title: Real time non-invasive imaging of receptor-ligand interactions in vivo.
abstract: Non-invasive longitudinal detection and evaluation of gene expression in living animals can provide investigators with an understanding of the ontogeny of a gene's biological function(s). Currently, mouse model systems are used to optimize magnetic resonance imaging (MRI), positron emission tomography (PET), single-photon emission computed tomography (SPECT), and optical imaging modalities to detect gene expression and protein function. These molecular imaging strategies are being developed to assess tumor growth and the tumor microenvironment. In addition, pre-labeling of progenitor cells can provide invaluable information about the developmental lineage of stem cells both in organogenesis and tumorigenesis. The feasibility of this approach has been extensively tested by targeting of endogenous tumor cell receptors with labeled ligand (or ligand analog) reporters and targeting enzymes with labeled substrate (or substrate analog). We will primarily discuss MRI, PET, and SPECT imaging of cell surface receptors and the feasibility of non-invasive imaging of gene expression using the tumor microenvironment (e.g., hypoxia) as a conditional regulator of gene expression.
authors.affiliation: Department of Radiology, MRI Division, Johns Hopkins University, Traylor 340, 720 Rutland Avenue, Baltimore, Maryland 21205-2196, USA.
authors.forename: Paul
authors.initials: P
authors.lastname: Winnard
authors.forename: Venu
authors.initials: V
authors.lastname: Raman
mesh_terms: D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology; D002352:Carrier Proteins / Q000378:metabolism; D058973:Folate Receptors, GPI-Anchored; D005786:Gene Expression Regulation; D006801:Humans; D008024:Ligands; D008279:Magnetic Resonance Imaging; D051379:Mice; D008958:Models, Molecular; D011401:Promoter Regions, Genetic / Q000235:genetics; D011956:Receptors, Cell Surface / Q000378:metabolism*; D017481:Receptors, Somatostatin / Q000378:metabolism; D011990:Receptors, Transferrin / Q000378:metabolism; D014055:Tomography, Emission-Computed; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000888:Antibodies, Anti-Idiotypic; D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D008024:Ligands; D011956:Receptors, Cell Surface; D017481:Receptors, Somatostatin; D011990:Receptors, Transferrin; C093733:somatostatin receptor 2