Application of a rapid, simple, and accurate adenovirus-based method to compare PET reporter gene/PET reporter probe systems.
OBJECTIVE
This study aims to use a simple, quantitative method to compare the HSV1sr39TK/(18) F-FHBG PET reporter gene/PET reporter probe (PRG/PRP) system with PRGs derived from human nucleoside kinases.


METHODS
The same adenovirus vector is used to express alternative PRGs. Equal numbers of vectors are injected intravenously into mice. After PRP imaging, quantitative hepatic PET signals are normalized for transduction by measuring hepatic viral genomes.


RESULTS
The same adenovirus vector was used to express equivalent amounts of HSV1sr39TK, mutant human thymidine kinase 2 (TK2-DM), and mutant human deoxycytidine kinase (dCK-A100VTM) in mouse liver. HSV1sr39TK expression was measured with (18) F-FHBG, TK2-DM and dCK-A100VTM with (18) F-L-FMAU. TK2-DM/(18) F-L-FMAU and HSV1sr39TK/(18) F-FHBG had equivalent sensitivities; dCK-A100VTM/(18) F-L-FMAU was twice as sensitive as HSV1sr39TK/(18) F-FHBG.


CONCLUSIONS
The human PRG/PRP sensitivities are comparable and/or better than HSV1sr39TK/(18) F-FHBG. However, for clinical use, identification of the best PRP substrate for each enzyme, characterization of probe distribution, and consequences of overexpressing nucleoside kinases must be evaluated.
Department of Biological Chemistry, David Geffen School of Medicine, UCLA, 341 Boyer Hall, 611 Charles E Young Drive, Los Angeles, CA, 90095-1570, USA.
Jose S
JS
Gil
Hidevaldo B
HB
Machado
Dean O
DO
Campbell
Melissa
M
McCracken
Caius
C
Radu
Owen N
ON
Witte
Harvey R
HR
Herschman
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D003001:Cloning, Molecular; D003842:Deoxycytidine Kinase / Q000235:genetics; D005260:Female; D015870:Gene Expression; D017930:Genes, Reporter / Q000235:genetics*; D005822:Genetic Vectors; D016679:Genome, Viral / Q000235:genetics; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000378:metabolism; D051379:Mice; D015335:Molecular Probes / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D049268:Positron-Emission Tomography / Q000379:methods*; D013997:Time Factors; D019562:Viral Load
D015335:Molecular Probes; D003842:Deoxycytidine Kinase