title: The emerging role of QSOX1 in cancer.
abstract: CONCLUSIONS
  Quiescin sulfhydryl oxidase 1 (QSOX1) is an enzyme that oxidizes thiols during protein folding, reducing molecular oxygen to hydrogen peroxide. Tumor cells may take advantage of oxidative environments at different stages of tumorigenesis, but QSOX1 may also serve additional functions in tumors.
  
  
  BACKGROUND
  Several groups have reported the over-expression of QSOX1 in breast, pancreas, and prostate cancers. A consensus is building that QSOX1 over-expression is important during tumor cell invasion, facilitating tumor cell migration at the tumor-stroma interface. As such, QSOX1 may be considered a prognostic indicator of metastatic potential or even indicate that cancer is present in a host.
  
  
  RESULTS
  However, some controversy exists between QSOX1 as a marker of poor or favorable outcome in breast cancer. More studies are required to reveal what advantage QSOX1 provides to breast and other types of cancer. More specifically, it is critical to learn which tumor types over-express QSOX1 and use its enzymatic activity to their advantage.
  
  
  CONCLUSIONS
  As interest increases in understanding the mechanisms of tumorigenesis within the extracellular matrix and how tumor cells influence fibroblasts and other stromal cells, QSOX1 may be revealed as an important player in cancer detection and prognosis. Defining the mechanism(s) of QSOX1 activity in tumors and in in vivo models will provide important insights into how to target QSOX1 with anti-neoplastic agents.
authors.affiliation: 1 School of Life Sciences, ASU/Mayo Clinic , Scottsdale, Arizona.
authors.forename: Douglas F
authors.initials: DF
authors.lastname: Lake
authors.forename: Douglas O
authors.initials: DO
authors.lastname: Faigel
mesh_terms: D063646:Carcinogenesis / Q000235:genetics*; D005109:Extracellular Matrix / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D058990:Molecular Targeted Therapy; D009369:Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D050862:Oxidoreductases Acting on Sulfur Group Donors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D050862:Oxidoreductases Acting on Sulfur Group Donors; C117183:QSOX1 protein, human