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

Abstract

Abstract Voltage-gated sodium channels (VGSC) are widely expressed in various types of tumor and cancer cells, and NaV1.5 are overexpression in highly metastatic breast cancer cells. There may be positive relations between the expression levels of NaV1.5 and the breast cancer recurrence and metastasis. Herein, NaV1.5 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 NaV1.5 were irregularly distributed on the surfaces of normal and cancer breast cells. The NaV1.5 take an area percentage of 0.6% and 7.2% on normal and cancer breast cells, respectively, which indicates that there are more NaV1.5 on cancer cells than normal cells. The specific interaction forces and binding kinetics between NaV1.5-antibody complex system were investigated with Single Molecular Force Spectroscopy (SMFS) mode of AFM, indicating that the stability of the NaV1.5-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.