Journal
GENE THERAPY
Volume 8, Issue 19, Pages 1490-1498Publisher
NATURE PUBLISHING GROUP
DOI: 10.1038/sj.gt.3301542
Keywords
reporter gene; dopamine receptor; positron emission tomography
Categories
Funding
- NCI NIH HHS [R0-1 CA84572, P50 CA86306] Funding Source: Medline
Ask authors/readers for more resources
The dopamine D2 receptor (D2R) has been used in adenoviral delivery systems and in tumor cell xenografts as an in vivo reporter gone. D2R reporter gene expression has been non-Invasively, repetitively and quantitatively imaged by positron emission tomography (PET), following systemic injection of a positron-labeled ligand (3-(2 '-[F-18]-fiuoroethyl)-spiperone, FESP) and subsequent D2R-dependent sequestration. However, dopamine binding to the D2R can modulate cyclic AMP levels. For optimal utilization of D2R as a reporter gene, it is important to uncouple ligand-binding from Gi-protein-mediated inhibition of cAMP production. Mutation of Asp80 or Ser194 produces D2Rs that still bind [H-3]spiperone in transfected cells. The D2R80A mutation completely eliminates the ability of the D2R to suppress forskolin-stimulated cAMP accumulation in response to dopamine, in cells transfected with a D2R80A expression plasmid and in cells infected with replication-defective adenovirus expressing D2R80A. The D2R194A mutation substantially reduces, but does, not completely eliminate, dopamine modulation of cAMP levels. Cultured cells infected with adenoviruses expressing D2R and D2R80A demonstrated equivalent [H-3]spiperone binding activity. Moreover, hepatic FESP sequestration is equivalent, following intravenous injection of adenoviruses expressing D2R and D2R80A. The D2R80A mutant, which can no longer modulate cAMP levels following ligand binding, has full capability as a PET reporter gene.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available