Referenced in: none

Automatically associated channels: Kv1.1 , Kv1.2 , Kv1.3 , Slo1

Title: KV1.1 K(+) channels identification in human breast carcinoma cells: involvement in cell proliferation.

Authors: H Ouadid-Ahidouch, F Chaussade, M Roudbaraki, C Slomianny, E Dewailly, P Delcourt, N Prevarskaya

Journal, date & volume: Biochem. Biophys. Res. Commun., 2000 Nov 19 , 278, 272-7

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/11097830

Abstract
Electrophysiological, immunocytochemical, and RT-PCR methods were used to identify a K(+) conductance not yet described in MCF-7 human breast cancer cells. A voltage-dependent and TEA-sensitive K(+) current was the most commonly observed in these cells. The noninactivating K(+) current (I(K)) was insensitive to iberiotoxin (100 nM) and charybdotoxin (100 nM) but reduced by alpha-dendrotoxin (alpha-DTX). Perfusion of alpha-DTX reduced a fraction of I(K) amplitude in a dose-dependent manner (IC(50) = 0.6 +/- 0.3 nM). This DTX sensitive I(K) exhibited a voltage threshold at -20 mV and was not inactivated. The time constant of activation was 5.3 +/- 2.2 ms measured at +60 mV. The averaged half-activation potential and slope factor values were 14 +/- 1.6 mV and 10 +/- 1.4, respectively. Immunocytochemical analysis demonstrated that plasma membrane was labeled by anti-Kv1.1 but not by anti-Kv1.2 nor anti-Kv1.3 antibodies. Furthermore, only Kv1.1 mRNA was detected in MCF-7 cells. Incubation in 1 and 10 nM alpha-DTX reduced cell proliferation by 20 and 30%, respectively. These data provide the first evidence of Kv1.1 K(+) channels expression in MCF-7 cells and indicate that these channels are implicated in cell proliferation.