Organoid-based Anticancer Drug Screening

The AR-negative (AR-) MSK-PCa1 and AR-positive (AR+) MSK-PCa2 organoid lines were kindly provided by Dr. Wouter Karthaus and Prof. Dr. Jack Schalken from the Radboud University Medical Center. Organoids were cultured and passaged as described previously [9 (link),33 (link)], with the addition of synthetic androgen R1881 (1 nM; Sigma-Aldrich, Saint Louis, Missouri, USA, cat. no. R0908) for MSK-PCa2 organoids. Viability assays were conducted in pre-warmed 96-well plates (Costar, Corning, New York, NY, USA, cat. no. 3595) at a plating density of 2500 MSK-PCa1 or 5000 MSK-PCa2 organoid cells in 8 µL Matrigel domes (Corning, cat. no. 356231) per well. Single cells or organoids were incubated for 7 days with a dose range of docetaxel, cabazitaxel (0.01–10 nM; provided by Sanofi, Paris, France), abiraterone (0.03–30 µM; provided by Sanofi) or enzalutamide (0.03–30 µM; Axon Medchem, Groningen, the Netherlands, cat. no. 1613). Viability was measured with CellTiter-Glo 3D according to the manufacturer’s protocol (Promega, Madison, WI, USA, cat. no. G9681).