Reporter genes (eg β-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.

Heparin, the most widely used anticoagulant drug in the world today, remains an animal-derived product with the attendant risks of adulteration and contamination. A contamination crisis in 2007–2008 increased the impetus to provide non-animal-derived sources of heparin, produced under cGMP conditions. In addition, recent studies suggest that heparin may have significant antineoplastic activity, separate and distinct from its anticoagulant activity, while other studies indicate a role for heparin in treating inflammation, infertility, and infectious disease. A variety of strategies have been proposed to produce a bioengineered heparin. In this review, we discuss several of these strategies including microbial production, mammalian cell production, and chemoenzymatic modification. We also propose strategies for creating “designer” heparins and heparan-sulfates with various biochemical and physiological properties.

We performed a comparative analysis on CHO cells with varying recombinant monoclonal antibody production rates (qAb) and investigated the regulation of MAb production. Two families of CHO cells each ...