title: Vascular endothelial growth factor antisense pretreatment of bladder cancer cells significantly enhances the cytotoxicity of mitomycin C, gemcitabine and Cisplatin.
abstract: OBJECTIVE
  Due to unsatisfactory success in the treatment of local and systemic bladder cancer and the low response rates to commonly used chemotherapy (CT) alternative and additive approaches must be found. The function of vascular endothelial growth factor (VEGF) in neo-angiogenesis and, therefore, in solid tumors makes it a promising target for a specific antitumor therapy. We investigated the possibility of sensitizing transitional bladder cancer cell lines to CT by pretreatment with VEGF antisense (AS) oligodeoxynucleotides (AS-ODNs).
  
  
  METHODS
  The human bladder cancer cell lines EJ28 and 5637 were transiently transfected with 3 antiVEGF AS-ODNs, followed by incubation with 3 doses of mitomycin C, gemcitabine or cisplatin CT. WST-1 (a sodium salt of 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate) assay (Roche, Mannheim, Germany) was performed to assess effects on cell viability. Apoptosis was examined by Annexin V staining. In all experiments a nonsense ODN served as a control.
  
  
  RESULTS
  Each cell line responded in a dose dependent manner to all CTs. Combined treatment with VEGF AS-ODNs and CT resulted in decreased viability compared with isolated CT. VEGF857 plus CT significantly decreased the viability of the 2 cell lines compared with nonsense ODN plus CT for all 3 CT agents (p <0.007). This detected chemosensitization was based on an AS mediated increase in apoptosis.
  
  
  CONCLUSIONS
  One of the 3 AS-ODNs tested (VEGF857) significantly sensitizes human transitional cell carcinoma cells to CT. We suggest VEGF as an additional putative target to enhance the therapeutic benefit of, for example mitomycin C and gemcitabine instillation treatment schedules.
authors.affiliation: Institutes of Biochemistry, Technical University Dresden, Dresden, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Krause
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Förster
authors.forename: Kai
authors.initials: K
authors.lastname: Kraemer
authors.forename: Susanne
authors.initials: S
authors.lastname: Fuessel
authors.forename: Matthias
authors.initials: M
authors.lastname: Kotzsch
authors.forename: Uta
authors.initials: U
authors.lastname: Schmidt
authors.forename: Manfred P
authors.initials: MP
authors.lastname: Wirth
authors.forename: Axel
authors.initials: A
authors.lastname: Meye
authors.forename: Bernd
authors.initials: B
authors.lastname: Schwenzer
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017209:Apoptosis / Q000187:drug effects; D002295:Carcinoma, Transitional Cell / Q000188:drug therapy* / Q000473:pathology; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000008:administration & dosage; D003841:Deoxycytidine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006801:Humans; D016685:Mitomycin / Q000008:administration & dosage; D016376:Oligonucleotides, Antisense / Q000627:therapeutic use*; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*; D000093542:Gemcitabine
chemical_list: D016376:Oligonucleotides, Antisense; D042461:Vascular Endothelial Growth Factor A; D003841:Deoxycytidine; D016685:Mitomycin; D002945:Cisplatin; D000093542:Gemcitabine