1. CXCL12-induced glioblastoma cell migration requires intermediate conductance [Ca.sup.2+]-activated [K.sup.+] channel activity
- Author
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Sciaccaluga, Miriam, Fioretti, Bernard, Catacuzzeno, Luigi, Pagani, Francesca, Bertollini, Cristina, Rosito, Maria, Catalano, Myriam, D'Alessandro, Giuseppina, Santoro, Antonio, Cantore, Giampaolo, Ragozzino, Davide, Castigli, Emilia, Franciolini, Fabio, and Limatola, Cristina
- Subjects
Glioblastoma multiforme -- Health aspects ,Cytokines -- Health aspects ,Brain tumors -- Development and progression ,Biological sciences - Abstract
The activation of ion channels is crucial during cell movement, including glioblastoma cell invasion in the brain parenchyma. In this context, we describe for the first time the contribution of intermediate conductance [Ca.sup.2+]-activated K ([IK.sub.ca]) channel activity in the chemotactic response of human glioblastoma cell lines, primary cultures, and freshly dissociated tissues to CXC chemokine ligand 12 (CXCL12), a chemokine whose expression in glioblastoma has been correlated with its invasive capacity. We show that blockade of the [IK.sub.Ca] channel with its specific inhibitor 1-[(2-chlorophenyl) diphenylmethyl]-1H-pyrazole (TRAM-34) or [IK.sub.Ca] channel silencing by short hairpin RNA (shRNA) completely abolished CXCL12-induced cell migration. We further demonstrate that this is not a general mechanism in glioblastoma cell migration since epidermal growth factor (EGF), which also activates [IK.sub.Ca] channels in the glioblastoma-derived cell line GL15, stimulate cell chemotaxis even if the [IK.sub.Ca] channels have been blocked or silenced. Furthermore, we demonstrate that both CXCL12 and EGF induce [Ca.sup.2+] mobilization and [IK.sub.Ca] channel activation but only CXCL12 induces a long-term upregulation of the [IK.sub.Ca] channel activity. Furthermore, the [Ca.sup.2+]-chelating agent BAPTA-AM abolished the CXCL12-induced, but not the EGF-induced, glioblastoma cell chemotaxis. In addition, we demonstrate that the extracellular signal-regulated kinase (ERK)1/2 pathway is only partially implicated in the modulation of CXCL12-induced glioblastoma cell movement, whereas the phosphoinositol-3 kinase (PI3K) pathway is not involved. In contrast, EGF-induced glioblastoma migration requires both ERK1/2 and PI3K activity. All together these findings suggest that the efficacy of glioblastoma invasiveness might be related to an array of nonoverlapping mechanisms activated by different chemotactic agents. chemokines; transwell; tumor; TRAM-34; short hairpin RNA doi: 10.1152/ajpcell.00344.2009.
- Published
- 2010