RT Journal Article SR Electronic T1 Development of A Real-Time in Vivo Transcription Assay: Application Reveals Pregnane X Receptor-Mediated Induction of CYP3A4 by Cancer Chemotherapeutic Agents JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 439 OP 445 DO 10.1124/mol.62.3.439 VO 62 IS 3 A1 Erin Schuetz A1 Lubin Lan A1 Kazuto Yasuda A1 Richard Kim A1 Thomas A. Kocarek A1 John Schuetz A1 Stephen Strom YR 2002 UL http://molpharm.aspetjournals.org/content/62/3/439.abstract AB We report the development of a rapid real-time assay that measures the transcription of luciferase reporter genes in transduced mouse hepatic cells in vivo. Luciferase activity is noninvasively measured by whole-body optical imaging within hours of the hydrodynamic injection of as little as 1 μg of naked DNA. Transcription of genes introduced as linearized DNA can be serially assayed for weeks in each animal. Transcription was quantified by extracorporal monitoring of bioluminescence as well as or better than by traditional in vitro bioluminescence assay. Our assay allows the measurement of transcription as it occurs, under the most informative biological conditions (i.e., in a living, intact organ). Furthermore, it substantially reduces the cost, time, and number of animals required for analysis of gene expression. The utility of the method is demonstrated in the discovery that topotecan and etoposide are ligands of pregnane X receptor that induce CYP3A4 transcription.