cDNA resulted in high levels of enzymatic activity. Furthermore, the mouse enzyme was found to be transferred to human cells at high efficiency. Enzyme activity measurements in medium conditioned by genetically modified cells suggest that the human beta-galactosidase enzyme is less efficiently released to the extracellular space than its mouse counterpart. This study suggests that lysosomal enzymes, contrary to the generalized perception in the field of gene therapy, may differ significantly in their properties and provides insights for design of future gene therapy interventions in acid beta-galactosidase deficiency.
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single step conversion of cells to Retrovirus Vector producers with herpes simplex virus epstein barr virus hybrid amplicons
Journal of Virology, 1999Co-Authors: Miguel Senaesteves, Yoshinaga Saeki, Sara M. Camp, Antonio E Chiocca, Xandra O BreakefieldAbstract:We report here on the development and characterization of a novel herpes simplex virus type 1 (HSV-1) amplicon-based Vector system which takes advantage of the host range and retention properties of HSV–Epstein-Barr virus (EBV) hybrid amplicons to efficiently convert cells to Retrovirus Vector producer cells after single-step transduction. The Retrovirus genes gag-pol and env (GPE) and retroviral Vector sequences were modified to minimize sequence overlap and cloned into an HSV-EBV hybrid amplicon. Retrovirus expression cassettes were used to generate the HSV-EBV-Retrovirus hybrid Vectors, HERE and HERA, which code for the ecotropic and the amphotropic envelopes, respectively. Retrovirus Vector sequences encoding lacZ were cloned downstream from the GPE expression unit. Transfection of 293T/17 cells with amplicon plasmids yielded Retrovirus titers between 106 and 107 transducing units/ml, while infection of the same cells with amplicon Vectors generated maximum titers 1 order of magnitude lower. Retrovirus titers were dependent on the extent of transduction by amplicon Vectors for the same cell line, but different cell lines displayed varying capacities to produce Retrovirus Vectors even at the same transduction efficiencies. Infection of human and dog primary gliomas with this system resulted in the production of Retrovirus Vectors for more than 1 week and the long-term retention and increase in transgene activity over time in these cell populations. Although the efficiency of this system still has to be determined in vivo, many applications are foreseeable for this approach to gene delivery.
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Single-Step Conversion of Cells to Retrovirus Vector Producers with Herpes Simplex Virus–Epstein-Barr Virus Hybrid Amplicons
Journal of Virology, 1999Co-Authors: Miguel Sena-esteves, Yoshinaga Saeki, Sara M. Camp, E. Antonio Chiocca, Xandra O BreakefieldAbstract:We report here on the development and characterization of a novel herpes simplex virus type 1 (HSV-1) amplicon-based Vector system which takes advantage of the host range and retention properties of HSV–Epstein-Barr virus (EBV) hybrid amplicons to efficiently convert cells to Retrovirus Vector producer cells after single-step transduction. The Retrovirus genes gag-pol and env (GPE) and retroviral Vector sequences were modified to minimize sequence overlap and cloned into an HSV-EBV hybrid amplicon. Retrovirus expression cassettes were used to generate the HSV-EBV-Retrovirus hybrid Vectors, HERE and HERA, which code for the ecotropic and the amphotropic envelopes, respectively. Retrovirus Vector sequences encoding lacZ were cloned downstream from the GPE expression unit. Transfection of 293T/17 cells with amplicon plasmids yielded Retrovirus titers between 106 and 107 transducing units/ml, while infection of the same cells with amplicon Vectors generated maximum titers 1 order of magnitude lower. Retrovirus titers were dependent on the extent of transduction by amplicon Vectors for the same cell line, but different cell lines displayed varying capacities to produce Retrovirus Vectors even at the same transduction efficiencies. Infection of human and dog primary gliomas with this system resulted in the production of Retrovirus Vectors for more than 1 week and the long-term retention and increase in transgene activity over time in these cell populations. Although the efficiency of this system still has to be determined in vivo, many applications are foreseeable for this approach to gene delivery.
Sara M. Camp - One of the best experts on this subject based on the ideXlab platform.
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Correction of acid beta-galactosidase deficiency in GM1 gangliosidosis human fibroblasts by Retrovirus Vector-mediated gene transfer: higher efficiency of release and cross-correction by the murine enzyme.
Human gene therapy, 2000Co-Authors: Miguel Sena-esteves, Sara M. Camp, Xandra O Breakefield, Joseph Alroy, Edward M. KayeAbstract:Mutations in the lysosomal acid beta-galactosidase (EC 3.2.1.23) underlie two different disorders: GM1 gangliosidosis, which involves the nervous system and visceral organs to varying extents, and Morquio's syndrome type B (Morquio B disease), which is a skeletal-connective tissue disease without any CNS symptoms. This article shows that transduction of human GM1 gangliosidosis fibroblasts with Retrovirus Vectors encoding the human acid beta-galactosidase cDNA leads to complete correction of the enzymatic deficiency. The newly synthesized enzyme is correctly processed and targeted to the lysosomes in transduced cells. Cross-correction experiments using Retrovirus-modified cells as enzyme donors showed, however, that the human enzyme is transferred at low efficiencies. Experiments using a different Retrovirus Vector carrying the human cDNA confirmed this observation. Transduction of human GM1 fibroblasts and mouse NIH 3T3 cells with a Retrovirus Vector encoding the mouse beta-galactosidase cDNA resulted in high levels of enzymatic activity. Furthermore, the mouse enzyme was found to be transferred to human cells at high efficiency. Enzyme activity measurements in medium conditioned by genetically modified cells suggest that the human beta-galactosidase enzyme is less efficiently released to the extracellular space than its mouse counterpart. This study suggests that lysosomal enzymes, contrary to the generalized perception in the field of gene therapy, may differ significantly in their properties and provides insights for design of future gene therapy interventions in acid beta-galactosidase deficiency.
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single step conversion of cells to Retrovirus Vector producers with herpes simplex virus epstein barr virus hybrid amplicons
Journal of Virology, 1999Co-Authors: Miguel Senaesteves, Yoshinaga Saeki, Sara M. Camp, Antonio E Chiocca, Xandra O BreakefieldAbstract:We report here on the development and characterization of a novel herpes simplex virus type 1 (HSV-1) amplicon-based Vector system which takes advantage of the host range and retention properties of HSV–Epstein-Barr virus (EBV) hybrid amplicons to efficiently convert cells to Retrovirus Vector producer cells after single-step transduction. The Retrovirus genes gag-pol and env (GPE) and retroviral Vector sequences were modified to minimize sequence overlap and cloned into an HSV-EBV hybrid amplicon. Retrovirus expression cassettes were used to generate the HSV-EBV-Retrovirus hybrid Vectors, HERE and HERA, which code for the ecotropic and the amphotropic envelopes, respectively. Retrovirus Vector sequences encoding lacZ were cloned downstream from the GPE expression unit. Transfection of 293T/17 cells with amplicon plasmids yielded Retrovirus titers between 106 and 107 transducing units/ml, while infection of the same cells with amplicon Vectors generated maximum titers 1 order of magnitude lower. Retrovirus titers were dependent on the extent of transduction by amplicon Vectors for the same cell line, but different cell lines displayed varying capacities to produce Retrovirus Vectors even at the same transduction efficiencies. Infection of human and dog primary gliomas with this system resulted in the production of Retrovirus Vectors for more than 1 week and the long-term retention and increase in transgene activity over time in these cell populations. Although the efficiency of this system still has to be determined in vivo, many applications are foreseeable for this approach to gene delivery.
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Single-Step Conversion of Cells to Retrovirus Vector Producers with Herpes Simplex Virus–Epstein-Barr Virus Hybrid Amplicons
Journal of Virology, 1999Co-Authors: Miguel Sena-esteves, Yoshinaga Saeki, Sara M. Camp, E. Antonio Chiocca, Xandra O BreakefieldAbstract:We report here on the development and characterization of a novel herpes simplex virus type 1 (HSV-1) amplicon-based Vector system which takes advantage of the host range and retention properties of HSV–Epstein-Barr virus (EBV) hybrid amplicons to efficiently convert cells to Retrovirus Vector producer cells after single-step transduction. The Retrovirus genes gag-pol and env (GPE) and retroviral Vector sequences were modified to minimize sequence overlap and cloned into an HSV-EBV hybrid amplicon. Retrovirus expression cassettes were used to generate the HSV-EBV-Retrovirus hybrid Vectors, HERE and HERA, which code for the ecotropic and the amphotropic envelopes, respectively. Retrovirus Vector sequences encoding lacZ were cloned downstream from the GPE expression unit. Transfection of 293T/17 cells with amplicon plasmids yielded Retrovirus titers between 106 and 107 transducing units/ml, while infection of the same cells with amplicon Vectors generated maximum titers 1 order of magnitude lower. Retrovirus titers were dependent on the extent of transduction by amplicon Vectors for the same cell line, but different cell lines displayed varying capacities to produce Retrovirus Vectors even at the same transduction efficiencies. Infection of human and dog primary gliomas with this system resulted in the production of Retrovirus Vectors for more than 1 week and the long-term retention and increase in transgene activity over time in these cell populations. Although the efficiency of this system still has to be determined in vivo, many applications are foreseeable for this approach to gene delivery.
Miguel Sena-esteves - One of the best experts on this subject based on the ideXlab platform.
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Correction of acid beta-galactosidase deficiency in GM1 gangliosidosis human fibroblasts by Retrovirus Vector-mediated gene transfer: higher efficiency of release and cross-correction by the murine enzyme.
Human gene therapy, 2000Co-Authors: Miguel Sena-esteves, Sara M. Camp, Xandra O Breakefield, Joseph Alroy, Edward M. KayeAbstract:Mutations in the lysosomal acid beta-galactosidase (EC 3.2.1.23) underlie two different disorders: GM1 gangliosidosis, which involves the nervous system and visceral organs to varying extents, and Morquio's syndrome type B (Morquio B disease), which is a skeletal-connective tissue disease without any CNS symptoms. This article shows that transduction of human GM1 gangliosidosis fibroblasts with Retrovirus Vectors encoding the human acid beta-galactosidase cDNA leads to complete correction of the enzymatic deficiency. The newly synthesized enzyme is correctly processed and targeted to the lysosomes in transduced cells. Cross-correction experiments using Retrovirus-modified cells as enzyme donors showed, however, that the human enzyme is transferred at low efficiencies. Experiments using a different Retrovirus Vector carrying the human cDNA confirmed this observation. Transduction of human GM1 fibroblasts and mouse NIH 3T3 cells with a Retrovirus Vector encoding the mouse beta-galactosidase cDNA resulted in high levels of enzymatic activity. Furthermore, the mouse enzyme was found to be transferred to human cells at high efficiency. Enzyme activity measurements in medium conditioned by genetically modified cells suggest that the human beta-galactosidase enzyme is less efficiently released to the extracellular space than its mouse counterpart. This study suggests that lysosomal enzymes, contrary to the generalized perception in the field of gene therapy, may differ significantly in their properties and provides insights for design of future gene therapy interventions in acid beta-galactosidase deficiency.
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Single-Step Conversion of Cells to Retrovirus Vector Producers with Herpes Simplex Virus–Epstein-Barr Virus Hybrid Amplicons
Journal of Virology, 1999Co-Authors: Miguel Sena-esteves, Yoshinaga Saeki, Sara M. Camp, E. Antonio Chiocca, Xandra O BreakefieldAbstract:We report here on the development and characterization of a novel herpes simplex virus type 1 (HSV-1) amplicon-based Vector system which takes advantage of the host range and retention properties of HSV–Epstein-Barr virus (EBV) hybrid amplicons to efficiently convert cells to Retrovirus Vector producer cells after single-step transduction. The Retrovirus genes gag-pol and env (GPE) and retroviral Vector sequences were modified to minimize sequence overlap and cloned into an HSV-EBV hybrid amplicon. Retrovirus expression cassettes were used to generate the HSV-EBV-Retrovirus hybrid Vectors, HERE and HERA, which code for the ecotropic and the amphotropic envelopes, respectively. Retrovirus Vector sequences encoding lacZ were cloned downstream from the GPE expression unit. Transfection of 293T/17 cells with amplicon plasmids yielded Retrovirus titers between 106 and 107 transducing units/ml, while infection of the same cells with amplicon Vectors generated maximum titers 1 order of magnitude lower. Retrovirus titers were dependent on the extent of transduction by amplicon Vectors for the same cell line, but different cell lines displayed varying capacities to produce Retrovirus Vectors even at the same transduction efficiencies. Infection of human and dog primary gliomas with this system resulted in the production of Retrovirus Vectors for more than 1 week and the long-term retention and increase in transgene activity over time in these cell populations. Although the efficiency of this system still has to be determined in vivo, many applications are foreseeable for this approach to gene delivery.
Fu-qing Zeng - One of the best experts on this subject based on the ideXlab platform.
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Establishment of CXCR4-small interfering RNA Retrovirus Vector driven by human prostate-specific antigen promoter and its biological effects on prostate cancer in vitro and in vivo.
Journal of cancer research and clinical oncology, 2008Co-Authors: Ying Shi, Yi-fei Xing, Fu-qing ZengAbstract:CXC chemokine receptor-4 (CXCR4) is closely involved in bone metastasis of prostate cancer, and CXCR4 levels are frequently increased in prostate cancer cells and tissues. In the present study, its biological effects on prostate cancer in vitro and in vivo and feasibility to be a therapy target were investigated using a RNA interfering Retrovirus Vector targeting CXCR4 gene driven by human prostate-specific antigen promoter (pPSA). We established a pPSA-siCXCR4 Retrovirus Vector and transfected prostate cancer cell PC-3m, LNCaP and breast cancer cell MCF-7, respectively. The expression of CXCR4 mRNA and protein was detected by RT-PCR and western blot, and the ability of adhesion, migration, invasion of prostate cancer cells was assessed using Transwell chamber. A metastasizing model using BALB/cA mice with human bone tissue implantation was established too, and transfected prostate cancer cells were via caudal vein. Survival time of mice suffering bone metastatic tumor as well as the weight and volume of these tumors were recorded and analyzed. The expression of CXCR4 mRNA and protein in androgen-responsive LNCaP cells was blocked by the pPSA-siCXCR4 Vector, but it could not work in non androgen-responsive PC-3m cell and breast cancer cell MCF-7. The results of experiments in vitro also showed that the adhesion, transendothelial migration and invasive ability of transfected LNCaP cells were impaired, while there was no change in PC-3m and MCF-7 cells after transfection. pPSA-siCXCR4 represented a similar inhibitory effect in fluorescent bone metastasis model of LNCaP cells compared with PC-3m cells. These results suggest that the downstream siRNA controlled by PSA promoter in Retrovirus system can express selectively in androgen-responsive prostate cancer in vitro and in vivo, and CXCR4 plays an important role in prostate cancer metastasis. We believe that the pPSA-siCXCR4 Retrovirus Vector is a potential choice in gene therapy for androgen-responsive prostate cancer.
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establishment of cxcr4 small interfering rna Retrovirus Vector driven by human prostate specific antigen promoter and its biological effects on prostate cancer in vitro and in vivo
Journal of Cancer Research and Clinical Oncology, 2008Co-Authors: Ying Shi, Yi-fei Xing, Fu-qing ZengAbstract:Purpose CXC chemokine receptor-4 (CXCR4) is closely involved in bone metastasis of prostate cancer, and CXCR4 levels are frequently increased in prostate cancer cells and tissues. In the present study, its biological effects on prostate cancer in vitro and in vivo and feasibility to be a therapy target were investigated using a RNA interfering Retrovirus Vector targeting CXCR4 gene driven by human prostate-specific antigen promoter (pPSA).
Chih-chuan Liang - One of the best experts on this subject based on the ideXlab platform.
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knockdown of mouse adult β globin gene expression in mel cells by Retrovirus Vector mediated rna interference
Molecular Biotechnology, 2004Co-Authors: Na Zhao, Chang-mei Liu, Wen-ji Dong, De-pei Liu, Chih-chuan LiangAbstract:RNA interference (RNAi) efficiently induces sequence-specific gene silencing in mammalian cells through short interfering RNA (siRNA) of 21–23 nucleotides synthesized in vitro or expressed by DNA-based Vector. However, introduction of siRNA into mammalian cells by transfection limits the application of RNAi, especially when it is necessary to generate long-term gene silencing in vivo. Virus Vector-mediated RNAi provides an alternative to transfection. In the present study, we investigated such transduction system and showed that Retrovirus Vector-mediated RNAi can substantially down-regulate expression of mouse adult β-globin gene in MEL cells. The results suggest that Retrovirus Vector-delivered RNAi may find its use in functional genomics and in gene therapy.
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Retrovirus Vector-mediated stable gene silencing in human cell
Biochemical and biophysical research communications, 2004Co-Authors: Chang-mei Liu, Wen-ji Dong, De-pei Liu, Chih-chuan LiangAbstract:RNA interference (RNAi) is the mechanism of sequence-specific, post-transcriptional gene silencing initiated by short interfering RNAs (siRNAs) homologous to the gene being suppressed. siRNAs, which mediate sequence-specific mRNA degradation, are duplexes of about 21-23 nucleotides with 3'-overhangs synthesized in vitro or expressed by DNA-based Vector. However, these systems rely on transfection for delivery and cannot generate long-term gene silencing in vivo. This obstacle may be circumvented by recently developed Retrovirus- and lentivirus-delivered RNAi. Here, we describe a retroviral system for delivery of siRNA into cells, which can substantially down-regulate the expression of human p53 gene in human HepG2 cells. What's more, the G1 and S phases of cell cycle change dramatically in p53-down-regulated cells. These results indicate that Retrovirus Vector-delivered RNAi may be used in functional genomics and in gene therapy.
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Knockdown of mouse adult β-globin gene expression in MEL cells by Retrovirus Vector-mediated RNA interference
Molecular biotechnology, 2004Co-Authors: Na Zhao, Chang-mei Liu, Wen-ji Dong, De-pei Liu, Chih-chuan LiangAbstract:RNA interference (RNAi) efficiently induces sequence-specific gene silencing in mammalian cells through short interfering RNA (siRNA) of 21-23 nucleotides synthesized in vitro or expressed by DNA-based Vector. However, introduction of siRNA into mammalian cells by transfection limits the application of RNAi, especially when it is necessary to generate long-term gene silencing in vivo. Virus Vector-mediated RNAi provides an alternative to transfection. In the present study, we investigated such transduction system and showed that Retrovirus Vector-mediated RNAi can substantially down-regulate expression of mouse adult beta-globin gene in MEL cells. The results suggest that Retrovirus Vector-delivered RNAi may find its use in functional genomics and in gene therapy.