title: Cyclooxygenase-2 inhibition prevents migration of colorectal cancer cells to extracellular matrix by down-regulation of matrix metalloproteinase-2 expression.
abstract: OBJECTIVE
  Matrix metalloproteinases-2 hydrolyses gelatins and collagens. It has many biologic functions, including cancer cells invasion. Overexpression of cyclooxygenase-2 is known to be involved in colorectal carcinogenesis, although the mechanism is unclear. Up-regulation of matrix metalloproteinases-2 expression may be one of the mechanisms, which explains how cyclooxygenase-2 expression promotes migration of colorectal cancer cells to extracellular matrix.
  
  
  METHODS
  Colorectal cancer cell lines HT29, CaCO2, and Colo205 were used. By using flow cytometry, their cyclooxygenase-2 expression was determined. These cell lines were modulated with NS398, a selective cyclooxygenase-2-inhibitor, and prostaglandin-E2. Western blot and enzyme-linked inmmunosorbent assay were used to determine these cells' matrix metalloproteinases-2 expression. These cell lines' ability to migrate into extracellular matrix was determined by MatrigelR (Millipore, Watford, UK) Invasion Chamber.
  
  
  RESULTS
  HT29 expressed more cyclooxygenase-2 than CaCO2. Cyclooxygenase-2 was not detected in Colo205. Matrix metalloproteinases-2 expression is highest in HT29 and least in Colo205. Cyclooxygenase-2 inhibition by NS398 showed decreased matrix metalloproteinases-2 expression in HT29 and CaCO2, but not Colo205, reversible with prostaglandin-E2. Prostaglandin-E2 was shown to up-regulate matrix metalloproteinases-2 expression in all cell lines. MatrigelR Invasion Chamber demonstrated that many more HT29 cells migrate across the membrane than CaCO2 and Colo205, and cyclooxygenase-2 inhibition reduced cellular migration in the cyclooxygenase-2-positive cell lines. Prostaglandin-E2 promoted migration in all cell lines.
  
  
  CONCLUSIONS
  There is a positive relationship between cyclooxygenase-2 and matrix metalloproteinases-2 expression. The latter is modulated by prostaglandin-E2 in all cell lines and NS398 in cyclooxygenase-2-positive cells. Such modulation has a knock-on effect to the cells' ability to invade into extracellular matrix. Cyclooxygenase-2 and matrix metalloproteinases-2 expression are potential therapeutic targets into prevention of colorectal cancer metastasis.
authors.affiliation: Department of General Surgery, University Hospital Coventry, Walsgrave, West Midlands, CV2 9DX, United Kingdom. ed.leung@doctors.org.uk
authors.forename: Edmund
authors.initials: E
authors.lastname: Leung
authors.forename: David
authors.initials: D
authors.lastname: McArthur
authors.forename: Alan
authors.initials: A
authors.lastname: Morris
authors.forename: Nigel
authors.initials: N
authors.lastname: Williams
mesh_terms: D000704:Analysis of Variance; D015153:Blotting, Western; D002465:Cell Movement / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000201:enzymology / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000378:metabolism; D052246:Cyclooxygenase 2 Inhibitors / Q000494:pharmacology*; D015536:Down-Regulation; D004797:Enzyme-Linked Immunosorbent Assay; D005109:Extracellular Matrix; D005434:Flow Cytometry; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D009578:Nitrobenzenes / Q000494:pharmacology*; D013449:Sulfonamides / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D052246:Cyclooxygenase 2 Inhibitors; D009578:Nitrobenzenes; D013449:Sulfonamides; C080955:N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide; D051546:Cyclooxygenase 2; D020778:Matrix Metalloproteinase 2