title: Stimulatory effects of the multi-kinase inhibitor sorafenib on human bladder cancer cells.
abstract: OBJECTIVE
  Sorafenib is an inhibitor of several intracellular signalling kinases with anti-proliferative, anti-angiogenic and pro-apoptotic effects in tumour cells. Sorafenib is used in the therapy of advanced renal cell carcinoma, and several phase II clinical trials are being carried out in patients with urothelial carcinomas.
  
  
  METHODS
  Using a panel of human bladder cancer cell lines (RT4, T24, J82), we characterized systematically the effects of sorafenib on intracellular signalling, migration, proliferation and apoptosis.
  
  
  RESULTS
  We demonstrated that at low concentrations (<1 microM), sorafenib is capable of significantly stimulating migration and proliferation of the bladder cancer cells. We hypothesize that these stimulatory effects on tumour cell functions might be explained by an activation of the Ras/ERK-1/2 signal transduction pathway. In addition, the comparison of different bladder cancer cell lines not only revealed a different biology (e.g. cell migration), but also a differential susceptibility to the anti-apoptotic effects of sorafenib. Finally, we confirmed in different bladder cancer cell lines the known inhibitory actions of sorafenib in pharmacological concentrations (> or =3 microM) on ERK-1/2 phosphorylation, migration and proliferation, as well as the pro-apoptotic effects of the compound.
  
  
  CONCLUSIONS
  Taken together, these findings suggest that although sorafenib has the potential to be used in the treatment of urothelial carcinoma, this compound might also activate bladder cancer cells at low concentrations. This should be relevant for dosing regiments to optimize the treatment with this promising anti-tumour drug.
authors.affiliation: Klinik für Urologie, Universitätsklinikum Essen, Universität Duisburg-Essen, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Rose
authors.forename: M
authors.initials: M
authors.lastname: Grandoch
authors.forename: F
authors.initials: F
authors.lastname: vom Dorp
authors.forename: H
authors.initials: H
authors.lastname: Rübben
authors.forename: A
authors.initials: A
authors.lastname: Rosenkranz
authors.forename: J W
authors.initials: JW
authors.lastname: Fischer
authors.forename: A-A
authors.initials: AA
authors.lastname: Weber
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001557:Benzenesulfonates / Q000494:pharmacology* / Q000627:therapeutic use; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D006801:Humans; D009536:Niacinamide / Q000031:analogs & derivatives; D010671:Phenylurea Compounds; D011485:Protein Binding; D047428:Protein Kinase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D011725:Pyridines / Q000494:pharmacology* / Q000627:therapeutic use; D000077157:Sorafenib; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology; D018631:ras Proteins / Q000378:metabolism
chemical_list: D017304:Annexin A5; D000970:Antineoplastic Agents; D001557:Benzenesulfonates; D010671:Phenylurea Compounds; D047428:Protein Kinase Inhibitors; D011725:Pyridines; D009536:Niacinamide; D000077157:Sorafenib; D018631:ras Proteins