title: Apoptosis sensitizers enhance cytotoxicity in hepatoblastoma cells.
abstract: OBJECTIVE
  Drug resistance remains a major challenge for the treatment of high-risk hepatoblastoma (HB). To enhance effectiveness of chemotherapy we modulate apoptosis in HB cells in vitro.
  
  
  METHODS
  Viability was monitored in HB cells (HuH6, HepT1) and fibroblasts in monolayer and spheroid cultures treated with ABT-737, obatoclax, HA14-1, and TW-37 and each in combination with CDDP, etoposide, irinotecan, paclitaxel, and DOXO in a MTT assay. Western blot analyses were performed to determine expressions of pro- and anti-apoptotic proteins.
  
  
  RESULTS
  Obatoclax and ABT-737 led to a dose-dependent decrease of viability in HB cells at concentrations above 0.3 μM. TW-37 and HA14-1 were less effective. ABT-737 and obatoclax had additive effects when combined with CDDP, etoposide, irinotecan, paclitaxel, or DOXO. This was also observed for fibroblast, however, for higher drug concentrations. In spheroid cultures, relative expression of Bcl-XL was increased, Bax was decreased, Mcl-1 was low, and Bcl-2 was not detected compared to 2D cultures, denoting an anti-apoptotic state in spheroids. Obatoclax and ABT-737 have overcome the resistance to CDDP. HuH6 cells have shown higher susceptability for apoptosis sensitizers than HepT1.
  
  
  CONCLUSIONS
  The data provide evidence that ABT-737 and obatoclax might improve treatment results in children with HB.
authors.affiliation: Department of Pediatric Surgery and Pediatric Urology, University Children's Hospital, Hoppe-Seyler-Strasse 1, 72076, Tübingen, Germany. justus.lieber@med.uni-tuebingen.de
authors.forename: Justus
authors.initials: J
authors.lastname: Lieber
authors.forename: Verena
authors.initials: V
authors.lastname: Ellerkamp
authors.forename: Julia
authors.initials: J
authors.lastname: Wenz
authors.forename: Bettina
authors.initials: B
authors.lastname: Kirchner
authors.forename: Steven W
authors.initials: SW
authors.lastname: Warmann
authors.forename: Jörg
authors.initials: J
authors.lastname: Fuchs
authors.forename: Sorin
authors.initials: S
authors.lastname: Armeanu-Ebinger
mesh_terms: D017209:Apoptosis; D001549:Benzamides / Q000494:pharmacology*; D001578:Benzopyrans / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000494:pharmacology*; D015153:Blotting, Western; D002470:Cell Survival; D019008:Drug Resistance, Neoplasm; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018197:Hepatoblastoma / Q000188:drug therapy / Q000473:pathology*; D006801:Humans; D007211:Indoles; D008113:Liver Neoplasms / Q000188:drug therapy / Q000473:pathology*; D009570:Nitriles / Q000494:pharmacology*; D009596:Nitrophenols / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000037:antagonists & inhibitors; D011758:Pyrroles / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology*; D013450:Sulfones / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: C501332:ABT-737; D001549:Benzamides; D001578:Benzopyrans; D001713:Biphenyl Compounds; D004791:Enzyme Inhibitors; D007211:Indoles; D009570:Nitriles; D009596:Nitrophenols; D010879:Piperazines; D019253:Proto-Oncogene Proteins c-bcl-2; D011758:Pyrroles; D013449:Sulfonamides; D013450:Sulfones; C515128:TW-37 compound; C456800:ethyl 2-amino-6-bromo-4-(1-cyano-2-ethoxy-2-oxoethyl)-4H-chromene-3-carboxylate; C520962:obatoclax