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Biomedical subjects

Claude Bagnis

Publications and source records attributed to Claude Bagnis.

11 recordsLinked to original sources
PubMed2004

Herpes simplex virus thymidine kinase-mediated suicide gene therapy for hepatocellular carcinoma using HIV-1-derived lentiviral vectors.

BACKGROUND/AIMS: Gene therapy is a promising approach for treatment of hepatocellular carcinoma (HCC). However, transduction of non-tumoral hepatocytes may lead to severe hepatitis when using suicide gene therapy approaches. The aim of our study was to evaluate the gene transfer efficiency into HCC cells and normal hepatocytes using human immunodeficiency virus (HIV)-derived lentiviral vectors in vitro and in vivo. METHODS: Lentiviral vectors encoding for the LacZ gene or the fusion gene HSV-Tk/GFP were tested in vitro in human HCC cells and human hepatocytes in primary culture and in vivo in a chemically induced rat model of HCC. RESULTS: We show that HIV-1-derived lentiviral vectors are efficient in transducing HCC cells in vitro and in vivo. No significant transduction of non-tumorous hepatocytes was observed in vivo whatever the route of administration used. Measurement of tumor growth following direct intratumoral injection of a lentiviral vector containing the HSV-Tk gene and GCV treatment showed a strong antitumoral efficacy in the absence of normal liver toxicity. CONCLUSIONS: These observations suggest that lentiviral vectors allow an antitumoral effect with low liver toxicity when using suicide gene therapy approach and could be efficient tools for HCC gene therapy.

Animals↗
PubMed2003

Comparison of murine leukemia virus, human immunodeficiency virus, and adeno-associated virus vectors for gene transfer in multiple myeloma: lentiviral vectors demonstrate a striking capacity to transduce low-proliferating primary tumor cells.

Genetic modification of primary tumor cells by gene transfer is of major interest to study the role of specific genes in the biology of a given malignancy and to modify tumor cells for therapeutic use. Multiple myeloma (MM) is a low-proliferating cancer, with often less than 1% of the cells in the S phase of the cell cycle. As primary myeloma cells are notoriously difficult to transduce, we conducted a comparison of various viral vectors, known to integrate the transgene of interest into the target genome, for their ability to stably promote the expression of an enhanced green fluorescent protein (EGFP) transgene. We compared three murine leukemia virus-based vectors, differing only in their viral envelope, a human immunodeficiency virus (HIV)-based vector pseudotyped with the vesicular stomatitis virus glycoprotein (VSV-G), and an adeno-associated virus type 2 vector. Transduction characteristics of these vectors were evaluated in human myeloma cell lines and in primary myeloma cells. Unequivocally, we observed that the VSV-G/HIV vector was the most efficient vector for transducing the cell lines and the only one able to transduce primary myeloma cells reproducibly. The mean percentage of transduced primary myeloma cells was 43.6% (range, 16.3-77.6%), with one round of infection at a low multiplicity of infection, including MM cell samples with less than 1% of cells in the S phase. A quantitative polymerase chain reaction assay demonstrated that this more efficient EGFP expression was associated with a higher GFP copy number in the targeted cell. We propose that lentiviral vectors should be used for transduction of nonproliferating primary tumor cells such as myeloma cells.

Adenoviridae↗
PubMed2003

Disruption of B-cell homeostatic control mediated by the BLV-Tax oncoprotein: association with the upregulation of Bcl-2 and signaling through NF-kappaB.

Transactivating proteins associated with complex onco-retroviruses including human T-cell leukemia virus-1 (HTLV-1) and bovine leukemia virus (BLV) mediate transformation using poorly understood mechanisms. To gain insight into the processes that govern tumor onset and progression, we have examined the impact of BLV-Tax expression on ovine B-cells, the targets of BLV in experimentally infected sheep, using B-cell clones that are dependent on CD154 and gammac-common cytokines. Tax was capable of mediating progression of B-cells from cytokine dependence to cytokine independence, indicating that the transactivator can over-ride signaling pathways typically controlled by cytokine receptor activation in B-cells. When examined in the presence of both CD154 and interleukin-4, Tax had a clear supportive role on B-cell growth, with an impact on B-cell proliferation, cell cycle phase distribution, and survival. Apoptotic B-cell death mediated by growth factor withdrawal, physical insult, and NF-kappaB inhibition was dramatically reduced in the presence of Tax. Furthermore, the expression of Tax was associated with higher Bcl-2 protein levels, providing rationale for the rescue signals mediated by the transactivator. Finally, Tax expression in B-cells led to a dramatic increase of nuclear RelB/p50 and p50/p50 NF-kappaB dimers, indicating that cellular signaling through NF-kappaB is a major contributory mechanism in the disruption of B-cell homeostasis. Although Tax is involved in aspects of pathogenesis that are unique to complex retroviruses, the viral strategies associated with this transactivating oncoprotein may have wide-ranging effects that are relevant to other B-cell malignancies.

Animals↗
PubMed2003

Gene therapy of hepatocarcinoma: a long way from the concept to the therapeutical impact.

Hepatocellular carcinoma (HCC), the most prevalent histological form of primary liver cancer is one of the most frequent cancer worldwide. This pathology still requires the development of new therapeutical approaches. Gene therapy strategies focusing on the genetic manipulation of accessory cells involved in the immune reaction against cancer cells, or on the direct transduction of tumor cells with transgenes able to "suicide" cancer cells have been largely developed for more than ten years.

Animals↗
PubMed2003

Hepatoma cell-specific ganciclovir-mediated toxicity of a lentivirally transduced HSV-TkEGFP fusion protein gene placed under the control of rat alpha-fetoprotein gene regulatory sequences.

Suicide gene therapy combining herpes simplex virus thymidine kinase gene transfer and ganciclovir administration can be envisioned as a powerful therapeutical approach in the treatment of hepatocellular carcinoma; however, safety issues regarding transgene expression in parenchyma cells have to be addressed. In this study, we constructed LATKW, a lentiviral vector expressing the HSV-TkEGFP gene placed under the control of the promoter elements that control the expression of the rat alpha-fetoprotein, and assayed its specific expression in vitro in hepatocarcinoma and nonhepatocarcinoma human cell lines, and in epidermal growth factor stimulated human primary hepatocytes. Using LATKW, a strong expression of the transgene was found in transduced hepatocarcinoma cells compared to a very low expression in nonhepatocarcinoma human cell lines, as assessed by Northern blot, RT-PCR, FACS analysis and ganciclovir-mediated toxicity assay, and no expression was found in lentivirally transduced normal human hepatocytes. Altogether, these results demonstrate the possibility to use a lentivirally transduced expression unit containing the rat alpha-fetoprotein promoter to restrict the HSV-TK-mediated induced GCV sensitivity to human hepatocarcinoma cells.

Animals↗
PubMed2003

Editorial.

Explore the source record for details and available documents.

Journal Article↗
PubMed2002

p8 is critical for tumour development induced by rasV12 mutated protein and E1A oncogene.

The p8 protein is involved in the cellular stress response of many tissues. Because p8 is overexpressed in many cancers, we investigated whether its expression was required for tumour development. Mouse embryo fibroblasts (MEFs) from p8+/+ and p8-/- animals were transformed with the pBabe-rasV12/E1A retroviral vector, which expresses both the rasV12 mutated protein and the E1A oncogene. As expected, transformed p8+/+ MEFs could form colonies in soft agar. However, transformed p8-/- MEFs could not. In addition, subcutaneous or intraperitoneal injections of transformed p8+/+ MEFs always led to tumour formation in nude mice, but, again, no tumour was observed with transformed p8-/- MEFs. However, restoring p8 expression in transformed p8-/- MEFs before injection led to tumour formation. In the tumours, p8 expression was induced during tumour development. It was concluded that p8 expression in transformed MEFs is necessary for tumour formation, suggesting that the stress-response mechanisms governed by p8 are required for tumour establishment.

Adenovirus E1A Proteins↗
PubMed2002

Transient detection of beta-galactosidase activity in hematopoietic cells, following reinjection of retrovirally marked autologous blood progenitors in patients with breast or ovarian cancer receiving high-dose chemotherapy.

OBJECTIVE: The aim of this report is to demonstrate the feasibility and safety of genetically modifying autologous human blood CD34(+) cells in vitro, with a retroviral vector that encodes a marker gene. The fate of genetically modified cells and their progeny was followed in vivo, after reinfusion in patients treated with high-dose chemotherapy for poor-prognosis breast or ovarian carcinomas. PATIENTS AND METHODS: Six patients received genetically modified autologous peripheral blood progenitors, together with unmanipulated aphereses, following high-dose chemotherapy. CD34(+) cells were immunoselected from aphereses, and retrovirally transduced by coculture with the retroviral vector producing cell line, to express a nuclear localized version of E. coli beta-galactosidase, encoded by a defective Moloney-murine leukemia virus-derived retroviral vector. Cells were reinfused to the patients after myeloablation, without prior ex vivo selection. RESULTS: Five out of six patients showed the transient presence of low numbers of beta-galactosidase(+) cells, as detected with an immunocytochemical assay, in the peripheral blood, during the first month following infusion. One patient had beta-galactosidase(+) clonogenic progenitors in her marrow at two months after transplantation, including HPP-CFC; intriguingly, this patient had the lowest percentage of X-gal(+) cells in her graft. Patients experienced side effects that are often observed after high-dose chemotherapy. CONCLUSIONS: Feasibility and safety of genetic modification of human hematopoietic stem and progenitor cells are demonstrated by this study. Ex vivo or in vivo selection is not mandatory, even in clinical situations where transduced cells have no survival advantage over wild-type cells; however, significant improvements in gene transfer technology are needed to achieve potentially useful levels of expression in such clinical situations.

Aged↗
PubMed2002

Lentiviral-mediated gene delivery in human monocyte-derived dendritic cells: optimized design and procedures for highly efficient transduction compatible with clinical constraints.

Gene delivery to dendritic cells (DCs) could represent a powerful method of inducing potent, long-lasting immunity. Although recent studies underline the intense interest in lentiviral vector-mediated monocyte-derived DC transduction, efficient gene transfer methods currently require high multiplicities of infection and are not compatible with clinical constraints. We have designed a strategy to optimize the efficiency and clinical relevance of this approach. Initially, using a third generation lentiviral vector expressing green fluorescent protein, we found that modifying the vector design, the DC precursor cell type, and the DC differentiation stage for transduction results in sustained transgene expression in 75-85% of immature DCs (transduction at a multiplicity of infection of 8). This high efficiency was reproducible among different donors irrespective of whether DCs were expanded from fresh or cryopreserved CD14(+) precursors. We then developed procedures that bypass the need for highly concentrated lentiviral preparations and the addition of polybrene to achieve efficient transduction. DCs transduced under these conditions retain their immature phenotype and immunostimulatory potential in both autologous and allogeneic settings. Furthermore, genetically modified DCs maintain their ability to respond to maturation signals and secrete bioactive IL-12, indicating that they are fully functional. Finally, the level of transgene expression is preserved in the therapeutically relevant mature DCs, demonstrating that there is neither promoter-silencing nor loss of transduced cells during maturation. The novel approach described should advance lentiviral-mediated monocyte-derived DC transduction towards a clinical reality.

DNA Primers↗
PubMed2002

Picking Some News about the Retroviral Vector World from the 9th Symposium of the European Society of Gene Therapy.

The 9th symposium of the European Society of Gene Therapy (ESGT) organized by Murat Tuncer (President of the Meeting), Bernd Gansbacher (President of the ESGT), and Meral Ozguc (Secretary of the Meeting) took place in Antalya, South Turkey, on 2-4 November 2001. Although the international political context made difficult the coming of some researchers, this symposium has drawn an interesting picture of the works in progress in Europe and in the Mediterranean area.

Journal Article↗