Brackenbury, William J. orcid.org/0000-0001-6882-3351, Chioni, Athina-Myrto, Diss, James K. J. et al. (1 more author) (2007) The neonatal splice variant of Nav1.5 potentiates in vitro invasive behaviour of MDA-MB-231 human breast cancer cells. BREAST CANCER RESEARCH AND TREATMENT. pp. 149-160. ISSN 0167-6806
Abstract
Upregulation of functional voltage-gated Na+ channels (VGSCs) occurs in metastatic human breast cancer (BCa) in vitro and in vivo. The present study aimed to ascertain the specific involvement of the 'neonatal' splice variant of Nav1.5 (nNav1.5), thought to be predominant, in the VGSC-dependent invasive behaviour of MDA-MB-231 cells. Functional activity of nNav1.5 was suppressed by two different methods targeting nNav1.5: (i) small interfering RNA (siRNA), and (ii) a polyclonal antibody (NESO-pAb); effects upon migration and invasion were determined. nNav1.5 mRNA, protein and signalling were measured using real-time PCR, Western blotting, and patch clamp recording, respectively. Treatment with the siRNA rapidly reduced (by similar to 90%) the level of nNav1.5 (but not adult Nav1.5) mRNA, but the protein reduction was much smaller (similar to 30%), even after 13 days. Nevertheless, the siRNA reduced peak VGSC current density by 33%, and significantly increased the cells' sensitivity to nanomolar tetrodotoxin (TTX). Importantly, the siRNA suppressed in vitro migration by 43%, and eliminated the normally inhibitory effect of TTX. Migrated MDA-MB-231 cells expressed more nNav1.5 protein at the plasma membrane than non-migrated cells. Furthermore, NESO-pAb reduced migration by up to 42%, in a dose-dependent manner. NESO-pAb also reduced Matrigel invasion without affecting proliferation. TTX had no effect on cells already treated with NESO-pAb. It was concluded that nNav1.5 is primarily responsible for the VGSC-dependent enhancement of invasive behaviour in MDA-MB-231 cells. Accordingly, targeting nNav1.5 expression/activity may be useful in clinical management of metastatic BCa.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Keywords: | antibody,breast cancer,metastasis,RNAi,voltage-gated Na+ channel,HUMAN PROSTATE-CANCER,NA+ CHANNEL EXPRESSION,GATED SODIUM-CHANNEL,ROOT GANGLION NEURONS,RNA INTERFERENCE,LUNG-CANCER,METASTATIC CASCADE,MEMBRANE-ACTIVITY,RAT,LINE |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Biology (York) |
Depositing User: | Pure (York) |
Date Deposited: | 19 Feb 2013 13:05 |
Last Modified: | 16 Oct 2024 12:08 |
Published Version: | https://doi.org/10.1007/s10549-006-9281-1 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1007/s10549-006-9281-1 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:52903 |