Human glioblastoma multiform (GBM) is a highly malignant brain tumour characterized by elevated angiogenesis. Intermediate conductance calcium activated potassium channels (KCa3.1) is overexpressed in human GBM tissue compared to healthy human normal brain, and the involvement in angiogenesis process is not yet investigate. To verify this aspect, we study the effects of TRAM-34, selective inhibitors of KCa3.1, in ex-vivo model based on graft of GBM cell on the chorioallontoic membrane (CAM) of chick embryo by evaluating morphometric, histologic and gene expression markers. The TRAM-34 reduce vascularity when applied in the area near to GBM implant, whereas have not effect, when applied in the normal developing CAM area. Gene expression analysis confirm an anti-angiogenic effect of TRAM-34 in CAM-GBM ex vivo model. We further studied the effects of angiogenic factor SDF-1 (Stromal Derivated Factor-1, ligand of CXCR4) and anti-angiogenic agents such as LY294009 (an inhibitor of PI3Ks) and silver nanoparticles (AgNPs) on KCa3.1 current expressed in GBM cell lines (U251 and GL-15). Utilizing the patch clamp technique, we observed that short pre-incubation of SDF-1 increased KCa3.1 current, whereas LY294009 and AgNPs reduced the same current. By utilizing fibroblast models (NIH-3T3 wt and NIH-3T3 EAG1-G440s expressing cell), we study the effect of hypoxia in KCa3.1 current regulation. Hypoxia upregulate endogenous Kca3.1 current when co-expressed with proangiogenic EAG1 gene, whereas is not able to regulated Kca3.1 current in wt model. We propose that KCa3.1 channel is involved in signalling of GBM angiogenesis and can represent a new anti-angiogenic target in GBM therapy.
Short Talks - Role of KCa3.1 channels in glioblastoma induced angiogenesis
Fioretti B.;Cataldi S.;Ragonese F.;Mancinelli L.;Barberini L.;Albi E.;Beccari T;
2017
Abstract
Human glioblastoma multiform (GBM) is a highly malignant brain tumour characterized by elevated angiogenesis. Intermediate conductance calcium activated potassium channels (KCa3.1) is overexpressed in human GBM tissue compared to healthy human normal brain, and the involvement in angiogenesis process is not yet investigate. To verify this aspect, we study the effects of TRAM-34, selective inhibitors of KCa3.1, in ex-vivo model based on graft of GBM cell on the chorioallontoic membrane (CAM) of chick embryo by evaluating morphometric, histologic and gene expression markers. The TRAM-34 reduce vascularity when applied in the area near to GBM implant, whereas have not effect, when applied in the normal developing CAM area. Gene expression analysis confirm an anti-angiogenic effect of TRAM-34 in CAM-GBM ex vivo model. We further studied the effects of angiogenic factor SDF-1 (Stromal Derivated Factor-1, ligand of CXCR4) and anti-angiogenic agents such as LY294009 (an inhibitor of PI3Ks) and silver nanoparticles (AgNPs) on KCa3.1 current expressed in GBM cell lines (U251 and GL-15). Utilizing the patch clamp technique, we observed that short pre-incubation of SDF-1 increased KCa3.1 current, whereas LY294009 and AgNPs reduced the same current. By utilizing fibroblast models (NIH-3T3 wt and NIH-3T3 EAG1-G440s expressing cell), we study the effect of hypoxia in KCa3.1 current regulation. Hypoxia upregulate endogenous Kca3.1 current when co-expressed with proangiogenic EAG1 gene, whereas is not able to regulated Kca3.1 current in wt model. We propose that KCa3.1 channel is involved in signalling of GBM angiogenesis and can represent a new anti-angiogenic target in GBM therapy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
