Ovarian Cancer Cell Lines for ABCG2 Inhibitor Study

Igrov1 human ovarian carcinoma cells and an Igrov1-derived cell line overexpressing ABCG2, Igrov1/T8, were generously provided by Dr. Douglas Ross at the University of Maryland and were received in 2011. Cells were cultured in RPMI 1640 medium (Gibco, InVitrogen Corporation, Carlsbad, CA) supplemented with 10% fetal bovine serum (Gibco), 1% penicillin/streptomycin (Gibco), and 5 ng/L ciprofloxacin (Bayer Pharmaceuticals, Berkeley, CA) and maintained at 37°C in an incubator with an atmosphere of 95% air and 5% CO₂. The Igrov1/T8 ABCG2 overexpressing phenotype was maintained by exposure to 950 nM topotecan hydrochloride hydrate (Sigma, Saint Louis, MO) for one hour per week on a day that the cells were not expanded. We synthesized and identified three ABCG2-selective efflux inhibitors, CID44640177, CID1434724, and CID46245505, by high-throughput flow cytometry as previously reported.(28 (link),29 ) For the purposes of this manuscript we will refer to the ABCG2 inhibitors CID44640177, CID1434724, and CID46245505 as 177, 724, and 505, respectively.