Molecular-genetic PET imaging using an HSV1-tk mutant reporter gene with enhanced specificity to acycloguanosine nucleoside analogs

Imaging 2 different molecular-genetic events in a single subject by PET is essential in a variety of in vivo applications. Using herpes simplex virus-1 thymidine kinase (HSV1-tk) mutants with narrower substrate specificities in combination with wild-type HSV1-tk (wtHSV1-tk) would enable differential imaging with corresponding radiotracers, namely 2′-deoxy-2′-(18)F-fluoro-5-ethyl-1-β-d-arabinofuranosyl-uracil ((18)F-FEAU) and the acycloguanosine derivative 9-(4-(18)F-fluoro-3-[hydroxymethyl]butyl)guanine ((18)F-FHBG). In this study, we evaluated wtHSV1-tk and the A168H mutant, which has been reported to exhibit enhanced acycloguanosine substrate catalytic activity and diminished pyrimidine phosphorylating activity, as PET reporter genes.

Amer M. Najjar, Ryuichi Nishii, David S. Maxwell, Andrei Volgin, Uday Mukhopadhyay, William G. Bornmann, William Tong, Mian Alauddin, Juri G. Gelovani
March 1, 2009
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