Discovering the Triad between Nav1.5, Breast Cancer, and the Immune System: A Fundamental Review and Future Perspectives

Voltage-gated sodium channels in cancers

Voltage-gated sodium channels (VGSCs) initiate action potentials in electrically excitable cells and tissues. Surprisingly, some VGSC genes are aberrantly expressed in a variety of cancers, derived from "non-excitable" tissues that do not generate classic action potentials, showing potential as a promising pharmacological target for cancer. Most of the previous review articles on this topic are limited in scope, and largely unable to provide researchers with a comprehensive understanding of the role of VGSC in cancers. Here, we review the expression patterns of all nine VGSC α-subunit genes (SCN1A-11A) and their four regulatory β-subunit genes (SCN1B-4B). We reviewed data from the Cancer Genome Atlas (TCGA) database, complemented by an extensive search of the published papers. We summarized and reviewed previous independent studies and analyzed the VGSC genes in the TCGA database regarding the potential impact of VGSC on cancers. A comparison between evidence gathered from independent studies and data review was performed to scrutinize potential biases in prior research and provide insights into future research directions. The review supports the view that VGSCs play an important role in diagnostics as well as therapeutics of some cancer types, such as breast, colon, prostate, and lung cancer. This paper provides an overview of the current knowledge on voltage-gated sodium channels in cancer, as well as potential avenues for further research. While further research is required to fully understand the role of VGSCs in cancer, the potential of VGSCs for clinical diagnosis and treatment is promising.

Spider venom-derived peptide JZTX-14 prevents migration and invasion of breast cancer cells via inhibition of sodium channels

Nav1.5 channel is crucial for the proliferation and migration of breast cancer cells. In this study, we investigated the anticancer effect of JZTX-14, a natural peptide considered an effective antagonist of Nav1.5. First, we successfully isolated and purified the 31 amino acid peptide JZTX-14 containing three pairs of disulfide bonds from spider venom and synthesised JZTX-14 by solid phase synthesis. We then predicted their physiochemical properties and structures in the peptide database. Further, we investigated the effects of natural and synthetic JZTX-14 on the proliferation and migration of MDA-MB-231 breast cancer cells via modulation of sodium current through the Nav1.5 channel. The results showed that both synthetic and natural JZTX-14 inhibited Nav1.5 currents, indicating the successful synthesis of JZTX-14. However, JZTX-14 did not affect MDA-MB-231 cell proliferation but inhibited its migration. Transcriptome analysis revealed that JZTX-14 downregulated S100A4 and FBXO2 and upregulated SERPINB2 in MDA-MB-231 cells. Western blot analysis demonstrated an increased level of the epithelial marker, E-cadherin, and decreased levels of the mesenchymal markers, N-cadherin and vimentin, and matrix metalloproteinase (MMP2), indicating the possible underlying mechanism of the inhibition of MDA-MB-231 cell migration by JZTX-14. This study provides a new target for inhibiting breast cancer metastasis and identifies a potent natural peptide for treating Triple-negative breast cancer.