title: Trophoblast stem cells differentiate in vitro into invasive trophoblast giant cells.
abstract: Trophoblast cells are characterized by an invasive behavior into the surrounding uterine tissue. In rodents, an early peri-/endovascular type of invasion exerted by trophoblast giant cells can be distinguished from a late interstitial type carried out by glycogen trophoblast cells. Analysis of the molecular mechanisms of trophoblast invasion has been hampered, however, by the complex temporal and spatial patterns of invasion. We utilized trophoblast stem (TS) cell lines to study trophoblast invasion in vitro and to establish a model that facilitates investigation of this process on the molecular level. Our results showed that trophoblast giant cells that differentiate from TS cells in vitro are capable of penetrating a reconstituted basement membrane matrix. Consequently, invasion rates were increased in various giant cell differentiation-promoting conditions. We also derived TS cell lines that are homozygous for a mutation of the Hand1 transcription factor. The Hand1-/- TS cells showed reduced levels of giant cell differentiation and exhibited an approximately 50% decrease in invasion rates. In summary, trophoblast giant cells that differentiate from TS cells in vitro recapitulate the invasive capacity of normal trophoblast cells in vivo. The TS cell system is a valuable tool to identify and quantitatively study regulators of trophoblast invasion.
authors.affiliation: Genes and Development Research Group, Department of Biochemistry and Molecular Biology, Health Sciences Center, University of Calgary, Calgary, Alberta, Canada T2N 4N1. myriam.hemberger@bbsrc.ac.uk
authors.forename: Myriam
authors.initials: M
authors.lastname: Hemberger
authors.forename: Martha
authors.initials: M
authors.lastname: Hughes
authors.forename: James C
authors.initials: JC
authors.lastname: Cross
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000378:metabolism; D051792:Basic Helix-Loop-Helix Proteins; D015152:Blotting, Northern; D002454:Cell Differentiation / Q000502:physiology*; D017931:DNA Primers; D004054:Diethylstilbestrol / Q000378:metabolism; D005260:Female; D015726:Giant Cells / Q000378:metabolism / Q000502:physiology*; D066298:In Vitro Techniques; D051379:Mice; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D010929:Placentation / Q000502:physiology*; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics; D014212:Tretinoin / Q000378:metabolism; D014327:Trophoblasts / Q000166:cytology* / Q000502:physiology*
chemical_list: D051792:Basic Helix-Loop-Helix Proteins; D017931:DNA Primers; D004054:Diethylstilbestrol; D014157:Transcription Factors; D014212:Tretinoin; C095572:Hand1 protein, mouse