title: Collagen I but not Matrigel matrices provide an MMP-dependent barrier to ovarian cancer cell penetration.
abstract: BACKGROUND
  The invasive potential of cancer cells is usually assessed in vitro using Matrigel as a surrogate basement membrane. Yet cancer cell interaction with collagen I matrices is critical, particularly for the peritoneal metastatic route undertaken by several cancer types including ovarian. Matrix metalloprotease (MMP) activity is important to enable cells to overcome the barrier constraints imposed by basement membranes and stromal matrices in vivo. Our objective was to compare matrices reconstituted from collagen I and Matrigel as representative barriers for ovarian cancer cell invasion.
  
  
  METHODS
  The requirement of MMP activity for ovarian cancer cell penetration of Matrigel and collagen matrices was assessed in 2D transwell and 3D spheroid culture systems.
  
  
  RESULTS
  The broad range MMP inhibitor GM6001 completely prevented cell perforation of polymerised collagen I-coated transwell membranes. In contrast, GM6001 decreased ES-2 cell penetration of Matrigel by only approximately 30% and had no effect on HEY cell Matrigel penetration. In 3D culture, ovarian cancer cells grown as spheroids also migrated into surrounding Matrigel matrices despite MMP blockade. In contrast, MMP activity was required for invasion into 3D matrices of collagen I reconstituted from acid-soluble rat-tail collagen I, but not from pepsin-extracted collagen I (Vitrogen/Purecol), which lacks telopeptide regions.
  
  
  CONCLUSIONS
  Matrigel does not form representative barriers to ovarian cancer cells in either 2D or 3D culture systems. Our findings support the use of collagen I rather than Matrigel as a matrix barrier for invasion studies to better approximate critical interactions and events associated with peritoneal metastasis.
authors.affiliation: Department of Cell and Systems Biology, University of Toronto, Toronto, Canada. ksodek@csb.utoronto.ca <ksodek@csb.utoronto.ca>
authors.forename: Katharine L
authors.initials: KL
authors.lastname: Sodek
authors.forename: Theodore J
authors.initials: TJ
authors.lastname: Brown
authors.forename: Maurice J
authors.initials: MJ
authors.lastname: Ringuette
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002465:Cell Movement; D003094:Collagen / Q000737:chemistry*; D004338:Drug Combinations; D005260:Female; D006801:Humans; D007797:Laminin / Q000737:chemistry*; D020782:Matrix Metalloproteinases / Q000737:chemistry*; D018613:Microscopy, Confocal; D009361:Neoplasm Invasiveness; D010051:Ovarian Neoplasms / Q000378:metabolism / Q000473:pathology*; D010434:Pepsin A / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D011509:Proteoglycans / Q000737:chemistry*; D051381:Rats; D014945:Wound Healing
chemical_list: D004338:Drug Combinations; D007797:Laminin; D010455:Peptides; D011509:Proteoglycans; C059485:matrigel; D003094:Collagen; D010434:Pepsin A; D020782:Matrix Metalloproteinases