title: [Effect of ionization on the expression of hypoxia-inducible factor-1alpha and VEGF in hepatocellular carcinoma HepG2 cells under anoxic condition].
abstract: OBJECTIVE
  To investigate the effect of ionization on the expression of hypoxia-inducible factor-1alpha and vascular endothelial growth factor (VEGF) in human hepatocellular carcinoma HepG2 cells under anoxic condition, and search for an effective method for improving the radiosensitivity of the tumor cells.
  
  
  METHODS
  HepG2 cells were divided into 4 groups, namely the control group, hypoxia group, ionization radiation group, and hypoxia and radiation group, with corresponding treatments. The cell apoptosis was detected by fluorescence microscope, and the cell viability analyzed by MTT assay. The expressions of HIF-1alpha and VEGF mRNAs were detected by RT-PCR.
  
  
  RESULTS
  A few apoptotic cells were found in hypoxia group, but significant apoptosis occurred in the radiation group; fewer apoptotic cells were observed in the hypoxia and radiation group than in the hypoxia group. The viable cell fraction increased in the order of the control group>hypoxia group> hypoxia plus radiation group> radiation group (P<0.05), and the expression of HIF-1alpha mRNA increased in the order of hypoxia plus radiation group>hypoxia group>radiation group (P<0.05), and no significant difference was found in the radiation group and control group. The expression of VEGF mRNA increased in the order of hypoxia plus radiation group> hypoxia group>radiation group>control group (P<0.05).
  
  
  CONCLUSIONS
  The expression of HIF-1alpha may protect the hepatocellular carcinoma cells from damages by radiation in hypoxic condition, and HIF-1alpha decreases the radiosensitivity of the cells possibly by inducing VEGF expression.
authors.affiliation: Department of Radiotherapy, Fuzhou General Hospital of Nanjing Command, Fuzhou 350025, China.
authors.forename: Hui-hua
authors.initials: HH
authors.lastname: Cheng
authors.forename: Zhi-chao
authors.initials: ZC
authors.lastname: Fu
authors.forename: Feng-mei
authors.initials: FM
authors.lastname: Wang
mesh_terms: D017209:Apoptosis; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000532:radiotherapy; D015687:Cell Hypoxia; D002470:Cell Survival; D056945:Hep G2 Cells; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000378:metabolism* / Q000528:radiation effects; D011839:Radiation, Ionizing; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism* / Q000528:radiation effects
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A