title: Investigation of an in vitro model of trophoblast invasion.
abstract: OBJECTIVE
  To re-investigate methods for visualising cytotrophoblast invasion using the Matrigel invasion model.
  
  
  METHODS
  Cytotrophoblast cells were isolated from pooled first trimester placentae and cultured on Matrigel-coated transwells in media supplemented with either 5 ng/ml vascular endothelial growth factor (VEGF) or 10 ng/ml epidermal growth factor (EGF). Invasion was visualised using standard and confocal fluorescent microscopy.
  
  
  RESULTS
  The purity of the enriched cytotrophoblast cells was 84-100%. Immunofluorescent cytokeratin staining examined with an inverted fluorescent microscope suggested that cytokeratin-positive cells were present on the underside of the membrane, having invaded through the Matrigel on the upper surface. However, confocal microscopy indicated that these cells did not invade through the Matrigel, and no viable cells were identified in the culture media below the membrane.
  
  
  CONCLUSIONS
  These results suggest that cytokeratin-positive staining on Matrigel-coated transwells is not necessarily indicative of cell invasion, and that similar studies should be interpreted with caution depending on the method of quantification.
authors.affiliation: School of Biochemistry and Molecular Biology, University of Leeds, Leeds, LS2 9JT, United Kingdom.
authors.forename: A J
authors.initials: AJ
authors.lastname: Trew
authors.forename: G E
authors.initials: GE
authors.lastname: Lash
authors.forename: P N
authors.initials: PN
authors.lastname: Baker
mesh_terms: D001672:Biocompatible Materials / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002469:Cell Separation; D002478:Cells, Cultured; D003094:Collagen / Q000187:drug effects / Q000378:metabolism; D004338:Drug Combinations; D016228:Endothelial Growth Factors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005109:Extracellular Matrix / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007797:Laminin / Q000187:drug effects / Q000378:metabolism; D008222:Lymphokines / Q000494:pharmacology; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011509:Proteoglycans / Q000187:drug effects / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
chemical_list: D001672:Biocompatible Materials; D004338:Drug Combinations; D016228:Endothelial Growth Factors; D007797:Laminin; D008222:Lymphokines; D011509:Proteoglycans; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; C059485:matrigel; D004815:Epidermal Growth Factor; D003094:Collagen