Xanthohumol

Human CCA cell lines (CCLP-1 and SG-231), derived from intrahepatic biliary epithelium, were obtained from Dr. Anthony J. Demetris from the University of Pittsburgh. The CC-SW-1 cell line was kindly provided by Dr. Nabeel Bardeesy, Harvard Medical School. All cell lines were authenticated before receiving them. CCLP-1 cells were grown in Dulbecco Modified Eagle Medium (DMEM; Sigma-Aldrich, St. Louis, MO) with 1% penicillin/streptomycin (P/S; Life Technologies, Carlsbad, CA), 10% fetal bovine serum (FBS; Life Technologies), 1% 4-(2-hydroxyethyl)-1-piperazineethanesulfonic (HEPES; Life Technologies), and 1% non-essential amino acids (NEAA; Life Technologies). SG-231 cells were grown in Minimal Essential Medium alpha-1 (MEMα-1; Life Technologies) with 10% FBS, 1% P/S, and 1% HEPES [16 (link)]. CC-SW-1 cells were grown in Roswell Park Memorial Institute (RPMI) 1640 medium with 10% FBS and 1% P/S. Cells were grown in a 37°C humidified incubator in 5% CO₂. Xanthohumol (Tocris, Minneapolis, MN or Selleckchem.com, Houston, TX) was dissolved in dimethyl sulfoxide (DMSO; Sigma-Aldrich).

Three human neuroblastoma (NB) cell lines (SK-N-AS, NGP, and SH-SY-5Y) were used in this study, and SK-N-AS and SH-SY-5Y were purchased from ATCC. The NGP was a kind gift from Dr. Thiele. The cells were grown in Roswell Park Memorial Institute Media (RPMI; Life Technologies, Carlsbad, CA), supplemented with 10% fetal bovine serum (Sigma-Aldrich, St. Louis, MO), 100 IU/mL penicillin, and 100 μg/mL streptomycin (Life Technologies) in a humidified atmosphere of 5% CO₂ in air at 37°C. Xanthohumol (Tocris, Minneapolis, MN or Selleckchem, Houston, TX) was dissolved in dimethyl sulfoxide (DMSO: Sigma-Aldrich) to prepare stock solutions of 50 mM. An equivalent volume of DMSO alone served as a negative control. TRAIL/Apo-2L was purchased from PeproTech (Rocky Hill, New Jersey, USA) and stored in aliquots at -80°C.