@article{HillStritzkerScadengetal.2011,
  author    = {Hill, Philip J. and Stritzker, Jochen and Scadeng, Miriam and Geissinger, Ulrike and Haddad, Daniel and Basse-L{\"u}sebrink, Thomas C. and Gbureck, Uwe and Jakob, Peter and Szalay, Aladar A.},
  title     = {Magnetic Resonance Imaging of Tumors Colonized with Bacterial Ferritin-Expressing \(Escherichia\) \(coli\)},
  series = {PLoS ONE},
  volume    = {6},
  journal   = {PLoS ONE},
  number    = {10},
  doi       = {10.1371/journal.pone.0025409},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140920},
  pages     = {e25409},
  year      = {2011},
  abstract  = {Background: Recent studies have shown that human ferritin can be used as a reporter of gene expression for magnetic resonance imaging (MRI). Bacteria also encode three classes of ferritin-type molecules with iron accumulation properties. Methods and Findings: Here, we investigated whether these bacterial ferritins can also be used as MRI reporter genes and which of the bacterial ferritins is the most suitable reporter. Bacterial ferritins were overexpressed in probiotic E. coli Nissle 1917. Cultures of these bacteria were analyzed and those generating highest MRI contrast were further investigated in tumor bearing mice. Among members of three classes of bacterial ferritin tested, bacterioferritin showed the most promise as a reporter gene. Although all three proteins accumulated similar amounts of iron when overexpressed individually, bacterioferritin showed the highest contrast change. By site-directed mutagenesis we also show that the heme iron, a unique part of the bacterioferritin molecule, is not critical for MRI contrast change. Tumor-specific induction of bacterioferritin-expression in colonized tumors resulted in contrast changes within the bacteria-colonized tumors. Conclusions: Our data suggest that colonization and gene expression by live vectors expressing bacterioferritin can be monitored by MRI due to contrast changes.},
  language  = {en}
}
@article{HaddadChenZhangetal.2011,
  author    = {Haddad, Dana and Chen, Nanhai G. and Zhang, Qian and Chen, Chun-Hao and Yu, Yong A. and Gonzalez, Lorena and Carpenter, Susanne G. and Carson, Joshua and Au, Joyce and Mittra, Arjun and Gonen, Mithat and Zanzonico, Pat B. and Fong, Yuman and Szalay, Aladar A.},
  title     = {Insertion of the human sodium iodide symporter to facilitate deep tissue imaging does not alter oncolytic or replication capability of a novel vaccinia virus},
  series = {Journal of Translational Medicine},
  volume    = {9},
  journal   = {Journal of Translational Medicine},
  number    = {36},
  doi       = {10.1186/1479-5876-9-36},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-140847},
  pages     = {1-14},
  year      = {2011},
  abstract  = {Introduction: Oncolytic viruses show promise for treating cancer. However, to assess therapeutic efficacy and potential toxicity, a noninvasive imaging modality is needed. This study aimed to determine if insertion of the human sodium iodide symporter (hNIS) cDNA as a marker for non-invasive imaging of virotherapy alters the replication and oncolytic capability of a novel vaccinia virus, GLV-1h153. Methods: GLV-1h153 was modified from parental vaccinia virus GLV-1h68 to carry hNIS via homologous recombination. GLV-1h153 was tested against human pancreatic cancer cell line PANC-1 for replication via viral plaque assays and flow cytometry. Expression and transportation of hNIS in infected cells was evaluated using Westernblot and immunofluorescence. Intracellular uptake of radioiodide was assessed using radiouptake assays. Viral cytotoxicity and tumor regression of treated PANC-1tumor xenografts in nude mice was also determined. Finally, tumor radiouptake in xenografts was assessed via positron emission tomography (PET) utilizing carrier-free (124)I radiotracer. Results: GLV-1h153 infected, replicated within, and killed PANC-1 cells as efficiently as GLV-1h68. GLV-1h153 provided dose-dependent levels of hNIS expression in infected cells. Immunofluorescence detected transport of the protein to the cell membrane prior to cell lysis, enhancing hNIS-specific radiouptake (P < 0.001). In vivo, GLV-1h153 was as safe and effective as GLV-1h68 in regressing pancreatic cancer xenografts (P < 0.001). Finally, intratumoral injection of GLV-1h153 facilitated imaging of virus replication in tumors via (124)I-PET. Conclusion: Insertion of the hNIS gene does not hinder replication or oncolytic capability of GLV-1h153, rendering this novel virus a promising new candidate for the noninvasive imaging and tracking of oncolytic viral therapy.},
  language  = {en}
}