title: [Sensitivity to bortezomib of RPIM8226 cells after co-cultured with down-regulated Cav-1 expression HUVECs].
abstract: OBJECTIVE
  To investigate the sensitivity to bortezomib of RPMI8226 cells after co-cultured with down-regulated Caveolin (Cav)-1 expression of HUVECs by transfection with Cav-1 shRNA (HUVECs(Cav-1 low)).
  
  
  METHODS
  Exposure to bortezomib with or without 50 nmol/L dexamethasone at different concentration, the proliferation of RPMI8226 was analyzed by MTT assay when it was cultured alone or co-cultured with HUVECs(Cav-1 low). Cav-1 expression was detected by using of Western blot and cell cycle, apoptosis and the level of reactive oxygen species (ROS) were analyzed by flow cytometry.
  
  
  RESULTS
  Cav-1 expression was notably down-regulated in HUVECs(Cav-1 low) (0.2199±0.0288 vs 1.3195±0.2393) (P<0.01). The IC(50) of bortezomib for RPMI8226 cultured alone, co-cultured with HUVECs orHUVECCav- 1 low were 20 nmol/L, 50 nmol/L and 65 nmol/L, respectively. The percentages of G₀/G₁ phase in RPMI8226 cultured alone, co-cultured with HUVECs and HUVECs(Cav-1 low) were 28.49%, 30.41%, and 36.15% respectively. The protection of RPMI 8226 against apoptosis by HUVECs was demonstrated that the apoptosis/death rates were 66.8%, 10.7% and 8.6% in RPMI8226 cultured alone, co-cultured with HUVECs and HUVECs(Cav-1 low) after exposure to 20 nmol/L bortezomib for 24 h. RPMI8226 could induce the oxidative stress of HUVECs before and after co-culture. The ROS level was raised from 15.0% to 35.2% in RPMI8226, from 80.4% to 91.0% in HUVECs, and from 84.6% to 96.8% in HUVECs(Cav-1 low).
  
  
  CONCLUSIONS
  The down-regulated Cav-1 expression of HUVECs could promote proliferation and induce apoptosis of RMPI8226 cells, lead to G₀/G₁ phase arrest, and reduce the sensitivity to bortezomib.
authors.affiliation: Departmentof Hematology, Second Affiliated Hospital of Soochow University, Soochow 215004, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Chen
authors.forename: Song-guang
authors.initials: SG
authors.lastname: Ju
authors.forename: Zi-yan
authors.initials: ZY
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Yu-qing
authors.initials: YQ
authors.lastname: Yuan
authors.forename: Jin-xiang
authors.initials: JX
authors.lastname: Fu
mesh_terms: D017209:Apoptosis; D001897:Boronic Acids / Q000494:pharmacology*; D000069286:Bortezomib; D051242:Caveolin 1 / Q000378:metabolism*; D045744:Cell Line, Tumor / Q000187:drug effects; D002478:Cells, Cultured; D018920:Coculture Techniques; D015536:Down-Regulation; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D009101:Multiple Myeloma; D011719:Pyrazines / Q000494:pharmacology*
chemical_list: D001897:Boronic Acids; D051242:Caveolin 1; D011719:Pyrazines; D000069286:Bortezomib