Beta-subunits of voltage-gated sodium channels in human prostate cancer: quantitative in vitro and in vivo analyses of mRNA expression.

We previously identified high levels of Na(v)1.7 voltage-gated sodium channel alpha-subunit (VGSCalpha) mRNA and protein in human prostate cancer cells and tissues. Here, we investigated auxillary beta-subunit (VGSCbetas) expression. In vitro, the combined expression of all four VGSCbetas was significantly (approximately 4.5-fold) higher in strongly compared to weakly metastatic cells. This was mainly due to increased beta1-expression, which was under androgenic control. In vivo, beta1-beta4 mRNAs were detectable and their expression in CaP vs non-CaP tissues generally reflected the in vitro levels in relation to metastatic potential. The possible role(s) of VGSCbetas (VGSCalpha-associated and VGSCalpha-independent) in prostate cancer are discussed.