Single Molecular Localizations of Voltage-Gated Sodium Channel NaV1.5 on the Surfaces of Normal and Cancer Breast Cells

Voltage-gated sodium channels (VGSC) are widely expressed in various types of tumor and cancer cells, and Na V 1.5 are overexpression in highly metastatic breast cancer cells. There may be positive relations between the expression levels of Na V 1.5 and the breast cancer recurrence and metastasis. Herein, Na V 1.5 were detected and localized on the surfaces of normal and cancer breast cells by Single Molecular Recognition Imaging mode (SMRI) of Atomic Force Microscopy (AFM). The results reveal that Na V 1.5 were irregularly distributed on the surfaces of normal and cancer breast cells. The Na V 1.5 take an area percentage of 0.6% and 7.2% on normal and cancer breast cells, respectively, which indicates that there are more Na V 1.5 on cancer cells than normal cells. The specific interaction forces and binding kinetics between Na V 1.5-antibody complex system were investigated with Single Molecular Force Spectroscopy (SMFS) mode of AFM, indicating that the stability of the Na V 1.5-antibody on normal breast cells is higher than cancer breast cells. All these results will be useful to study the interactions of other ion channel-antibody systems, and will also be useful to understand the role of sodium channels in tumor metastasis and invasion.