@phdthesis{Gnamlin2015,
  author    = {Gnamlin, Prisca},
  title     = {Use of Tumor Vasculature for Successful Treatment of Carcinomas by Oncolytic Vaccinia Virus},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-119019},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2015},
  abstract  = {Tumor-induced angiogenesis is of major interest for oncology research. Vascular endothelial growth factor (VEGF) is the most potent angiogenic factor characterized so far. VEGF blockade was shown to be sufficient for angiogenesis inhibition and subsequent tumor regression in several preclinical tumor models. Bevacizumab was the first treatment targeting specifically tumor-induced angiogenesis through VEGF blockade to be approved by the Food and Drugs Administration (FDA) for cancer treatment. However, after very promising results in preclinical evaluations, VEGF blockade did not show the expected success in patients. Some tumors became resistant to VEGF blockade. Several factors have been accounted responsible, the over-expression of other angiogenic factors, the noxious influence of VEFG blockade on normal tissues, the selection of hypoxia resistant neoplastic cells, the recruitment of hematopoietic progenitor cells and finally the transient nature of angiogenesis inhibition by VEGF blockade. The development of blocking agents against other angiogenic factors like placental growth factor (PlGF) and Angiopoietin-2 (Ang-2) allows the development of an anti-angiogenesis strategy adapted to the profile of the tumor. Oncolytic virotherapy uses the natural propensity of viruses to colonize tumors to treat cancer. The recombinant vaccinia virus GLV-1h68 was shown to infect, colonize and lyse several tumor types. Its descendant GLV-1h108, expressing an anti-VEGF antibody, was proved in previous studies to inhibit efficiently tumor induced angiogenesis. Additional VACVs expressing single chain antibodies (scAb) antibodies against PlGF and Ang-2 alone or in combination with anti VEGF scAb were designed. In this study, VACV-mediated anti-angiogenesis treatments have been evaluated in several preclinical tumor models. The efficiency of PlGF blockade, alone or in combination with VEGF, mediated by VACV has been established and confirmed. PlGF inhibition alone or with VEGF reduced tumor burden 5- and 2-folds more efficiently than the control virus, respectively. Ang-2 blockade efficiency for cancer treatment gave controversial results when tested in different laboratories. Here we demonstrated that unlike VEGF, the success of Ang-2 blockade is not only correlated to the strength of the blockade. A particular balance between Ang-2, VEGF and Ang-1 needs to be induced by the treatment to see a regression of the tumor and an improved survival. We saw that Ang-2 inhibition delayed tumor growth up to 3-folds compared to the control virus. These same viruses induced statistically significant tumor growth delays. This study unveiled the need to establish an angiogenic profile of the tumor to be treated as well as the necessity to better understand the synergic effects of VEGF and Ang-2. In addition angiogenesis inhibition by VACV-mediated PlGF and Ang-2 blockade was able to reduce the number of metastases and migrating tumor cells (even more efficiently than VEGF blockade). VACV colonization of tumor cells, in vitro, was limited by VEGF, when the use of the anti-VEGF VACV GLV-1h108 drastically improved the colonization efficiency up to 2-fold, 72 hours post-infection. These in vitro data were confirmed by in vivo analysis of tumors. Fourteen days post-treatment, the anti-VEGF virus GLV-1h108 was colonizing 78.8\% of the tumors when GLV-1h68 colonization rate was 49.6\%. These data confirmed the synergistic effect of VEGF blockade and VACV replication for tumor regression. Three of the tumor cell lines used to assess VACV-mediated angiogenesis inhibition were found, in certain conditions, to mimic either endothelial cell or pericyte functions, and participate directly to the vascular structure. The expression by these tumor cells of e-selectin, p-selectin, ICAM-1 and VCAM-1, normally expressed on activated endothelial cells, corroborates our findings. These proteins play an important role in immune cell recruitment, and there amount vary in presence of VEGF, PlGF and Ang-2, confirming the involvement of angiogenic factors in the immuno-modulatory abilities of tumors. In this study VACV-mediated angiogenesis blockade proved its potential as a therapeutic agent able to treat different tumor types and prevent resistance observed during bevacizumab treatment by acting on different factors. First, the expression of several antibodies by VACV would prevent another angiogenic factor to take over VEGF and stimulate angiogenesis. Then, the ability of VACV to infect tumor cells would prevent them to form blood vessel-like structures to sustain tumor growth, and the localized delivery of the antibody would decrease the risk of adverse effects. Next, the blockade of angiogenic factors would improve VACV replication and decrease the immune-modulatory effect of tumors. Finally the fact that angiogenesis blockade lasts until total regression of the tumor would prevent the recovery of the tumor-associated vasculature and the relapse of patients.},
  subject      = {Vaccinia-Virus},
  language  = {en}
}
@article{EhrigKilincChenetal.2013,
  author    = {Ehrig, Klaas and Kilinc, Mehmet O. and Chen, Nanhai G. and Stritzker, Jochen and Buckel, Lisa and Zhang, Qian and Szalay, Aladar A.},
  title     = {Growth inhibition of different human colorectal cancer xenografts after a single intravenous injection of oncolytic vaccinia virus GLV-1h68},
  series = {Journal of Translational Medicine},
  volume    = {11},
  journal   = {Journal of Translational Medicine},
  number    = {79},
  doi       = {10.1186/1479-5876-11-79},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129619},
  year      = {2013},
  abstract  = {Background: Despite availability of efficient treatment regimens for early stage colorectal cancer, treatment regimens for late stage colorectal cancer are generally not effective and thus need improvement. Oncolytic virotherapy using replication-competent vaccinia virus (VACV) strains is a promising new strategy for therapy of a variety of human cancers. Methods: Oncolytic efficacy of replication-competent vaccinia virus GLV-1h68 was analyzed in both, cell cultures and subcutaneous xenograft tumor models. Results: In this study we demonstrated for the first time that the replication-competent recombinant VACV GLV-1h68 efficiently infected, replicated in, and subsequently lysed various human colorectal cancer lines (Colo 205, HCT-15, HCT-116, HT-29, and SW-620) derived from patients at all four stages of disease. Additionally, in tumor xenograft models in athymic nude mice, a single injection of intravenously administered GLV-1h68 significantly inhibited tumor growth of two different human colorectal cell line tumors (Duke's type A-stage HCT-116 and Duke's type C-stage SW-620), significantly improving survival compared to untreated mice. Expression of the viral marker gene ruc-gfp allowed for real-time analysis of the virus infection in cell cultures and in mice. GLV-1h68 treatment was well-tolerated in all animals and viral replication was confined to the tumor. GLV-1h68 treatment elicited a significant up-regulation of murine immune-related antigens like IFN-γ, IP-10, MCP-1, MCP-3, MCP-5, RANTES and TNF-γ and a greater infiltration of macrophages and NK cells in tumors as compared to untreated controls. Conclusion: The anti-tumor activity observed against colorectal cancer cells in these studies was a result of direct viral oncolysis by GLV-1h68 and inflammation-mediated innate immune responses. The therapeutic effects occurred in tumors regardless of the stage of disease from which the cells were derived. Thus, the recombinant vaccinia virus GLV-1h68 has the potential to treat colorectal cancers independently of the stage of progression.},
  language  = {en}
}
@phdthesis{Cook2012,
  author    = {Cook, Vanessa Janine},
  title     = {Protection of healthy tissues from infection with systemically administered vaccinia virus strains},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-69654},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Oncolytic virotherapy using recombinant vaccinia virus strains is a promising approach for the treatment of cancer. To further improve the safety of oncolytic vaccinia viruses, the cellular microRNA machinery can be applied as the host's own security mechanism to avoid unwanted viral replication in healthy tissues. MicroRNAs are a class of small single-stranded RNAs which due to their ability to mediate post-transcriptional gene-silencing, play a crucial role in almost every regulatory process in cellular metabolism. Different cancers display unique microRNA expression patterns, showing significant up- or downregulation of endogenously expressed microRNAs. Furthermore, the behavior of cancer cells can be altered by either adding microRNAs known to inhibit cancer cell spread and proliferation or suppressing cancer promoting microRNAs (oncomirs) making microRNAs promising targets for cancer gene therapy. The cell's own RNAi machinery can also be utilized to control viral replication due to the virus dependence on the host cell replication machinery, a process controlled by microRNAs. GLV-1h68 is a replication-competent recombinant oncolytic vaccinia virus constructed and generated by Genelux Corp., San Diego, CA, USA which carries insertions of three reporter gene cassettes for detection and attenuation purposes and is currently being evaluated for cancer treatment in clinical trials. Though there are hardly any side effects found in GLV-1h68 mediated oncolytic therapy an increased tropism for replication exclusively in cancer cells is desirable. Therefore it was investigated whether or not further cancer cell specificity of a recombinant vaccinia virus strain could be obtained without compromising its oncolytic activity using microRNA interference. Let-7a is a well characterized microRNA known to be expressed in high levels in healthy tissues and strongly downregulated in most cancers. To control vaccinia virus replication rates, four copies of the mature human microRNA let-7a target sequence were cloned behind the stop codon in the 3'end of the vaccinia virus D4R gene, using a GLV-1h68 derivative, GLV-1h190, as parental strain yielding the new recombinant virus strain GLV-1h250. The D4R gene belongs to the group of early transcribed vaccinia genes and encodes an essential enzyme, uracil DNA glycosylase, which catalyzes the removal of uracil residues from double-stranded DNA. A defect in D4R prevents vaccinia virus from entering into the intermediate and late phase of replication, leading to an aborted virus replication. After expression of the microRNA target sequence from the vaccinia virus genome, the endogenously expressed microRNA-let-7a should recognize its target structure within the viral mRNA transcript, thereby binding and degrading the viral mRNA which should lead to a strong inhibition of the virus replication in healthy cells. GLV-1h250 replication rates in cancerous A549 lung adenocarcinoma cells, which show a strong down-regulation of microRNA let-7a, was comparable to the replication rates of its parental strain GLV-1h190 and the control strain GLV-1h68. In contrast, GLV-1h250 displayed a 10-fold decrease in viral replication in non-cancerous ERC cells when compared to GLV-1h190 and GLV-1h68. In A549 tumor bearing nude mice GLV-1h250 replicated exclusively in the tumorous tissue and resulted in efficient tumor regression without adverse effects leading to the conclusion that GLV-1h250 replicates preferentially in cancerous cells and tissues, which display low endogenous let-7a expression levels.},
  subject      = {Vaccinia-Virus},
  language  = {en}
}
@phdthesis{Reinboth2012,
  author    = {Reinboth, Jennifer},
  title     = {Cellular Factors Contributing to Host Cell Permissiveness in Support of Oncolytic Vaccinia Virus Replication},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85392},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {In initial experiments, the well characterized VACV strain GLV-1h68 and three wild-type LIVP isolates were utilized to analyze gene expression in a pair of autologous human melanoma cell lines (888-MEL and 1936 MEL) after infection. Microarray analyses, followed by sequential statistical approaches, characterized human genes whose transcription is affected specifically by VACV infection. In accordance with the literature, those genes were involved in broad cellular functions, such as cell death, protein synthesis and folding, as well as DNA replication, recombination, and repair. In parallel to host gene expression, viral gene expression was evaluated with help of customized VACV array platforms to get better insight over the interplay between VACV and its host. Our main focus was to compare host and viral early events, since virus genome replication occurs early after infection. We observed that viral transcripts segregated in a characteristic time-specific pattern, consistent with the three temporal expression classes of VACV genes, including a group of genes which could be classified as early-stage genes. In this work, comparison of VACV early replication and respective early gene transcription led to the identification of seven viral genes whose expression correlated strictly with replication. We considered the early expression of those seven genes to be representative for VACV replication and we therefore referred to them as viral replication indicators (VRIs). To explore the relationship between host cell transcription and viral replication, we correlated viral (VRI) and human early gene expression. Correlation analysis revealed a subset of 114 human transcripts whose early expression tightly correlated with early VRI expression and thus early viral replication. These 114 human molecules represented an involvement in broad cellular functions. We found at least six out of 114 correlates to be involved in protein ubiquitination or proteasomal function. Another molecule of interest was the serine-threonine protein kinase WNK lysine-deficient protein kinase 1 (WNK1). We discovered that WNK1 features differences on several molecular biological levels associated with permissiveness to VACV infection. In addition to that, a set of human genes was identified with possible predictive value for viral replication in an independent dataset. A further objective of this work was to explore baseline molecular biological variances associated with permissiveness which could help identifying cellular components that contribute to the formation of a permissive phenotype. Therefore, in a subsequent approach, we screened a set of 15 melanoma cell lines (15-MEL) regarding their permissiveness to GLV-1h68, evaluated by GFP expression levels, and classified the top four and lowest four cell lines into high and low permissive group, respectively. Baseline gene transcriptional data, comparing low and highly permissive group, suggest that differences between the two groups are at least in part due to variances in global cellular functions, such as cell cycle, cell growth and proliferation, as well as cell death and survival. We also observed differences in the ubiquitination pathway, which is consistent with our previous results and underlines the importance of this pathway in VACV replication and permissiveness. Moreover, baseline microRNA (miRNA) expression between low and highly permissive group was considered to provide valuable information regarding virus-host co-existence. In our data set, we identified six miRNAs that featured varying baseline expression between low and highly permissive group. Finally, copy number variations (CNVs) between low and highly permissive group were evaluated. In this study, when investigating differences in the chromosomal aberration patterns between low and highly permissive group, we observed frequent segmental amplifications within the low permissive group, whereas the same regions were mostly unchanged in the high group. Taken together, our results highlight a probable correlation between viral replication, early gene expression, and the respective host response and thus a possible involvement of human host factors in viral early replication. Furthermore, we revealed the importance of cellular baseline composition for permissiveness to VACV infection on different molecular biological levels, including mRNA expression, miRNA expression, as well as copy number variations. The characterization of human target genes that influence viral replication could help answering the question of host cell response to oncolytic virotherapy and provide important information for the development of novel recombinant vaccinia viruses with improved features to enhance replication rate and hence trigger therapeutic outcome.},
  subject      = {Vaccinia-Virus},
  language  = {en}
}
@phdthesis{Buckel2012,
  author    = {Buckel, Lisa},
  title     = {Evaluating the combination of oncolytic vaccinia virus and ionizing radiation in therapy of preclinical glioma models},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85309},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Glioblastoma multiforme (GBM) represents the most aggressive form of malignant brain tumors and remains a therapeutically challenge. Intense research in the field has lead to the testing of oncolytic viruses to improve tumor control. Currently, a variety of different oncolytic viruses are being evaluated for their ability to be used in anti-cancer therapy and a few have entered clinical trials. Vaccinia virus, is one of the viruses being studied. GLV-1h68, an oncolytic vaccinia virus engineered by Genelux Corporation, was constructed by insertion of three gene cassettes, RUC-GFP fusion, β-galactosidase and β- glucuronidase into the genome of the LIVP strain. Since focal tumor radiotherapy is a mainstay for cancer treatment, including glioma therapy, it is of clinical relevance to assess how systemically administered oncolytic vaccinia virus could be combined with targeted ionizing radiation for therapeutic gain. In this work we show how focal ionizing radiation (IR) can be combined with multiple systemically delivered oncolytic vaccinia virus strains in murine models of human U-87 glioma. After initial experiments which confirmed that ionizing radiation does not damage viral DNA or alter viral tropism, animal studies were carried out to analyze the interaction of vaccinia virus and ionizing radiation in the in vivo setting. We found that irradiation of the tumor target, prior to systemic administration of oncolytic vaccinia virus GLV-1h68, increased viral replication within the U-87 xenografts as measured by viral reporter gene expression and viral titers. Importantly, while GLV-1h68 alone had minimal effect on U-87 tumor growth delay, IR enhanced GLV-1h68 replication, which translated to increased tumor growth delay and mouse survival in subcutaneous and orthotopic U-87 glioma murine models compared to monotherapy with IR or GLV-1h68. The ability of IR to enhance vaccinia replication was not restricted to the multi-mutated GLV-1h68, but was also seen with the less attenuated oncolytic vaccinia, LIVP 1.1.1. We have demonstrated that in animals treated with combination of ionizing radiation and LIVP 1.1.1 a strong pro-inflammatory tissue response was induced. When IR was given in a more clinically relevant fractionated scheme, we found oncolytic vaccinia virus replication also increased. This indicates that vaccinia virus could be incorporated into either larger hypo-fraction or more conventionally fractionated radiotherapy schemes. The ability of focal IR to mediate selective replication of systemically injected oncolytic vaccinia was demonstrated in a bilateral glioma model. In mice with bilateral U-87 tumors in both hindlimbs, systemically administered oncolytic vaccinia replicated preferentially in the focally irradiated tumor compared to the shielded non- irradiated tumor in the same mouse We demonstrated that tumor control could be further improved when fractionated focal ionizing radiation was combined with a vaccinia virus caring an anti-angiogenic payload targeting vascular endothelial growth factor (VEGF). Our studies showed that following ionizing radiation expression of VEGF is upregulated in U-87 glioma cells in culture. We further showed a concentration dependent increase in radioresistance of human endothelial cells in presence of VEGF. Interestingly, we found effects of vascular endothelial growth factor on endothelial cells were reversible by adding purified GLAF-1 to the cells. GLAF-1 is a single- chain antibody targeting human and murine VEGF and is expressed by oncolytic vaccinia virus GLV-109. In U-87 glioma xenograft murine models the combination of fractionated ionizing radiation with GLV-1h164, a vaccinia virus also targeting VEGF, resulted in the best volumetric tumor response and a drastic decrease in vascular endothelial growth factor. Histological analysis of embedded tumor sections 14 days after viral administration confirmed that blocking VEGF translated into a decrease in vessel number to 30\% of vessel number found in control tumors in animals treated with GLV-164 and fractionated IR which was lower than for all other treatment groups. Our experiments with GLV-1h164 and fractionated radiotherapy have shown that in addition to ionizing radiation and viral induced tumor cell destruction we were able to effectively target the tumor vasculature. This was achieved by enhanced viral replication translating in increased levels of GLAF-2 disrupting tumor vessels as well as the radiosensitization of tumor vasculature to IR by blocking VEGF. Our preclinical results have important clinical implications of how focal radiotherapy can be combined with systemic oncolytic viral administration for highly aggressive, locally advanced tumors with the potential, by using a vaccinia virus targeting human vascular endothelial growth factor, to further increase tumor radiation sensitivity by engaging the vascular component in addition to cancer cells.},
  subject      = {Gliom},
  language  = {en}
}
@phdthesis{Ehrig2012,
  author    = {Ehrig, Klaas},
  title     = {Effects of stem cell transcription factor-expressing vaccinia viruses in oncolytic virotherapy},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-85139},
  school      = {Universit{\"a}t W{\"u}rzburg},
  year      = {2012},
  abstract  = {Krebserkrankungen bleiben auch im Jahr 2012 die zweith{\"a}uftigste Todesursache in der industralisierten Welt. Zus{\"a}tzlich hat die Etablierung der Krebsstammzell-Hypothese grunds{\"a}tzliche Auswirkungen auf die Erfolgsaussichten konventioneller Krebstherapie, wie Chemotherapie oder Strahlentherapie. Deswegen ist es von gr{\"o}βter Notwendigkeit, dass neue Ans{\"a}tze zur Krebstherapie entwickelt werden, die den Ausgang der Behandlung verbessern und zu weniger Nebenwirkungen f{\"u}hren. Diverse vorklinische Studien haben gezeigt, dass die onkolytische Virotherapie mit Vaccinia-Viren ein potentes und gut tolerierbares neues Werkzeug in der Krebstherapie darstellt. Die Effizienz des Vaccinia-Virus als Therapeutikum allein oder in Kombination mit Strahlen- oder Chemotherapie wird aktuell in mehreren klinischen Studien der Phasen I \& II getestet. Krebsstammzellen und Stammzellen teilen eine Vielzahl von Eigenschaften, wie die F{\"a}higkeit zur Selbst-Erneuerung und Pluripotenz, Stilllegung der Zellproliferation, Resistenz gegen Medikamente oder Bestrahlung, die Expression von diversen Zelloberfl{\"a}chen-molek{\"u}len, die Aktivierung und Hemmung spezifischer Signaltransduktionswege oder die Expression von Stammzell-spezifischen Genen. In dieser Arbeit wurden zwei neue rekombinante Vaccinia-Viren entwickelt, welche die Stammzell-Transkriptionsfaktoren Nanog (GLV-1h205) und Oct4 (GLV-1h208) exprimieren, um tiefere Einblicke in die Rolle dieser Masterregulatoren in der Entstehung von Krebs und ihrem Einfluss auf die onkolytische Virotherapie zu gewinnen. Das Replikationspotential beider Virusst{\"a}mme in menschlichen A549-Zellen und PC-3-Zellen wurde anhand von Replikations-Assays bestimmt. Die Expression der Virus-spezifischen Markergene Ruc-GFP und beta-Galaktosidase, wie auch die Expression der Transkriptionsfaktoren Nanog und Oct4 wurde mit Hilfe von RT-PCR, SDS-PAGE und Western blotting, sowie immunozytochemischen Experimenten nachgewiesen. Des Weiteren wurde der Einfluss einer GLV-1h205-Infektion von A549-Zellen auf den Zellzyklus untersucht. Zudem wurde die Bedeutung der Virus-vermittelten Transkriptionsfaktor-Expression auf die Behandlung von subkutanen A549-Tumoren in einem Xenograft-Modell untersucht. Zur Untersuchung, ob die beobachteten Vorteile in der Behandlung von Lungenadenokarzinomen in M{\"a}usen mit GLV-1h205 Promoter- oder Transkriptionsfaktor-abh{\"a}ngig sind, wurde ein Kontroll-Virus (GLV-1h321) hergestellt, dass f{\"u}r eine unfunktionale Nanog-Mutante codiert. Mittels SDS-PAGE und Western blotting sowie Immunozytochemie wurde die Transgen-Expression analysiert. Ein weitere Aspekt dieser Arbeit war die Fragestellung, ob sich das onkolyische Vaccinia-Virus GLV-1h68 eignet, als neues und weniger invasives Therapeutikum effizient Darmkrebszellen zu infizieren um sich in ihnen zu replizieren und diese anschlieβend zu lysieren. Ein derartiger Therapieansatz w{\"u}rde besonders im Hinblick auf sp{\"a}t diagnostizierten, metastasierenden Darmkrebs eine interessante Behandlungsalternative darstellen. Virale Markergen-expression wurde anhand von Fluoreszenzmikroskopie und FACS-Analyse untersucht. Desweiteren wurde gezeigt, dass die einmalige Administration von GLV-1h68 in mindestens zwei verschiedenen Darmkrebszelllinien zu einer signifikanten Inhibierung des Tumorwachstums in vivo und zu signifikant verbessertem {\"U}berleben f{\"u}hrt. Der Transkriptionsfaktor Klf4 wird zwar stark in ruhenden, ausdifferenzierten Zellen des Darmepithels exprimiert, ist hingegen bei Darmkrebs generell dramatisch herabreguliert. Die Expression von Klf4 f{\"u}hrt zu einem Stop der Zellproliferation und inhibiert die Aktivit{\"a}t des Wnt-Signalweges, indem es im Zellkern an die Transaktivierungsdom{\"a}ne von beta-Catenin bindet. Um die Behandlung von Darmkrebs mit Hilfe onkolytischer Virotherapie weiter zu verbessern, wurden verschiedene Vaccinia-Viren (GLV-1h290-292) erzeugt, die durch verschiedene Promoterst{\"a}rken die Expression unterschiedlicher Mengen an Tumorsuppressor Klf4 vermitteln. Die anf{\"a}ngliche Charakterisierung der drei Virusst{\"a}mme mittels Replikations-Assay, Zytotoxizit{\"a}tstudien, SDS-PAGE und Western blotting, Immunozytochemie sowie die Analyse der Proteinfunktion mit Hilfe von qPCR- und ELISA-Analysen zur Bestimmung von zellul{\"a}rem beta-Catenin, zeigten eine Promoter-abh{\"a}ngige Expression und Wirkung von Klf4. F{\"u}r weitere Analysen wurde das Virus GLV-1h291 gew{\"a}hlt, welches nach Infektion die gr{\"o}βte Menge an Klf4 produziert und zus{\"a}tzlich durch die C-terminale Fusion einer TAT Transduktionsdom{\"a}ne Membran-g{\"a}ngig gemacht (GLV-1h391). Die erhaltenen Befunde machen das Klf4-TAT-kodierende Vaccinia-Virus GLV-1h391 zu einem vielversprechenden Kandidaten f{\"u}r eine Behandlung von Darmkrebs beim Menschen.},
  subject      = {Lungenkrebs},
  language  = {en}
}
@article{ChenYuZhangetal.2011,
  author    = {Chen, Nanhai G. and Yu, Yong A. and Zhang, Qian and Szalay, Aladar A.},
  title     = {Replication efficiency of oncolytic vaccinia virus in cell cultures prognosticates the virulence and antitumor efficacy in mice},
  series = {Journal of Translational Medicine},
  volume    = {9},
  journal   = {Journal of Translational Medicine},
  number    = {164},
  doi       = {10.1186/1479-5876-9-164},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-142268},
  pages     = {1-11},
  year      = {2011},
  abstract  = {Background: We have shown that insertion of the three vaccinia virus (VACV) promoter-driven foreign gene expression cassettes encoding Renilla luciferase-Aequorea GFP fusion protein, beta-galactosidase, and beta-glucuronidase into the F14.5L, J2R, and A56R loci of the VACV LIVP genome, respectively, results in a highly attenuated mutant strain GLV 1h68. This strain shows tumor specific replication and is capable of eradicating tumors with little or no virulence in mice. This study aimed to distinguish the contribution of added VACV promoter-driven transcriptional units as inserts from the effects of insertional inactivation of three viral genes, and to determine the correlation between replication efficiency of oncolytic vaccinia virus in cell cultures and the virulence and antitumor efficacy in mice Methods: A series of recombinant VACV strains was generated by replacing one, two, or all three of the expression cassettes in GLV 1h68 with short non coding DNA sequences. The replication efficiency and tumor cell killing capacity of these newly generated VACV strains were compared with those of the parent virus GLV-1h68 in cell cultures. The virus replication efficiency in tumors and antitumor efficacy as well as the virulence were evaluated in nu/nu (nude) mice bearing human breast tumor xenografts. Results: we found that virus replication efficiency increased with removal of each of the expression cassettes. The increase in virus replication efficiency was proportionate to the strength of removed VACV promoters linked to foreign genes. The replication efficiency of the new VACV strains paralleled their cytotoxicity in cell cultures. The increased replication efficiency in tumor xenografts resulted in enhanced antitumor efficacy in nude mice. Similarly, the enhanced virus replication efficiency was indicative of increased virulence in nude mice. Conclusions: These data demonstrated that insertion of VACV promoter-driven transcriptional units into the viral genome for the purpose of insertional mutagenesis did modulate the efficiency of virus replication together with antitumor efficacy as well as virulence. Replication efficiency of oncolytic VACV in cell cultures can predict the virulence and therapeutic efficacy in nude mice. These findings may be essential for rational design of safe and potent VACV strains for vaccination and virotherapy of cancer in humans and animals.},
  language  = {en}
}