Inhibition of glioma cells in vitro and in vivo using a recombinant adenoviral vector containing an astrocyte-specific promoter (original) (raw)
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Cancer research, 1998
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.
Cancer Gene Therapy, 2000
Herpes simplex virus thymidine kinase (HSV-tk) gene transfer and ganciclovir (GCV) administration have been suggested for the treatment of malignant gliomas. To understand tissue responses and possible ways to improve the treatment effect, we studied tumor growth, tissue reactions, and survival time after HSV-tk/GCV treatment in a syngeneic BT4C rat glioma model by mixing various ratios of stably transfected HSV-tk-expressing BT4C-tk glioma cells with wild-type BT4C glioma cells (percentage of BT4C-tk cells: 0%, 1%, 10%, 30%, 50%, and 100%), followed by injection into BDIX rat brains (n ϭ 79). With the exception of some animals with end-stage tumors, very little astroglia or microglia reactivity was detected in the wild-type tumors as analyzed by immunocytochemistry using glial fibrillary acid protein (GFAP)-, vimentin-, human histocompatibility leukocyte antigen-DR-, OX-42-, and CD68-specific monoclonal antibodies. After 14 days of GCV treatment, tumors induced with Ն10% BT4C-tk cells showed a significant reduction in tumor size (P Ͻ .05) and prolonged survival time (P Ͻ .01). Astrogliosis, as indicated by a strong GFAP and vimentin immunoreactivity, was seen in the tumor scar area. GFAP and vimentin reactivity was already present after the GCV treatment in tumors induced with 1% BT4C-tk cells. Much less human histocompatibility leukocyte antigen-DR-positive microglia was seen in the treated animals, indicating low microglia reactivity and immunoactivation against the tumor. However, GCV-treated tumors were positive for apoptosis, indicating that apoptosis is an important mechanism for cell death in the BT4C-tk glioma model. Our results suggest that Ն10% transfection efficiency is required for a successful reduction in BT4C glioma tumor size with HSV-tk/GCV treatment in vivo. Tissue reactions after 14 days of GCV treatment are characterized by astrogliosis and apoptosis, whereas microglia response and immunoactivation of the brain cells appear to play a minor role. Stimulation of the microglia response by gene transfer or other means might improve the efficacy of the HSV-tk/GCV treatment in vivo. Cancer Gene Therapy (2000) 7, 413-421
Cancer Gene Therapy, 2000
Transfer of the herpes simplex virus thymidine kinase (HSVtk) gene, followed by administration of ganciclovir (GCV), generates the "bystander effect," in which HSVtk-negative wild-type cells are killed by GCV, as are HSVtk-expressing cells. Our previous study demonstrated that intracranial 9L gliomas could be efficiently treated due to this bystander effect by injecting the 9L glioma cells transduced with the HSVtk gene in the vicinity of the preimplanted wild-type 9L glioma and then administering GCV. For a possible clinical application of the bystander effect-mediated cell killing, we tested HSVtk gene-transduced allogeneic C6 glioma cells (C6tk) instead of syngeneic 9L glioma cells transduced with the HSVtk gene. Fisher rats were implanted intracranially with wild-type 9L glioma cells, subsequently injected with C6tk cells at the same brain coordinate, and thereafter treated with GCV or saline. When the rats were treated with GCV, a significant retardation of tumor growth was observed by serial magnetic resonance imaging, although this growth retardation was less prominent than that observed with 9L glioma cells transduced with the HSVtk gene; consequently, survival was prolonged (P Ͻ .01). Tumors that received C6tk cells contained almost no HSVtk-positive cells after treatment with GCV. Rejection of allogeneic tumor cells, although possibly incomplete in the brain, can also contribute to the safety of this therapeutic strategy. Cancer Gene Therapy (2000) 7, 947-953
Journal of Neuro-oncology, 2004
Object: In mouse models of prostate and breast cancer therapeutic effects are enhanced when adenoviral HSV TK gene therapy is combined with ionizing radiation. In the present study, we adopted this approach for the treatment of human glioblastoma xenografts in an athymic mouse model and assessed treatment results as well as toxic side effects. Methods: About 72 nude mice received intracerebral inoculations of 2 × 105 U87ΔEGFR cells. On day 7 after tumor implantation the study population was randomized into six treatment arms: (1) intratumoral buffer inoculation on day 7, (2) intratumoral adenoviral vector injection (2 × 109 vp) on day 7, (3) single dose radiation (2.1 Gy) on day 9, (4) adenoviral injection + radiation, (5) adenoviral injection + ganciclovir (GCV) (20 ug/g twice daily from day 8 to 17), (6) adenoviral injection + GCV + radiation. On day 21 half of the animals were sacrificed for histological evaluation of the brain tumors, the other half was assessed for survival. Results: This study showed significantly prolonged median survival time of 5 days for the GCV treated groups. The addition of radiation decreased the frequency of neurological symptoms and delayed the onset of deficits without altering the expression of thymidine kinase in the tumor cells. Conclusions: We conclude that adenoviral HSV TK gene therapy in combination with adjuvant radiotherapy does not generate increased toxic side effects in glioblastoma treatment. The prolonged survival time of animals receiving gene therapy and the reduced occurrence of neurological symptoms in irradiated mice constitute promising features of the combined treatment.
Treatment of rat gliosarcoma brain tumors by HSV-based multigene therapy combined with radiosurgery
Molecular Therapy, 2003
Our laboratory has employed replication-defective herpes simplex virus type 1 gene transfer vectors for treatment of animal models of human malignant glioblastoma. The base vectors were defective for the immediate early (IE) genes ICP4, ICP27, and ICP22 but expressed the IE gene ICP0, which can arrest tumor cell division, and an IE thymidine kinase (␣-tk) gene construct that mediates suicide gene therapy (SGT) in the presence of ganciclovir (GCV). Previously, we reported that SGT using ICP0/␣-tk vectors in nude mouse models of glioblastoma was improved by coexpression of the gap-junction-forming protein connexin43 (Cx43) or human tumor necrosis factor ␣ (TNF␣). We also showed that further gains in therapeutic outcome could be achieved by combining TNF␣-enhanced SGT with gamma-knife radiosurgery (GKR). To expand these observations, we have first repeated these studies in immunocompetent rats with brain tumors derived from implanted 9L gliosarcoma cells and second compared the most efficient vector from this study with a new recombinant vector, NUREL-C2, which expressed both TNF␣ and Cx43 along with ICP0 and ␣-tk. Results from the first part indicated that our ICP0/␣-tk/TNF␣ vector in combination with GKR provides an effective therapy although this treatment was not statistically better than GKR combined with the ICP0/␣-tk/Cx43 vector. Our observations in the second part suggested that NUREL-C2 may be more effective than the ICP0/␣-tk/TNF␣ vector in combination treatments with GCV (P ؍ 0.08) or GCV plus GKR (P ؍ 0.10). GKR significantly enhanced the efficacy of NUREL-C2/GCV treatment (P ؍ 0.02) as well as other virus/GCV treatments (P < 0.05). Conversely, the efficacy of GKR was significantly improved by both the ICP0/␣-tk/TNF␣ vector and NUREL-C2 in combination with GCV (P ؍ 0.02 and P < 0.01, respectively). Together these results indicate that NUREL-C2 may be an attractive candidate for Phase I gene-therapy safety studies in patients with recurrent malignant glioblastoma.
Genetically engineered HSV in the treatment of glioma: a review
Reviews in Medical Virology, 2000
Central nervous system malignancies, particularly glioblastoma multiforme, pose signi®cant problems for the development of novel therapeutics. In the absence of advances with standard surgical and chemotherapeutic approaches, the utilisation of genetically engineered viruses, both as direct oncolytic agents as well as for the delivery of foreign proteins, represents a signi®cant advance in the experimental approach to management of patients with these incurable tumours. Among other viruses, HSV offers an opportunity to directly in¯uence the replication of tumour cells within the central nervous system. Because of its propensity to replicate in neuronal tissue as well as its large coding capacity, it provides an experimental model for the development of novel therapeutics. The status of these experimental approaches will be summarised in this review.
Cancer Gene Therapy, 2001
Due to minimal treatment success with surgery, radiotherapy, and chemotherapy, the aim of this study was to test the therapeutic potential of gene therapy for the treatment of glioblastoma multiforme (GBM). We have quantitatively analyzed two gene therapy approaches using short-term human glioma cell cultures derived from surgical biopsies (designated IN859, IN1612, IN2045, IN1760, and IN1265) and compared the results of gene therapy with the chemosensitivity of the same cells. All of the glioma cell cultures tested were susceptible to recombinant adenovirus (RAd)-mediated infection. Expression of herpes simplex virus type 1thymidine kinase (RAd128) , followed by ganciclovir treatment, induced apoptosis in all of the glioma cell cultures studied, including three that are resistant to the chemotherapeutic drug 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU). Expression of murine Fas ligand (RAdhCMV-mFasL) also induced cell death in four of the five cell cultures studied. One cell culture that was resistant to CCNU was also resistant to apoptosis induced by mFasL expression. These results suggest that sensitivity to chemotherapeutic agents does not necessarily correlate with the sensitivity to gene therapy treatments. RAds expressing therapeutic gene products in human glioma cell cultures are able to induce apoptosis even in some cells that are resistant to a commonly used chemotherapeutic agent. Therefore, RAd-mediated gene transfer could be a good candidate to further develop gene therapy for the treatment of GBM.
Human Gene Therapy, 1997
The growth of U-87 or C6 gliomas co-implanted in nude mice with retroviral producer cells (VPC) expressmg the herpes simplex virus-thymidine kinase (HSV-tk) gene is only partially impaired by treatment with ganciclovir (GCV). The effect of GCV is even less evident when C6 and VPC are co-implanted into the rat brain. Furthermore, tumors from C6 cells carrying the HSV-tk gene are not eradicated by GCV, although they remain sensitive to GCV when replated in vitro. These limits of the HSV-tk/GCV system in glioma gene therapy may be due to insufficient gene transfer and/or insufficient delivery of GCV to glioma cells. Combination of HSV-tk and one or more cytokines may improve the antitumor efficacy. Among cytokines, interleukin-4 (IL-4) has already been shown to be active against gliomas. In nude mice, GCV treatment inhibited tumor growth more effectively after co-injection of C6 cells with a mixture of VPC transducing IL-4 and HSVtk genes than after co-injection with either IL-4 or HSV-tk VPC only. In immunocompetent Sprague-Dawley rats, co-injection of IL-4 VPC and C6 cells was also effective in inhibiting the growth of C6 brain tumors, 38% of the animals surviving for at least 2 months. Furthermore, increased and prolonged antitumor efficacy was obtained by transducing both IL-4 and HSV-tk genes.