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ENaC/Degenerin family members reduces glioblastoma whole well current and inhibits cell migration
Author(s) -
Kapoor Niren,
Fuller Catherine M,
Benos Dale J
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.937.29
Subject(s) - epithelial sodium channel , glioma , patch clamp , gene knockdown , amiloride , sodium channel , immunoprecipitation , cancer research , ion channel , western blot , chemistry , biology , microbiology and biotechnology , cell culture , electrophysiology , neuroscience , sodium , biochemistry , receptor , genetics , gene , organic chemistry
High‐grade gliomas display a basally active, amiloride sensitive current not seen in normal astrocytes or low‐grade gliomas. We hypothesize that this glioma current is mediated by a hybrid channel composed of a mixture of Epithelial Sodium Channel (ENaC)/ Degenerins (Deg) subunits. Knocking down ASIC1 using siRNA in U251‐ MG glioma cells reduced the amiloride sensitive whole cell patch clamp current by 60–70% and ASIC1 protein expression by 50%. Knocking down γENaC using dominant negative mutation (S155X) in D54‐MG glioma cells reduced the whole cell patch clamp current by over 50%. γENaC protein expression was nearly completely abolished as shown by Western blot. αENaC dominant negative mutation (E34X) had a similar effect upon glioma cell whole cell current as γENaC knockdown. Using co‐immunoprecipitation, we also demonstrated an interaction between ASIC1 and γENaC suggesting that these subunits interact with each other to form an ion channel in D54‐MG glioma cell. Our study also suggests that knocking down either γ‐ or αENaC inhibits glioma cell migration by 30–40% consistent with the hypothesis that these channels play a role in glioma cell migration. Therefore ENaC/Deg members play an important role in glioblastoma pathophysiology, and knocking down these different subunits changes important characteristics of glioma cells. This study was supported by NIH Grant CA101952.