title: HIF1 contributes to hypoxia-induced pancreatic cancer cells invasion via promoting QSOX1 expression.
abstract: BACKGROUND
  Quiescin sulfhydryl oxidase 1 (QSOX1), which oxidizes sulfhydryl groups to form disulfide bonds in proteins, is found to be over-expressed in various pancreatic cancer cell lines and patients. QSOX1 promotes invasion of pancreatic cancer cells by activating MMP-2 and MMP-9. However, its regulatory mechanism remains largely undefined.
  
  
  METHODS
  Real-time PCR and Western blot were employed to detect the expression of QSOX1 in human pancreatic cancer cell lines under hypoxic condition. Luciferase reporter and ChIP assays were used to assess the regulation of QSOX1 by hypoxia-inducible factor 1 (HIF-1). Small interfering RNA (siRNA) was applied to knock down endogenous expression of QSOX1. Matrigel-coated invasion chamber essays were conducted to detect the invasion capacity of QSOX1-depleted cells.
  
  
  RESULTS
  Both hypoxia and hypoxia mimicking reagent up-regulated the expression of QSOX1 in human pancreatic cancer cell lines. Knockdown of HIF-1α eliminated hypoxia induced QSOX1 expression. HIF-1α was found directly bound to two hypoxia-response elements (HRE) of QSOX1 gene, both of which were required for HIF-1 induced QSOX1 expression. Moreover, QSOX1 silencing blocked hypoxia-induced pancreatic cancer cells invasion.
  
  
  CONCLUSIONS
  QSOX1 is a direct target of HIF-1 and may contribute to hypoxia-induced pancreatic cancer cells invasion.
authors.affiliation: Department of General Surgery, Zhongshan Hospital, Fudan University, 136 Yi Xue Yuan Road, Shanghai, China.
authors.forename: Chen-Ye
authors.initials: CY
authors.lastname: Shi
authors.forename: Yue
authors.initials: Y
authors.lastname: Fan
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Lou
mesh_terms: D015687:Cell Hypoxia; D045744:Cell Line, Tumor; D002465:Cell Movement; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D010190:Pancreatic Neoplasms; D011485:Protein Binding; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D020218:Response Elements; D015854:Up-Regulation
chemical_list: D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D050862:Oxidoreductases Acting on Sulfur Group Donors; C117183:QSOX1 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9