Mechanistic insights into Nav1.7‐dependent regulation of rat prostate cancer cell invasiveness revealed by toxin probes and proteomic analysis

Abstract

Voltage‐gated sodium channels are involved in tumor metastasis, as potentiating or attenuating their activities affects the migration and invasion process of tumor cells. In the present study, we tested the effect of two peptide toxins, JZTX‐I and HNTX‐III which function as Nav1.7 activator and inhibitor, respectively, on the migration and invasion ability of prostate cancer (PCa) cell line Mat‐LyLu. These two peptides showed opposite effects, and subsequently a comparative proteomic analysis characterized 64 differentially expressed membrane proteins from the JZTX‐I‐ and HNTX‐III‐treated groups. Among these, 15 proteins were down‐regulated and 49 proteins were up‐regulated in the HNTX‐III group. Bioinformatic analysis showed eight proteins are cytoskeleton proteins or related regulators, which might play important roles in the metastasis of Mat‐LyLu cells. The altered expressions of four of these proteins, fascin, muskelin, annexin A2, and cofilin‐1, were validated by western blot analysis. Further function network analysis of these proteins revealed that the Rho family GTPases RhoA and Rac1 might be of particular importance for the rat PCa cell invasion. Pharmacological data revealed that JZTX‐I and HNTX‐III could modulate the Rho signaling pathway in a Nav1.7‐dependent manner. In summary, this study suggests that the Nav1.7‐dependent regulation of Rho GTPase activity plays a vital role in Mat‐LyLu cell migration and invasion and provides new insights into the treatment of PCa.

Voltage-dependent activation of Rac1 by Nav1.5 channels promotes cell migration

“…Our findings agree with another study in H460 non-small cell lung cancer cells, in which Nav1.7 channels were shown to depolarize the Vm by ~10 mV (Campbell et al, 2013). Thus, the mechanism identified here is likely applicable to other non-excitable cell types where VGSCs are expressed (Chen et al, 2019;Grimes et al, 1995;Carrie D House et al, 2010;Persson et al, 2014;Zhou et al, 2015). In addition, it has previously been shown that VGSCs contribute to steady-state Vm depolarization and viability in rat optic nerve axons and spinal cord astrocytes over a time course of hours (Sontheimer, Fernandez-Marques, Ullrich, Pappas, & Waxman, 1994;Stys, Sontheimer, Ransom, & Waxman, 1993), suggesting that this mechanism persists over an extended period.…”

Voltage‐dependent activation of Rac1 by Nav1.5 channels promotes cell migration

“…Our findings agree with another study in H460 non‐small cell lung cancer cells, in which Na v 1.7 channels were shown to depolarize the V m by ~10 mV (Campbell et al, ). Thus, the mechanism identified here is likely applicable to other nonexcitable cell types where VGSCs are expressed (Chen et al, ; Grimes et al, ; House et al, ; Persson et al, ; Zhou et al, ). In addition, it has previously been shown that VGSCs contribute to steady‐state V m depolarization and viability in rat optic nerve axons and spinal cord astrocytes over a time course of hours (Sontheimer, Fernandez‐Marques, Ullrich, Pappas, & Waxman, ; Stys, Sontheimer, Ransom, & Waxman, ), suggesting that this mechanism persists over an extended period.…”

Chemical Synthesis, Proper Folding, Nav Channel Selectivity Profile and Analgesic Properties of the Spider Peptide Phlotoxin 1

“…A set of biophysical alterations in Na v 1.7 channel properties accompanies these pathologies, including changes in fast inactivation, the induction of persistent currents, and lower voltage thresholds for activation. Upregulation of Na v 1.7 is also associated with metastatic potential in prostate cancer in vivo and could therefore be used as a putative functional diagnostic marker [29,30]. Finally, Na v 1.7 may (i) have a role in the migration and cytokine responses of human dendritic cells [31]; (ii) help regulate neural excitability in vagal afferent nerves [32]; and (iii) contribute to odor perception in humans [33].…”