Repetitive, non-invasive imaging of the dopamine D2 receptor as a reporter gene in living animals

• Published in: Gene therapy Vol. 6; no. 5; pp. 785 - 791
• Main Authors: MACLAREN, D. C, GAMBHIR, S. S, HERSCHMAN, H. R, SATYAMURTHY, N, BARRIO, J. R, SHARFSTEIN, S, TOYOKUNI, T, WU, L, BERK, A. J, CHERRY, S. R, PHELPS, M. E
• Format: Journal Article
• Language: English
• Published: Basingstoke Nature Publishing Group 01.05.1999
• Subjects: Acetyltransferase; Adenoviridae - genetics; Animals; Biological and medical sciences; Biopsy; Biotechnology; Chloramphenicol; Dopamine; Dopamine Antagonists; Dopamine D2 receptors; Expression vectors; Fluorescent Dyes; Fundamental and applied biological sciences. Psychology; Gene Expression; Gene therapy; Gene transfer; Genes, Reporter; Genetic Vectors - administration & dosage; Green fluorescent protein; Health. Pharmaceutical industry; Industrial applications and implications. Economical aspects; Liver; Liver - diagnostic imaging; Liver - metabolism; Male; Mice; Mice, Nude; Mice, Transgenic; Neoplasms, Experimental - diagnostic imaging; Neoplasms, Experimental - metabolism; Positron emission tomography; Radioligand Assay; Receptors, Dopamine D2 - genetics; Reporter gene; RNA, Messenger - analysis; Spiperone; Spiperone - analogs & derivatives; Tomography, Emission-Computed; Transgenes; Transgenic animals; Tumors; β-Galactosidase; Animal model; Rodentia; Transgenic animal; Tissue specificity; Gene expression; In vivo; Vertebrata; Mammalia; Reporter gene; D2 Dopamine receptor; Mouse; Non invasive method; Molecular probe; Gene therapy; Emission tomography
• ISSN: 0969-7128; 1476-5462
• DOI: 10.1038/sj.gt.3300877

Reporter genes (e.g. beta-galactosidase, chloramphenicol-acetyltransferase, green fluorescent protein, luciferase) play critical roles in investigating mechanisms of gene expression in transgenic animals and in developing gene delivery systems for gene therapy. However, measuring expression of these reporter genes requires biopsy or death. We now report a procedure to image reporter gene expression repetitively and non-invasively in living animals with positron emission tomography (PET), using the dopamine type 2 receptor (D2R) as a reporter gene and 3-(2'-[18F]fluoroethyl)spiperone (FESP) as a reporter probe. We use a viral delivery system to demonstrate the ability of this PET reporter gene/PET reporter probe system to image reporter gene expression following somatic gene transfer. In mice injected intravenously with replication-deficient adenovirus carrying a D2R reporter gene, PET in vivo measures of hepatic [18F] retention are proportional to in vitro measures of hepatic FESP retention, D2R ligand binding and D2R mRNA. We use tumor-forming cells carrying a stably transfected D2R gene to demonstrate imaging of this PET reporter gene/PET reporter probe system in 'tissues'. Tumors expressing the transfected D2R reporter gene retain substantially more FESP than control tumors. The D2R/FESP reporter gene/reporter probe system should be a valuable technique to monitor, in vivo, expression from both gene therapy vectors and transgenes.