title: Serum-activated K and Cl currents underlay U87-MG glioblastoma cell migration.
abstract: Glioblastoma cells in vivo are exposed to a variety of promigratory signals, including undefined serum components that infiltrate into high grade gliomas as result of blood-brain barrier breakdown. Glioblastoma cell migration has been further shown to depend heavily on ion channels activity. We have then investigated the modulatory effects of fetal calf serum (FCS) on ion channels, and their involvement in U87-MG cells migration. Using the perforated patch-clamp technique we have found that, in a subpopulation of cells (42%), FCS induced: (1) an oscillatory activity of TRAM-34 sensitive, intermediate-conductance calcium-activated K (IK(Ca) ) channels, mediated by calcium oscillations previously shown to be induced by FCS in this cell line; (2) a stable activation of a DIDS- and NPPB-sensitive Cl current displaying an outward rectifying instantaneous current-voltage relationship and a slow, voltage-dependent inactivation. By contrast, in another subpopulation of cells (32%) FCS induced a single, transient IK(Ca) current activation, always accompanied by a stable activation of the Cl current. The remaining cells did not respond to FCS. In order to understand whether the FCS-induced ion channel activities are instrumental to promoting cell migration, we tested the effects of TRAM-34 and DIDS on the FCS-induced U87-MG cell migration using transwell migration assays. We found that these inhibitors were able to markedly reduce U87-MG cell migration in the presence of FCS, and that their co-application resulted in an almost complete arrest of migration. It is concluded that the modulation of K and Cl ion fluxes is essential for the FCS-induced glioblastoma cell migration.
authors.affiliation: Dipartimento di Biologia Cellulare e Ambientale, Universita' di Perugia, Perugia, Italy. fabiolab@unipg.it
authors.forename: Luigi
authors.initials: L
authors.lastname: Catacuzzeno
authors.forename: Francesco
authors.initials: F
authors.lastname: Aiello
authors.forename: Bernard
authors.initials: B
authors.lastname: Fioretti
authors.forename: Luigi
authors.initials: L
authors.lastname: Sforna
authors.forename: Emilia
authors.initials: E
authors.lastname: Castigli
authors.forename: Paola
authors.initials: P
authors.lastname: Ruggieri
authors.forename: Ada Maria
authors.initials: AM
authors.lastname: Tata
authors.forename: Antonella
authors.initials: A
authors.lastname: Calogero
authors.forename: Fabio
authors.initials: F
authors.lastname: Franciolini
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D001932:Brain Neoplasms / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005909:Glioblastoma / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008564:Membrane Potentials; D009361:Neoplasm Invasiveness; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism*; D011720:Pyrazoles / Q000494:pharmacology; D044967:Serum / Q000378:metabolism*; D013997:Time Factors
chemical_list: D018118:Chloride Channels; D002712:Chlorides; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; D011720:Pyrazoles; C411671:TRAM 34; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid; D011188:Potassium