PT  - JOURNAL ARTICLE
AU  - Martina Anton
AU  - Constanze Wittermann
AU  - Roland Haubner
AU  - Marcus Simoes
AU  - Sybille Reder
AU  - Bryan Essien
AU  - Bettina Wagner
AU  - Julia Henke
AU  - Wolf Erhardt
AU  - Steffi Noll
AU  - Neil R. Hackett
AU  - Ronald G. Crystal
AU  - Markus Schwaiger
AU  - Bernd Gansbacher
AU  - Frank M. Bengel
TI  - Coexpression of Herpesviral Thymidine Kinase Reporter Gene and VEGF Gene for Noninvasive Monitoring of Therapeutic Gene Transfer: An In Vitro Evaluation
DP  - 2004 Oct 01
TA  - Journal of Nuclear Medicine
PG  - 1743--1746
VI  - 45
IP  - 10
4099  - http://jnm.snmjournals.org/content/45/10/1743.short
4100  - http://jnm.snmjournals.org/content/45/10/1743.full
SO  - J Nucl Med2004 Oct 01; 45
AB  - Coexpression of a reporter gene and a therapeutic gene may allow for noninvasive monitoring of cardiac gene therapy. We sought to evaluate the usefulness of an adenoviral vector expressing mutant herpesviral thymidine kinase reporter gene (HSV1-sr39tk) and vascular endothelial growth factor (VEGF) 121 in independent expression cassettes (Ad4tk). Methods: Accumulation of 14C-2′-fluoro-5-methyl-1-β-d-arabinofuranosyluracil (FIAU) and 9-(4-18F-fluoro-3-hydroxymethylbutyl)guanine (FHBG) as reporter probes, and secretion of VEGF into medium, were determined for Ad4tk-infected H9c2 rat cardiac cells in vitro. Results: In vitro tracer uptake increased with increasing vector concentration and over time. It was comparable to cells infected with adenovirus expressing only wild-type HSV1-tk (reporter probe: 14C-FIAU) or mutant HSV1-sr39tk (reporter probe: 18F-FHBG). No significant uptake was observed in cells infected with adenovirus expressing VEGF alone. With increasing vector concentration, Ad4tk-infected cells increasingly released VEGF into medium. VEGF production correlated significantly with cellular reporter probe uptake (r = 0.93; P = 0.0003). Conclusion: The usefulness of a vector coexpressing HSV1-tk and VEGF for noninvasive imaging of expression of a therapeutic transgene has been demonstrated in vitro. This approach may allow for future in vivo monitoring of cardiac angiogenesis gene therapy.