Improved Killing of Human High-Grade Glioma Cells by Combining Ionizing Radiation with Oncolytic Parvovirus H-1 Infection

Purpose. To elucidate the influence of ionizing radiation (IR) on the oncolytic activity of Parvovirus H-1 (H-1PV) in human high-grade glioma cells. Methods. Short term cultures of human high-grade gliomas were irradiated at different doses and infected with H-1PV. Cell viability was assessed by determining relative numbers of surviving cells. Replication of H-1PV was measured by RT-PCR of viral RNA, fluorescence-activated cell sorter (FACS) analysis and the synthesis of infectious virus particles. To identify a possible mechanism for radiation induced change in the oncolytic activity of H-1PV we performed cell cycle analyses. Results. Previous irradiation rendered glioma cells fully permissive to H-1PV infection. Irradiation 24 hours prior to H-1PV infection led to increased cell killing most notably in radioresistant glioma cells. Intracellular levels of NS-1, the main effector of H-1PV induced cytotoxicity, were elevated after irradiation. S-phase levels were increased one day after irradiation improving S-phase dependent viral replication and cytotoxicity. Conclusion. This study demonstrates intact susceptibility of previously irradiated glioma-cells for H-1PV induced oncolysis. The combination of ionizing radiation followed by H-1PV infection increased viral cytotoxicity, especially in radioresistant gliomas. These findings support the ongoing development of a clinical trial of H-1PV in patients with recurrent glioblastomas

Antioxidant-Induced Changes of the AP-1 Transcription Complex Are Paralleled by a Selective Suppression of Human Papillomavirus Transcription

Although E6 and E7 themselves possess intrinsic trans-activation capacity on their homologous promoters (14, 52), constitutive expression of E6 or E7 in immortalized or malignantly transformed human keratinocytes is mainly dependent on the availability of a defined set of transcription factors derived from the infected host cell. AP-1, for example, normally consisting of a heterodimer between c-Fos and c-Jun (for a review, see reference 4), seems to play a central role in transcriptional regulation of viral oncogene expression, since point mutations of the corresponding consensus sequences within the upstream regulatory region (URR) of HPV-16 or HPV-18 almost completely abolish the expression of URR-driven reporter plasmids in transient transfection assays Recent studies have shown that trans-activation and the DNA-binding affinity of AP-1 (1, 44) as well as that of other transcription factors such as NF-B (65, 78) or p53 (29) can be modulated not only via posttranslational modifications such as phosphorylation or dephosphorylation (for a review, see ref- erence 31) but also by alterations of the intracellular redox status. This can be achieved by certain cytokines, which are able to induce a prooxidant state within the cell by generating reactive oxygen intermediates (ROIs) Similar prooxidant conditions can also be generated either by exposing cells directly to hydrogen peroxide (40) or by genotoxic stress after UV irradiation (60), leading in both cases to the activation of AP-1 (74) and NF-B (44). While such intracellular redox changes are normally counterbalanced by antioxidant enzymes like Cu-Zn-superoxide dismutases (48) or oxidoreductases such as thioredoxin In a previous study, we showed that tumor necrosis factor alpha-induced transcription of a chemokine gene encoding monocyte chemoattractant protein 1 (MCP-1) could be completely abrogated when nonmalignant HPV-positive cells were incubated with PDTC prior to cytokine addition (57). Consistent with the aforementioned model of redox modulation of specific genes, detailed promoter analysis has revealed that NF-B and AP-1 are indeed the predominant transcription factors involved in the regulation of this particular chemokine Since AP-1 is also a central transcription factor for efficien

A non-controlled, single arm, open label, phase II study of intravenous and intratumoral administration of ParvOryx in patients with metastatic, inoperable pancreatic cancer: ParvOryx02 protocol

Background: Metastatic pancreatic cancer has a dismal prognosis, with a mean six-month progression-free survival of approximately 50% and a median survival of about 11 months. Despite intensive research, only slight improvements of clinical outcome could be achieved over the last decades. Hence, new and innovative therapeutic strategies are urgently required. ParvOryx is a drug product containing native parvovirus H-1 (H-1PV). Since H-1PV was shown to exert pronounced anti-neoplastic effects in pre-clinical models of pancreatic cancer, the drug appears to be a promising candidate for treatment of this malignancy. Methods: ParvOryx02 is a non-controlled, single arm, open label, dose-escalating, single center trial. In total seven patients with pancreatic cancer showing at least one hepatic metastasis are to be treated with escalating doses of ParvOryx according to the following schedule: i) 40% of the total dose infused intravenously in equal fractions on four consecutive days, ii) 60% of the total dose injected on a single occasion directly into the hepatic metastasis at varying intervals after intravenous infusions. The main eligibility criteria are: age ≥ 18 years, disease progression despite first-line chemotherapy, and at least one hepatic metastasis. Since it is the second trial within the drug development program, the study primarily explores safety and tolerability after further dose escalation of ParvOryx. The secondary objectives are related to the evaluation of certain aspects of anti-tumor activity and clinical efficacy of the drug. Discussion: This trial strongly contributes to the clinical development program of ParvOryx. The individual hazards for patients included in the current study and the environmental risks are addressed and counteracted adequately. Besides information on safety and tolerability of the treatment after further dose escalation, thorough evaluations of pharmacokinetics and intratumoral spread as well as proof-of-concept (PoC) in pancreatic cancer will be gained in the course of the trial. Trial registration: ClinicalTrials.gov-ID: NCT02653313, Registration date: Dec. 4th, 2015

Mit Killerviren gegen den Krebs

Bisher kennt man Viren nur als Krankheitserreger, die für eine große Zahl an Krankheiten wie Schnupfen, Grippe, Masern, Mumps, Pocken oder Aids verantwortlich sind. Und bei jeder neuen Grippeepidemie schreiben die Zeitungen sofort von Killerviren. Richtige Killerviren werden zurzeit aber von Dr. Karsten Geletneky von der Neurochirurgischen Universitätsklinik Heidelberg gemeinsam mit Prof. Jean Rommelaere am Deutschen Krebsforschungszentrum Heidelberg erprobt, die bei einem besonders schweren Hirntumor eingesetzt werden sollen. Auf dem Media-Server aufgenommen im Januar 2006. Dauer: 5 Minuten, 44 Sekunden

Immunotherapeutic Potential of Oncolytic H-1 Parvovirus: Hints of Glioblastoma Microenvironment Conversion towards Immunogenicity

Glioblastoma, one of the most aggressive primary brain tumors, is characterized by highly immunosuppressive microenvironment. This contributes to glioblastoma resistance to standard treatment modalities and allows tumor growth and recurrence. Several immune-targeted approaches have been recently developed and are currently under preclinical and clinical investigation. Oncolytic viruses, including the autonomous protoparvovirus H-1 (H-1PV), show great promise as novel immunotherapeutic tools. In a first phase I/IIa clinical trial (ParvOryx01), H-1PV was safe and well tolerated when locally or systemically administered to recurrent glioblastoma patients. The virus was able to cross the blood–brain (tumor) barrier after intravenous infusion. Importantly, H-1PV treatment of glioblastoma patients was associated with immunogenic changes in the tumor microenvironment. Tumor infiltration with activated cytotoxic T cells, induction of cathepsin B and inducible nitric oxide (NO) synthase (iNOS) expression in tumor-associated microglia/macrophages (TAM), and accumulation of activated TAM in cluster of differentiation (CD) 40 ligand (CD40L)-positive glioblastoma regions was detected. These are the first-in-human observations of H-1PV capacity to switch the immunosuppressed tumor microenvironment towards immunogenicity. Based on this pilot study, we present a tentative model of H-1PV-mediated modulation of glioblastoma microenvironment and propose a combinatorial therapeutic approach taking advantage of H-1PV-induced microglia/macrophage activation for further (pre)clinical testing

Therapeutic implications of the enhanced short and long-term cytotoxicity of radiation treatment followed by oncolytic parvovirus H-1 infection in high-grade glioma cells

The prognosis of malignant brain tumors remains extremely bad in spite of moderate improvements of conventional treatments. A promising alternative approach is the use of oncolytic viruses. Strategies to improve viral toxicity include the combination of oncolytic viruses with standard therapies. Parvovirus H-1 (H-1PV) is an oncolytic virus with proven toxicity in glioma cells. Recently it has been demonstrated that the combination of ionizing radiation (IR) with H-1PV showed promising results. Previously irradiated glioma cells remained fully permissive for H-1PV induced cytotoxicity supporting the use of H-1PV for recurrent gliomas, which typically arise from irradiated cell clones. When glioma cells were infected with H-1PV shortly (24 h) after IR, cell killing improved and only the combination of both treatments lead to complete long-term tumor cell killing. The latter finding raises the question whether IR in combination with H-1PV exerts an additional therapeutic effect on highly resistant glioma stem cells. A likely translation into current clinical treatment protocols is to use stereotactic radiation of non-resectable recurrent gliomas followed by intratumoral injection of H-1PV to harvest the synergistic effects of combination treatment