title: Post-transcriptionally regulated expression system in human xenogeneic transplantation models.
abstract: Cells have developed a mechanism to discriminate between premature termination codons (PTCs) and normal stop codons during translation, sparking vigorous research to develop drugs promoting readthrough at PTCs to treat genetic disorders caused by PTCs. It was posed that this concept could also be applied to regulated gene therapy protocols by incorporating a PTC into a therapeutic gene, so active protein would only be made after administration of a readthrough agent. The strengths of the system are highlighted here by results demonstrating: (i) background expression levels were reduced to 0.01% to 0.0005% of wild type in unselected mass populations of cells depending upon the specific stop codon utilized and its position within the gene; (ii) expression levels responded well to multiple "On" and "Off" regulation cycles in vivo in human xenograft systems; (iii) the level of induction approached three logs using aminoglycoside activators including NB54, a newly synthesized aminoglycoside with significantly reduced toxicity; and (iv) expression levels could be appreciably altered when employing different promoters in a variety of cell types. These results strongly support the contention that this system should have important clinical applications when tight control of gene expression is required.
authors.affiliation: Department of Molecular Genetics, Microbiology and Immunology, Robert Wood Johnson Medical School-University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08854, USA.
authors.forename: Hui-Ling Rose
authors.initials: HL
authors.lastname: Lee
authors.forename: Chiann-Chyi
authors.initials: CC
authors.lastname: Chen
authors.forename: Timor
authors.initials: T
authors.lastname: Baasov
authors.forename: Yacov
authors.initials: Y
authors.lastname: Ron
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Dougherty
mesh_terms: D000617:Aminoglycosides / Q000235:genetics / Q000378:metabolism; D000818:Animals; D018389:Codon, Nonsense / Q000235:genetics; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D051379:Mice; D008817:Mice, Mutant Strains; D023421:Models, Animal; D016716:PC12 Cells; D012323:RNA Processing, Post-Transcriptional / Q000235:genetics*; D012333:RNA, Messenger; D051381:Rats; D014183:Transplantation, Heterologous / Q000379:methods*
chemical_list: D000617:Aminoglycosides; D018389:Codon, Nonsense; D012333:RNA, Messenger