TY  - JOUR
A1  - Tsoneva, Desislava
A1  - Stritzker, Jochen
A1  - Bedenk, Kristina
A1  - Zhang, Qian
A1  - Cappello, Joseph
A1  - Fischer, Utz
A1  - Szalay, Aladar A.
T1  - Drug-encoded Biomarkers for Monitoring Biological Therapies
JF  - PLoS One
N2  - Blood tests are necessary, easy-to-perform and low-cost alternatives for monitoring of oncolytic virotherapy and other biological therapies in translational research. Here we assessed three candidate proteins with the potential to be used as biomarkers in biological fluids: two glucuronidases from E. coli (GusA) and Staphylococcus sp. RLH1 (GusPlus), and the luciferase from Gaussia princeps (GLuc). The three genes encoding these proteins were inserted individually into vaccinia virus GLV-1h68 genome under the control of an identical promoter. The three resulting recombinant viruses were used to infect tumor cells in cultures and human tumor xenografts in nude mice. In contrast to the actively secreted GLuc, the cytoplasmic glucuronidases GusA and GusPlus were released into the supernatants only as a result of virus-mediated oncolysis. GusPlus resulted in the most sensitive detection of enzyme activity under controlled assay conditions in samples containing as little as 1 pg/ml of GusPlus, followed by GusA (25 pg/ml) and GLuc (≥375 pg/ml). Unexpectedly, even though GusA had a lower specific activity compared to GusPlus, the substrate conversion in the serum of tumor-bearing mice injected with the GusA-encoding virus strains was substantially higher than that of GusPlus. This was attributed to a 3.2 fold and 16.2 fold longer half-life of GusA in the blood stream compared to GusPlus and GLuc respectively, thus a more sensitive monitor of virus replication than the other two enzymes. Due to the good correlation between enzymatic activity of expressed marker gene and virus titer, we conclude that the amount of the biomarker protein in the body fluid semiquantitatively represents the amount of virus in the infected tumors which was confirmed by low light imaging. We found GusA to be the most reliable biomarker for monitoring oncolytic virotherapy among the three tested markers.
KW  - mouse models
KW  - vaccinia virus
KW  - luciferase
KW  - biomarkers
KW  - cytolysis
KW  - viral replication
KW  - cell cultures
KW  - blood
Y1  - 2015
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125265
VL  - 10
IS  - 9
ER  - 
TY  - JOUR
A1  - Wang, Huiqiang
A1  - Chen, Nanhai G.
A1  - Minev, Boris R.
A1  - Zimmermann, Martina
A1  - Aguilar, Richard J.
A1  - Zhang, Qian
A1  - Sturm, Julia B.
A1  - Fend, Falko
A1  - Yu, Yong A.
A1  - Cappello, Joseph
A1  - Lauer, Ulrich M.
A1  - Szalay, Aladar A.
T1  - Optical Detection and Virotherapy of Live Metastatic Tumor Cells in Body Fluids with Vaccinia Strains
JF  - PLoS ONE
N2  - Metastatic tumor cells in body fluids are important targets for treatment, and critical surrogate markers for evaluating cancer prognosis and therapeutic response. Here we report, for the first time, that live metastatic tumor cells in blood samples from mice bearing human tumor xenografts and in blood and cerebrospinal fluid samples from patients with cancer were successfully detected using a tumor cell-specific recombinant vaccinia virus (VACV). In contrast to the FDA-approved CellSearch system, VACV detects circulating tumor cells (CTCs) in a cancer biomarker-independent manner, thus, free of any bias related to the use of antibodies, and can be potentially a universal system for detection of live CTCs of any tumor type, not limited to CTCs of epithelial origin. Furthermore, we demonstrate for the first time that VACV was effective in preventing and reducing circulating tumor cells in mice bearing human tumor xenografts. Importantly, a single intra-peritoneal delivery of VACV resulted in a dramatic decline in the number of tumor cells in the ascitic fluid from a patient with gastric cancer. Taken together, these results suggest VACV to be a useful tool for quantitative detection of live tumor cells in liquid biopsies as well as a potentially effective treatment for reducing or eliminating live tumor cells in body fluids of patients with metastatic disease.
KW  - lymph nodes
KW  - cancer treatment
KW  - metastatic tumors
KW  - breast cancer
KW  - blood
KW  - prostate cancer
KW  - ascites
KW  - mouse models
Y1  - 2013
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130059
VL  - 8
IS  - 9
ER  -