title: [Relation of advanced oxidation protein products with VEGF and TGF-β1 in colon cancer cells exposed to intermittent hypoxia].
abstract: OBJECTIVE
  To investigate the association of advanced oxidation protein products (AOPP) with oxidative stress in colon cancer cells exposed to intermittent hypoxia (IH).
  
  
  METHODS
  Colon cancer SW480 cells were exposed to IH, continuous hypoxia, or normoxia. Enzyme-linked immunosorbent assay (ELISA) was employed to examine the levels of AOPP and vascular endothelial growth factor (VEGF), xanthine oxidase assay was used to determine malonaldehyde (MDA) and glutathione peroxidase (GSH-PX), and Western blotting and immunofluorescence assay were performed for detection of transforming growth factor-β(1) (TGF-β(1)) expression.
  
  
  RESULTS
  Compared with the normoxia group, the two hypoxia groups showed significantly increased AOPP and MDA levels (P<0.05) and lowered SOD and GSH-PX levels (P<0.05). The concentration of AOPP was positively correlated to MDA, VEGF, and TGF-β(1) levels (P<0.05), but inversely to SOD. No significant correlation was found between AOPP and GSH-PX levels.
  
  
  CONCLUSIONS
  Compared with continuous hypoxia, IH results in more obvious protein oxidation in relation to oxidative stress. The increased expression of VEGF and TGF-β(1) in the context of hypoxia is closely related to AOPP level.
authors.affiliation: Center of Sleep Medicine, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China. xianlw16@yahoo.com.cn
authors.forename: Le-Wu
authors.initials: LW
authors.lastname: Xian
authors.forename: Tao-Ping
authors.initials: TP
authors.lastname: Li
authors.forename: Yi-Er
authors.initials: YE
authors.lastname: Wei
authors.forename: Si-Pei
authors.initials: SP
authors.lastname: Wu
authors.forename: Lei
authors.initials: L
authors.lastname: Ma
mesh_terms: D062107:Advanced Oxidation Protein Products / Q000378:metabolism*; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000378:metabolism*; D006801:Humans; D018384:Oxidative Stress; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
chemical_list: D062107:Advanced Oxidation Protein Products; C508960:TGFB1 protein, human; D053773:Transforming Growth Factor beta1; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A