@article{GentschevAdelfingerJosupeitetal.2012, author = {Gentschev, Ivaylo and Adelfinger, Marion and Josupeit, Rafael and Rudolph, Stephan and Ehrig, Klaas and Donat, Ulrike and Weibel, Stephanie and Chen, Nanhai G. and Yu, Yong A. and Zhang, Qian and Heisig, Martin and Thamm, Douglas and Stritzker, Jochen and MacNeill, Amy and Szalay, Aladar A.}, title = {Preclinical Evaluation of Oncolytic Vaccinia Virus for Therapy of Canine Soft Tissue Sarcoma}, series = {PLoS One}, volume = {7}, journal = {PLoS One}, number = {5}, doi = {10.1371/journal.pone.0037239}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-129998}, year = {2012}, abstract = {Virotherapy using oncolytic vaccinia virus (VACV) strains is one promising new strategy for canine cancer therapy. In this study we describe the establishment of an in vivo model of canine soft tissue sarcoma (CSTS) using the new isolated cell line STSA-1 and the analysis of the virus-mediated oncolytic and immunological effects of two different Lister VACV LIVP1.1.1 and GLV-1h68 strains against CSTS. Cell culture data demonstrated that both tested VACV strains efficiently infected and destroyed cells of the canine soft tissue sarcoma line STSA-1. In addition, in our new canine sarcoma tumor xenograft mouse model, systemic administration of LIVP1.1.1 or GLV-1h68 viruses led to significant inhibition of tumor growth compared to control mice. Furthermore, LIVP1.1.1 mediated therapy resulted in almost complete tumor regression and resulted in long-term survival of sarcoma-bearing mice. The replication of the tested VACV strains in tumor tissues led to strong oncolytic effects accompanied by an intense intratumoral infiltration of host immune cells, mainly neutrophils. These findings suggest that the direct viral oncolysis of tumor cells and the virus-dependent activation of tumor-associated host immune cells could be crucial parts of anti-tumor mechanism in STSA-1 xenografts. In summary, the data showed that both tested vaccinia virus strains and especially LIVP1.1.1 have great potential for effective treatment of CSTS.}, language = {en} } @phdthesis{Heisig2010, author = {Heisig, Martin}, title = {Development of novel Listeria monocytogenes strains as therapeutic agents for targeted tumor therapy}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-48628}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2010}, abstract = {Despite marked progress in development and improvement of cancer therapies the rate of cancer related death remained stable over the last years. Especially in treating metastases alternative approaches supporting current therapies are required. Bacterial and viral vectors have been advanced from crude tools into highly sophisticated therapeutic agents detecting and treating neoplastic leasions. They might be potent enough to fill in this therapeutic demand. In this thesis Listeria monocytogenes was investigated as carrier for targeted bacterial cancer therapy. One part of the study focussed on modification of a functional bacterial mRNA delivery system. Genomic integration of T7 RNA polymerase driving mRNA production allowed reduction to an one-plasmid-system and thereby partially relieved the growth retardation exerted by mRNA delivery. Importantly the integration allowed metabolic attenuation of the mRNA delivery mutant potentially enabling in vivo applications. Further expansion of the bacterial RNA delivery system for transfer of shRNAs was examined. Bacterial mutants producing high amounts of RNA containing shRNA sequences were constructed, however a functional proof of gene silencing on delivery in eukaryotic cell lines was not achieved. The second part of this thesis focussed on increasing tumor colonization by Listeria monocytogenes in vivo. Coating bacteria with antibodies against receptors overexpressed on distinct tumor cell lines enabled specific bacterial internalization into these cells in vitro. Optimization of the bacterial antibody coating process resulted in an up to 104-fold increase of intracellular bacteria. Combination of this antibody-mediated targeting with the delivery of prodrug-converting enzymes showed a cytotoxic effect in cell lines treated with the corresponding prodrug. Since incubation in murine serum completely abrogated antibodymediated bacterial internalization the antibodies were covalently linked to the bacteria for application in xenografted tumor mice. Bacteria coated and crosslinked in this manner showed enhanced tumor targeting in a murine tumor model demonstrating antibodymediated bacterial tumor targeting in vivo. Independent of antibody-mediated tumor targeting the intrinsic tumor colonization of different Listeria monocytogenes mutants was examined. Listeria monocytogenes \&\#916;aroA \&\#916;inlGHE colonized murine melanoma xenografts highly efficient, reaching up to 108 CFU per gram of tumor mass 7 days post infection. Taken together the presented data shows highly promising aspects for potential bacterial application in future tumor therapies. Combination of the delivery systems with antibodymediated- and intrinsic bacterial tumor targeting might open novel dimensions utilizing Listeria monocytogenes as therapeutic vector in targeted tumor therapy.}, subject = {Krebs }, language = {en} }