title: Cell invasion in the spheroid sprouting assay: a spatial organisation analysis adaptable to cell behaviour.
abstract: The endothelial cell spheroid assay provides a suitable in vitro model to study (lymph) angiogenesis and test pro- and anti-(lymph) angiogenic factors or drugs. Usually, the extent of cell invasion, observed through optical microscopy, is measured. The present study proposes the spatial distribution of migrated cells as a new descriptor of the (lymph) angiogenic response. The utility of this novel method rests with its capacity to locally characterise spheroid structure, allowing not only the investigation of single and collective cell invasion but also the evolution of the spheroid core itself. Moreover, the proposed method can be applied to 2D-projected spheroid images obtained by optical microscopy, as well as to 3D images acquired by confocal microscopy. To validate the proposed methodology, endothelial cell invasion was evaluated under different experimental conditions. The results were compared with widely used global parameters. The comparison shows that our method prevents local spheroid modifications from being overlooked and leading to the possible misinterpretation of results.
authors.affiliation: Laboratory of tumor and developmental biology, GIGA-Cancer, University of Liège, Liège, Belgium.
authors.forename: Silvia
authors.initials: S
authors.lastname: Blacher
authors.affiliation: Laboratory of tumor and developmental biology, GIGA-Cancer, University of Liège, Liège, Belgium.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Erpicum
authors.affiliation: Laboratory of tumor and developmental biology, GIGA-Cancer, University of Liège, Liège, Belgium; Laboratory of cardiovascular research, CRP santé, Luxembourg, Luxembourg.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Lenoir
authors.affiliation: Laboratory of tumor and developmental biology, GIGA-Cancer, University of Liège, Liège, Belgium.
authors.forename: Jenny
authors.initials: J
authors.lastname: Paupert
authors.affiliation: GIGA-Imaging and Flow Cytometry Platform, University of Liege, Liege, Belgium.
authors.forename: Gustavo
authors.initials: G
authors.lastname: Moraes
authors.affiliation: GIGA-Imaging and Flow Cytometry Platform, University of Liege, Liege, Belgium.
authors.forename: Sandra
authors.initials: S
authors.lastname: Ormenese
authors.affiliation: GIGA Systems Biology and Chemical Biology, University of Liege, Liege, Belgium.
authors.forename: Eric
authors.initials: E
authors.lastname: Bullinger
authors.affiliation: Laboratory of tumor and developmental biology, GIGA-Cancer, University of Liège, Liège, Belgium.
authors.forename: Agnès
authors.initials: A
authors.lastname: Noel
mesh_terms: D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects / Q000235:genetics; D058948:Cell Tracking / Q000379:methods*; D042783:Endothelial Cells / Q000187:drug effects / Q000648:ultrastructure*; D006801:Humans; D021621:Imaging, Three-Dimensional; D018613:Microscopy, Confocal; D009389:Neovascularization, Pathologic / Q000188:drug therapy / Q000235:genetics*; D018874:Spheroids, Cellular / Q000187:drug effects / Q000648:ultrastructure*; D019098:Telomerase / Q000737:chemistry / Q000302:isolation & purification; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry / Q000378:metabolism
chemical_list: D020533:Angiogenesis Inhibitors; D042461:Vascular Endothelial Growth Factor A; C509186:TERT protein, human; D019098:Telomerase