title: [CoCl2-induced chemotherapy resistance in SW480 cells and its mechanism].
abstract: OBJECTIVE
  To observe the proliferation of SW480 cells exposed to different concentrations of CoCl2, and to examine the expression of hypoxiainducible factor-1 alpha (HIF-1alpha) and heme oxygenase-1 (HO-1) during hypoxia to explore the chemotherapy resistance effect and role of HIF-1alpha and HO-1.
  
  
  METHODS
  Methyl thiazolyl tetrazolium (MTF) method was used to detect the proliferation of SW480 cells in the presence of fluorouracil (FU). RT-PCR was applied to examine the expression of HIF-1alpha and HO-1 mRNA in hypoxia.
  
  
  RESULTS
  SW480 cells were proliferated at a slow rate, and had a strong resistance to FU with the increase of CoCl2. RT-PCR showed that the up-regulated expression of HIF-1alpha and HO-1 mRNA was consistent with the dose-effect curve and time-effect curve.
  
  
  CONCLUSIONS
  The hypoxia induced by CoCl2 can inhibit the proliferation of SW480, and it can also decrease the sensitivity of the cell to FU. The mechanism is probably related to the up-regulated expression of HIF-1alpha and HO-1 mRNA.
authors.affiliation: Xiangya School of Medicine, Central South University, Changsha, China.
authors.forename: Ze-ming
authors.initials: ZM
authors.lastname: Tan
authors.forename: Ying
authors.initials: Y
authors.lastname: Wu
authors.forename: Hua-li
authors.initials: HL
authors.lastname: Zhang
authors.forename: Xian-zhong
authors.initials: XZ
authors.lastname: Xiao
mesh_terms: D016587:Antimutagenic Agents / Q000494:pharmacology; D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D003035:Cobalt / Q000494:pharmacology*; D003110:Colonic Neoplasms / Q000473:pathology*; D019008:Drug Resistance, Neoplasm / Q000187:drug effects*; D005472:Fluorouracil / Q000494:pharmacology*; D051547:Heme Oxygenase-1 / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D051793:Hypoxia-Inducible Factor 1 / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D016587:Antimutagenic Agents; D051793:Hypoxia-Inducible Factor 1; D012333:RNA, Messenger; D003035:Cobalt; D051547:Heme Oxygenase-1; C018021:cobaltous chloride; D005472:Fluorouracil