title: Automated tracking of unmarked cells migrating in three-dimensional matrices applied to anti-cancer drug screening.
abstract: In oncology, combating the spread of tumor cells is a clinical need which currently remains unsatisfied. Identifying anti-migratory compounds usually requires in vitro screening of a large number of molecules. Efficient and realistic (i.e., preferably 3D) in vitro tests are thus required in order to quantify the anti-migratory effects of anti-cancer drugs. To remain compatible with high-throughput screening, we focus on assays where unlabeled cells are migrating in 3D transparent gels and are observed under time-lapse 3D phase-contrast microscopy. In this context, we present a method for automatically tracking cells that combines a template matching preprocessing step with a mean-shift process. The preprocessing step consists in performing a correlation of a cell template with each observed volume in order to provide a phase-contrast artifact-free volume where the cells appear as correlation peaks surrounded by smooth gradients. This transformation enables the cells to be efficiently tracked by a mean-shift process. Robustness and efficiency of this approach are qualitatively and quantitatively shown in various experiments. Finally, we successfully applied our method to the quantitative characterization of the anti-migratory impact of cytochalasin-D on cancer cells. In conclusion, our method can efficiently be used for drug screening aiming to evidence drug-induced effects on cell migration in 3D transparent environments, such as matrix gels.
authors.affiliation: Laboratory of Image Synthesis and Analysis (LISA), Faculty of Applied Science, Université Libre de Bruxelles (U.L.B.), Brussels, Belgium.
authors.forename: Ivan
authors.initials: I
authors.lastname: Adanja
authors.forename: Olivier
authors.initials: O
authors.lastname: Debeir
authors.forename: Véronique
authors.initials: V
authors.lastname: Mégalizzi
authors.forename: Robert
authors.initials: R
authors.lastname: Kiss
authors.forename: Nadine
authors.initials: N
authors.lastname: Warzée
authors.forename: Christine
authors.initials: C
authors.lastname: Decaestecker
mesh_terms: D000465:Algorithms; D001331:Automation; D018929:Cell Culture Techniques / Q000379:methods; D045744:Cell Line, Tumor; D054443:Cell Migration Assays / Q000379:methods*; D002465:Cell Movement / Q000187:drug effects; D003094:Collagen; D015638:Cytochalasin D / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor / Q000379:methods*; D005782:Gels; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008858:Microscopy, Phase-Contrast / Q000379:methods; D015203:Reproducibility of Results
chemical_list: D005782:Gels; D015638:Cytochalasin D; D003094:Collagen