title: Role of activation peptide of procathepsin D in proliferation and invasion of lung cancer cells.
abstract: BACKGROUND
  Procathepsin D (pCD) secreted by cancer cells, increases proliferation, metastasis and progression of breast cancer, however its role in lung cancer is still unclear. The purified pCD and its synthetic activation peptide (AP) have shown similar proliferative effect on various cancer cell lines. The aim of this study is to clarify the role ofpCD and its AP in lung cancer by stable expression of pCD and pCD lacking its AP, in NCI-H23 lung cancer cells.
  
  
  METHODS
  The stable transfected clones were tested for cell proliferation, invasion and growth in nude mice. The effect of exogenous addition of purified pCD and its mutant proteins was also analyzed by proliferation assay.
  
  
  RESULTS
  The invasion and proliferation in vitro and tumor growth in vivo, demonstrated that the expression of pCD enhances the carcinogenic properties of NCI-H23 cells and that the AP is essential for these activities. Exogenous addition of purified proteins on various lung cancer cell lines showed that neither catalytic activity nor glycosylation are involved in the growth-promoting activity.
  
  
  CONCLUSIONS
  This is the first report of pCD cDNA expression in lung cancer cells that enhances the growth and invasion of these cells both in vitro and in vivo.
authors.affiliation: Department of Pathology, University of Louisville, Louisville, KY 40218, USA.
authors.forename: Aruna
authors.initials: A
authors.lastname: Vashishta
authors.forename: Sujata Saraswat
authors.initials: SS
authors.lastname: Ohri
authors.forename: Mary
authors.initials: M
authors.lastname: Proctor
authors.forename: Martin
authors.initials: M
authors.lastname: Fusek
authors.forename: Vaclav
authors.initials: V
authors.lastname: Vetvicka
mesh_terms: D002402:Cathepsin D / Q000737:chemistry / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D004792:Enzyme Precursors / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008175:Lung Neoplasms / Q000201:enzymology / Q000473:pathology*; D009361:Neoplasm Invasiveness; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D004792:Enzyme Precursors; C058345:procathepsin D; D002402:Cathepsin D