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David Klatzmann - One of the best experts on this subject based on the ideXlab platform.
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replicative retroviral vectors for cancer gene therapy
Cancer Gene Therapy, 2003Co-Authors: S. Solly, Stephane Trajcevski, Charlotte Frisen, Georg Holzer, Elisabeth Nelson, Beatrice Clerc, Evelyn Abordoadesida, Maria G Castro, Pedro R Lowenstein, David KlatzmannAbstract:Poor efficiency of gene transfer into cancer cells constitutes the major bottleneck of current cancer gene therapy. We reasoned that because tumors are masses of rapidly dividing cells, they would be most efficiently transduced with vector systems allowing transgene propagation. We thus designed two replicative retrovirus-derived vector systems: one inherently replicative vector, and one defective vector propagated by a helper retrovirus. In vitro, both systems achieved very efficient transgene propagation. In immunocompetent mice, replicative vectors transduced >85% tumor cells, whereas defective vectors transduced <1% under similar conditions. It is noteworthy that viral propagation could be efficiently blocked by azido-thymidine, in vitro and in vivo. In a model of established brain tumors treated with Suicide Genes, replicative retroviral vectors (RRVs) were approximately 1000 times more efficient than defective adenoviral vectors. These results demonstrate the advantage and potential of RRVs and strongly support their development for cancer gene therapy.
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Suicide Gene-Mediated Modulation of Graft-Versus-Host Disease
Leukemia & Lymphoma, 1999Co-Authors: José L. Cohen, Véronique Thomas-vaslin, Olivier Boyer, David KlatzmannAbstract:The development of Suicide Genes and progress in retroviral gene transfer to T-cells open new perspectives for the treatment of graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation (BMT) for leukemia and lymphoma. Indeed, Suicide Genes that metabolize inactive prodrugs into compounds toxic for dividing cells provide a powerful means for the pharmacogenetic control of T-cell reactivity. Here, we demonstrate the selective destruction of activated TK-transgenic T-cells in vivo and develop two new transgenic lines which should be useful for preclinical studies of Suicide gene therapy strategies for GVHD.
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phosphorylation and cytotoxicity of therapeutic nucleoside analogues a comparison of alpha and gamma herpesvirus thymidine kinase Suicide Genes
Cancer Gene Therapy, 1998Co-Authors: Christophe Cazaux, David Klatzmann, M Tiraby, Laurence Loubiere, L Haren, G TirabyAbstract:Thymidine kinase (TK) Genes from three alpha-herpesviruses (i.e., human herpes simplex type 1, varicella-zoster virus, equid herpesvirus 4) and two y-herpesviruses (i.e., Epstein-Barr virus and Saimiri herpesvirus 2) were cloned in expression vectors based on zeocin resistance by complementation of a TK-defective Escherichia coli strain. In vivo complementation of an appropriate yeast strain and in vitro enzymatic measurements demonstrated that all viral TKs possess a second phosphorylating activity corresponding to the thymidylate kinase function in contrast to the E coli TK, which is deprived of this activity. When expressed in an engineered E coli strain rendered resistant to purine and pyrimidine nucleoside analogs, the viral TKs sensitize host bacteria to 3'-azido-3'-deoxythymidine (AZT), 3'-deoxy-2',3'-didehydrothymidine (D4T), dideoxyinosine, or fluorodeoxyuridine (5-FUdR). The extent of activation of all these analogs, in this bacterial assay, was found to be greatly superior for the two gamma-virus TKs, compared to the alpha-virus TKs, including the reference Suicide gene, HSV1-TK. TK from the two gamma-Epstein-Barr and Saimiri 2 viruses were also found to be more efficient in sensitizing murine melanoma B16 tumor cells to pyrimide nucleoside analogs.
Mercedes Porosnicu - One of the best experts on this subject based on the ideXlab platform.
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abstract c185 head and neck squamous carcinoma cells are susceptible to the attenuated vesicular stomatitis virus expressing Suicide Genes
Molecular Cancer Therapeutics, 2009Co-Authors: Mercedes Porosnicu, Jingfang Liu, Douglas E LylesAbstract:Background: The predominant loco‐regional progression of Head and Neck Squamous Cell Carcinoma (HNSCC) makes it suitable for testing oncolytic viruses. Recent work from several laboratories including ours has focused on developing vesicular stomatitis virus (VSV) as a replication‐competent anticancer viral vector. Attenuated strains, such as M protein mutant VSV (M51R) are more likely to be promoted in clinical research. The major shortcoming of viral therapy is related to the large proportion of tumor cells remaining uninfected. We are addressing this limitation in two ways: the expression of the cytosine deaminase‐uracil phosphoribosyltransferase (C:U) Suicide gene by the rVSV vector, expected to produce a strong bystander effect and the exploitation of the radiosensitizing potential of the 5‐fluorouracil (5‐FU) chemo‐drug produced intratumorally, as well as of the VSV virus itself. Methods: We determined the susceptibility to oncolytic VSV in a collection of HNSCC cell lines and in patient HN primary tumor cells by measuring: 1) the level of GFP expression after infection with rVSV‐GFP and M51R‐GFP; 2) the viral production by plaque assay and 3) cell death by Trypan blue exclusion. The extent of defectiveness in interferon pathways was tested by employing pre‐treatment with IFN and INF‐blocking antibodies before the infection with the oncolytic VSV. We have generated the rVSV‐C:U and M51R‐C:U viruses and we tested our collection of HNSCC cell models to infection with these viruses in the presence and absence of 5‐fluorocytosine. SQ20B cell line is a model of radiation resistant HNSCC. Regular SQ20B and SQ20B infected with low‐dose M51R‐VSV were evaluated by clonogenic assay. Results: 1) All HNSCC cell models tested are susceptible to the infection with the rVSV but many present a degree of resistance to the attenuated M51R‐VSV. 2) Human Primary HNSCC cells are more resistant than the HNSCC cell lines to the M51R‐VSV; 3) The activation of IFN pathways is contributing to the resistance to M51R‐VSV. 4) Addition of the Suicide gene C:U to the attenuated VSV model significantly increased the oncolytic effect in vitro; 5) HNSCC cells infected with M51R‐VSV become more radiation sensitive. Conclusions: The decreased oncolytic effect of the attenuated M51R‐VSV can be overcome by the expression of Suicide Genes such as the yeast C:U fusion model. The demonstrated radiosensiting potential of the M51R‐VSV virus as well as the known radiosensitizing effect of the generated chemotherapeutic 5‐FU can be further exploited against the loco‐regional HNSCC tumors. Finally, we have important new information, both from cell lines and patient tissues, for proof‐of‐principle that cancers can down‐regulate antiviral responses. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C185.
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susceptibility of head and neck cancer to an attenuated model of the oncolytic vesicular stomatitis virus expressing Suicide Genes
Journal of Clinical Oncology, 2009Co-Authors: Mercedes Porosnicu, Jingfang Liu, Douglas S LylesAbstract:e14604 Background: The predominant loco-regional progression of head and neck squamous cell carcinoma (HNSCC) makes it suitable for testing oncolytic viruses. Recent work from several laboratories ...
Thomas Blankenstein - One of the best experts on this subject based on the ideXlab platform.
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double Suicide gene cytosine deaminase and herpes simplex virus thymidine kinase but not single gene transfer allows reliable elimination of tumor cells in vivo
Human Gene Therapy, 1998Co-Authors: Wolfgang Uckert, Thomas Kammertons, K Haack, Zhihai Qin, J Gebert, Dolores J Schendel, Thomas BlankensteinAbstract:ABSTRACT Suicide Genes such as cytosine deaminase (CD) and herpes simplex virus thymidine kinase (TK) encode products that convert nontoxic substances (prodrugs) into toxic metabolites. Suicide gen...
Axel Rethwilm - One of the best experts on this subject based on the ideXlab platform.
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Foamy virus vectors for Suicide gene therapy.
Gene Therapy, 1997Co-Authors: Ulf Nestler, Manfred Lücke, Wolfram Scheurlen, Jürgen Meixensberger, Martin Heinkelein, Axel Kretschmer, Axel RethwilmAbstract:To improve the delivery of so-called Suicide Genes into tumors, recombinant retroviruses were constructed by inserting the herpes virus type 1 (HSV-1) thymidine kinase (tk), the E. coli cytosine deaminase (cd) and polynucleoside phosphorylase (pnp), or the jellyfish gene for the green fluorescent protein (gfp) into a foamy virus (FV)-derived replication-competent vector (pFOV-7). Expression and stability of the inserted foreign gene was analyzed by immunoblot and polymerase chain reaction (PCR). The functionality of the Suicide Genes was determined by a metabolic assay on virus vector infected cells and treatment with the respective prodrugs. In terms of vector stability and effectiveness of specific cell killing a virus transducing the pnp gene (FOV-7/pnp) was superior to those using the other two Suicide Genes. FOV-7/pnp is a candidate virus for Suicide gene delivery into solid tumors.
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BRIEF COMMUNICATION Foamy virus vectors for Suicide gene therapy
1997Co-Authors: Ulf Nestler, Wolfram Scheurlen, Jürgen Meixensberger, Martin Heinkelein, Axel Kretschmer, Axel RethwilmAbstract:To improve the delivery of so-called Suicide Genes into immunoblot and polymerase chain reaction (PCR). The tumors, recombinant retroviruses were constructed by functionality of the Suicide Genes was determined by a inserting the herpes virus type 1 (HSV-1) thymidine kinase metabolic assay on virus vector infected cells and (tk), the E. coli cytosine deaminase (cd) and polynucleo- treatment with the respective prodrugs. In terms of vector side phosphorylase (pnp), or the jellyfish gene for the stability and effectiveness of specific cell killing a virus green fluorescent protein (gfp) into a foamy virus (FV)- transducing the pnp gene (FOV-7/pnp) was superior to derived replication-competent vector (pFOV-7). Expression those using the other two Suicide Genes. FOV-7/pnp is a and stability of the inserted foreign gene was analyzed by candidate virus for Suicide gene delivery into solid tumors.
Douglas E Lyles - One of the best experts on this subject based on the ideXlab platform.
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abstract c185 head and neck squamous carcinoma cells are susceptible to the attenuated vesicular stomatitis virus expressing Suicide Genes
Molecular Cancer Therapeutics, 2009Co-Authors: Mercedes Porosnicu, Jingfang Liu, Douglas E LylesAbstract:Background: The predominant loco‐regional progression of Head and Neck Squamous Cell Carcinoma (HNSCC) makes it suitable for testing oncolytic viruses. Recent work from several laboratories including ours has focused on developing vesicular stomatitis virus (VSV) as a replication‐competent anticancer viral vector. Attenuated strains, such as M protein mutant VSV (M51R) are more likely to be promoted in clinical research. The major shortcoming of viral therapy is related to the large proportion of tumor cells remaining uninfected. We are addressing this limitation in two ways: the expression of the cytosine deaminase‐uracil phosphoribosyltransferase (C:U) Suicide gene by the rVSV vector, expected to produce a strong bystander effect and the exploitation of the radiosensitizing potential of the 5‐fluorouracil (5‐FU) chemo‐drug produced intratumorally, as well as of the VSV virus itself. Methods: We determined the susceptibility to oncolytic VSV in a collection of HNSCC cell lines and in patient HN primary tumor cells by measuring: 1) the level of GFP expression after infection with rVSV‐GFP and M51R‐GFP; 2) the viral production by plaque assay and 3) cell death by Trypan blue exclusion. The extent of defectiveness in interferon pathways was tested by employing pre‐treatment with IFN and INF‐blocking antibodies before the infection with the oncolytic VSV. We have generated the rVSV‐C:U and M51R‐C:U viruses and we tested our collection of HNSCC cell models to infection with these viruses in the presence and absence of 5‐fluorocytosine. SQ20B cell line is a model of radiation resistant HNSCC. Regular SQ20B and SQ20B infected with low‐dose M51R‐VSV were evaluated by clonogenic assay. Results: 1) All HNSCC cell models tested are susceptible to the infection with the rVSV but many present a degree of resistance to the attenuated M51R‐VSV. 2) Human Primary HNSCC cells are more resistant than the HNSCC cell lines to the M51R‐VSV; 3) The activation of IFN pathways is contributing to the resistance to M51R‐VSV. 4) Addition of the Suicide gene C:U to the attenuated VSV model significantly increased the oncolytic effect in vitro; 5) HNSCC cells infected with M51R‐VSV become more radiation sensitive. Conclusions: The decreased oncolytic effect of the attenuated M51R‐VSV can be overcome by the expression of Suicide Genes such as the yeast C:U fusion model. The demonstrated radiosensiting potential of the M51R‐VSV virus as well as the known radiosensitizing effect of the generated chemotherapeutic 5‐FU can be further exploited against the loco‐regional HNSCC tumors. Finally, we have important new information, both from cell lines and patient tissues, for proof‐of‐principle that cancers can down‐regulate antiviral responses. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C185.
