Title: Na(V)1.5 enhances breast cancer cell invasiveness by increasing NHE1-dependent H(+) efflux in caveolae.

Authors: L Brisson, L Gillet, S Calaghan, P Besson, J-Y Le Guennec, S Roger, J Gore

Journal, date & volume: Oncogene, 2011 Apr 28 , 30, 2070-6

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/21170089

Abstract
Na(V)1.5 sodium channels enhance the invasiveness of breast cancer cells through the acidic-dependent activation of cysteine cathepsins. Here, we showed that the Na(+)/H(+) exchanger type 1 (NHE1) was an important regulator of H(+) efflux in breast cancer cells MDA-MB-231 and that its activity was increased by Na(V)1.5. Na(V)1.5 and NHE1 were colocalized in membrane rafts containing caveolin-1. The inhibition of Na(V)1.5 or NHE1 induced a similar reduction in cell invasiveness and extracellular matrix degradation; no additive effect was observed when they were simultaneously inhibited. Our study suggests that Na(V)1.5 and NHE1 are functionally coupled and enhance the invasiveness of cancer cells by increasing H(+) efflux.