title: Real-time monitoring of cell protrusion dynamics by impedance responses.
abstract: Cellular protrusions are highly dynamic structures involved in fundamental processes, including cell migration and invasion. For a cell to migrate, its leading edge must form protrusions, and then adhere or retract. The spatial and temporal coordination of protrusions and retraction is yet to be fully understood. The study of protrusion dynamics mainly relies on live-microscopy often coupled to fluorescent labeling. Here we report the use of an alternative, label-free, quantitative and rapid assay to analyze protrusion dynamics in a cell population based on the real-time recording of cell activity by means of electronic sensors. Cells are seeded on a plate covered with electrodes and their shape changes map into measured impedance variations. Upon growth factor stimulation the impedance increases due to protrusive activity and decreases following retraction. Compared to microscopy-based methods, impedance measurements are suitable to high-throughput studies on different cell lines, growth factors and chemical compounds. We present data indicating that this assay lends itself to dissect the biochemical signaling pathways controlling adhesive protrusions. Indeed, we show that the protrusion phase is sustained by actin polymerization, directly driven by growth factor stimulation. Contraction instead mainly relies on myosin action, pointing at a pivotal role of myosin in lamellipodia retraction.
authors.affiliation: 1] Department of Oncology, University of Torino, Torino, 10043, Italy [2] Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy.
authors.forename: Paolo Armando
authors.initials: PA
authors.lastname: Gagliardi
authors.affiliation: Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Puliafito
authors.affiliation: 1] Department of Oncology, University of Torino, Torino, 10043, Italy [2] Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: di Blasio
authors.affiliation: Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Chianale
authors.affiliation: 1] Department of Oncology, University of Torino, Torino, 10043, Italy [2] Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy.
authors.forename: Desiana
authors.initials: D
authors.lastname: Somale
authors.affiliation: 1] Department of Oncology, University of Torino, Torino, 10043, Italy [2] Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Seano
authors.affiliation: 1] Department of Oncology, University of Torino, Torino, 10043, Italy [2] Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy [3] Center for Molecular Systems Biology, University of Torino, 10124, Torino, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Bussolino
authors.affiliation: 1] Department of Oncology, University of Torino, Torino, 10043, Italy [2] Candiolo Cancer Institute-FPO IRCCS, Candiolo, 10060, Italy [3] Center for Molecular Systems Biology, University of Torino, 10124, Torino, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Primo
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D022081:Cell Surface Extensions / Q000502:physiology*; D000068818:Cetuximab / Q000494:pharmacology; D017097:Electric Impedance; D004815:Epidermal Growth Factor / Q000378:metabolism; D057809:HEK293 Cells; D006367:HeLa Cells; D017228:Hepatocyte Growth Factor / Q000378:metabolism; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D009218:Myosins / Q000037:antagonists & inhibitors; D011554:Pseudopodia / Q000502:physiology*; D053778:Thiazolidines / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; C066855:HGF protein, human; D006576:Heterocyclic Compounds, 4 or More Rings; D053778:Thiazolidines; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; C472645:blebbistatin; D004815:Epidermal Growth Factor; D017228:Hepatocyte Growth Factor; D009218:Myosins; D000068818:Cetuximab; C037067:latrunculin A