Development of Fluorine-18 Labeled Metabolically Activated Tracers for Imaging of Drug Efflux Transporters with Positron Emission Tomography
                                
                                    
                                        作者:Kerstin Sander、Eva Galante、Thibault Gendron、Elena Yiannaki、Niral Patel、Tammy L. Kalber、Adam Badar、Mathew Robson、Sean P. Johnson、Florian Bauer、Severin Mairinger、Johann Stanek、Thomas Wanek、Claudia Kuntner、Tim Kottke、Lilia Weizel、David Dickens、Kjell Erlandsson、Brian F. Hutton、Mark F. Lythgoe、Holger Stark、Oliver Langer、Matthias Koepp、Erik Årstad                                    
                                    
                                        DOI:10.1021/acs.jmedchem.5b00652
                                    
                                    
                                        日期:2015.8.13
                                    
                                    Increased activity of efflux transporters, e.g., P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP), at the blood brain barrier is a pathological hallmark of many neurological diseases, and the resulting multiple drug resistance represents a major clinical challenge. Noninvasive imaging of transporter activity can help to clarify the underlying mechanisms of drug resistance and facilitate diagnosis, patient stratification, and treatment monitoring. We have developed a metabolically activated radiotracer for functional imaging of P-gp/BCRP activity with positron emission tomography (PET). In preclinical studies, the tracer showed excellent initial brain uptake and clean conversion to the desired metabolite, although at a sluggish rate. Blocking with P-gp/BCRP modulators led to increased levels of brain radioactivity; however, dynamic PET did not show differential clearance rates between treatment and control groups. Our results provide proof-of-concept for development of prodrug tracers for imaging of P- /BCRP function in vivo but also highlight some challenges associated with this strategy.