DU145 cells were obtained from the American Type Culture Collection (ATCC, Manassas, VA). All experiments with cell line were performed within 6 months of receipt from ATCC or resuscitation after cryopreservation. ATCC uses Short Tandem Repeat (STR) profiling for testing and authentication of cell lines. C4-2B cells were kindly provided and authenticated by Dr. Leland Chung, Cedars-Sinai Medical Center, Los Angeles, CA. The cells were cultured in RPMI-1640 medium containing 10% complete fetal bovine serum (FBS) with 100 units/ml penicillin and 0.1 mg/ml streptomycin and maintained at 37°C in a humidified incubator with 5% CO2. C4-2B cells were incubated with gradually increasing concentrations of docetaxel. Cells that survived the maximum concentration of docetaxel were stored for further analysis and referred to as TaxR cells. Parental C4-2B cells were passaged alongside the docetaxel treated cells as an appropriate control. Docetaxel resistant TaxR cells were maintained in 5 nM docetaxel-containing medium. Docetaxel (CAS#114977-28-5) was purchased from TSZ CHEM (Framingham, MA). Apigenin (CAS#520-36-5) was purchased from Sigma-Aldrich (Saint Louis, MO). Antibodies against ABCB1 and GAPDH were obtained from Santa Cruz Biotechnologies (Santa Cruz, CA).