title: ABCG2/BCRP expression modulates D-Luciferin based bioluminescence imaging.
abstract: Bioluminescence imaging (BLI) is becoming indispensable to the study of transgene expression during development and, in many in vivo models of disease such as cancer, for high throughput drug screening in vitro. Because reaction of d-luciferin with firefly luciferase (fLuc) produces photons of sufficiently long wavelength to permit imaging in intact animals, use of this substrate and enzyme pair has become the method of choice for performing BLI in vivo. We now show that expression of the ATP-binding cassette (ABC) family transporter ABCG2/BCRP affects BLI signal output from the substrate d-luciferin. In vitro studies show that d-luciferin is a substrate for ABCG2/BCRP but not for the MDR1 P-glycoprotein (ABCB1/Pgp), multidrug resistance protein 1 (MRP1/ABCC1), or multidrug resistance protein 2 (MRP2/ABCC2). d-Luciferin uptake within cells is shown to be modulated by ABC transporter inhibitors, including the potent and selective ABCG2/BCRP inhibitor fumitremorgin C. Images of xenografts engineered to express transgenic ABCG2/BCRP, as well as xenografts derived from the human prostate cancer cell line 22Rv1 that naturally express ABCG2/BCRP, show that ABCG2/BCRP expression and function within regions of interest substantially influence d-luciferin-dependent bioluminescent output in vivo. These findings highlight the need to consider ABCG2/BCRP effects during d-luciferin-based BLI and suggest novel high throughput methods for identifying new ABCG2/BCRP inhibitors.
authors.affiliation: Russell H. Morgan Department of Radiology, The Johns Hopkins Bloomberg School of Public Health, The Johns Hopkins School of Medicine, Baltimore, Maryland, USA.
authors.forename: Yimao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Bressler
authors.forename: Jeff
authors.initials: J
authors.lastname: Neal
authors.forename: Bachchu
authors.initials: B
authors.lastname: Lal
authors.forename: Hyo-Eun C
authors.initials: HE
authors.lastname: Bhang
authors.forename: John
authors.initials: J
authors.lastname: Laterra
authors.forename: Martin G
authors.initials: MG
authors.lastname: Pomper
mesh_terms: D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000096:biosynthesis*; D000818:Animals; D045744:Cell Line, Tumor; D004285:Dogs; D005260:Female; D049454:Firefly Luciferin / Q000032:analysis / Q000378:metabolism*; D006801:Humans; D049409:Luciferases, Firefly / Q000378:metabolism; D049408:Luminescent Agents / Q000032:analysis / Q000378:metabolism; D008163:Luminescent Measurements; D008297:Male; D051379:Mice; D008819:Mice, Nude; D000089762:Multidrug Resistance-Associated Protein 2; D009363:Neoplasm Proteins / Q000096:biosynthesis*; D011471:Prostatic Neoplasms / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: C000715087:ABCC2 protein, human; C116614:ABCG2 protein, human; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D049408:Luminescent Agents; D000089762:Multidrug Resistance-Associated Protein 2; D009363:Neoplasm Proteins; D049454:Firefly Luciferin; D049409:Luciferases, Firefly