title: ABT-263 enhances sorafenib-induced apoptosis associated with Akt activity and the expression of Bax and p21((CIP1/WAF1)) in human cancer cells.
abstract: OBJECTIVE
  Sorafenib, a potent inhibitor that targets several kinases associated with tumourigenesis and cell survival, has been approved for clinical treatment as a single agent. However, combining sorafenib with other agents improves its anti-tumour efficacy in various preclinical tumour models. ABT-263, a second-generation BH3 mimic, binds to the anti-apoptotic family members Bcl-2, Bcl-xL and Bcl-w, and has been demonstrated to enhance TNFSF10 (TRAIL)-induced apoptosis in human hepatocarcinoma cells. Hence, we investigated the effects of ABT-263 treatment combined with sorafenib.
  
  
  METHODS
  The effects of ABT-263 combined with sorafenib were investigated in vitro, on cell viability, clone formation and apoptosis, and the mechanism examined using western blot and flow cytometry. This combination was also evaluated in vivo, in a mouse xenograft model; tumour growth, volume and weights were measured and a TUNEL assay performed.
  
  
  RESULTS
  ABT-263 enhanced sorafenib-induced apoptosis while sparing non-tumourigenic cells. Although ABT-263 plus sorafenib significantly stimulated intracellular reactive oxygen species production and subsequent mitochondrial depolarization, this was not sufficient to trigger cell apoptosis. ABT-263 plus sorafenib significantly decreased Akt activity, which was, at least partly, involved in its effect on apoptosis. Bax and p21 (CIP1/WAF1) were shown to play a critical role in ABT-263 plus sorafenib-induced apoptosis. Combining sorafenib with ABT-263 dramatically increased its efficacy in vivo.
  
  
  CONCLUSIONS
  The anti-tumour activity of ABT-263 plus sorafenib may involve the induction of intrinsic cell apoptosis via inhibition of Akt, and reduced Bax and p21 expression. Our findings offer a novel effective therapeutic strategy for tumour treatment.
authors.affiliation: College of Life Sciences, Wuhan University, Wuhan, Hubei, China.
authors.forename: Jingru
authors.initials: J
authors.lastname: Li
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Chen
authors.forename: Jiali
authors.initials: J
authors.lastname: Wan
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Chunrong
authors.initials: C
authors.lastname: Yu
authors.forename: Wenhua
authors.initials: W
authors.lastname: Li
mesh_terms: D000814:Aniline Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004357:Drug Synergism; D006801:Humans; D020287:In Situ Nick-End Labeling; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009369:Neoplasms / Q000188:drug therapy* / Q000473:pathology; D009536:Niacinamide / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D010671:Phenylurea Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism; D000077157:Sorafenib; D013449:Sulfonamides / Q000008:administration & dosage / Q000494:pharmacology*; D023041:Xenograft Model Antitumor Assays; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
chemical_list: D000814:Aniline Compounds; D050759:Cyclin-Dependent Kinase Inhibitor p21; D010671:Phenylurea Compounds; D017382:Reactive Oxygen Species; D013449:Sulfonamides; D051028:bcl-2-Associated X Protein; D009536:Niacinamide; D000077157:Sorafenib; D051057:Proto-Oncogene Proteins c-akt; C528561:navitoclax
keywords: ABT-263; cancer; combination therapy; sorafenib