Ectopic ATP5B, which is located in a unique type of lipid raft caveolar structure, can be upregulated by cholesterol loading. As the structural component of caveolae, Cav-1 is a molecular hub that is involved in transmembrane signaling. In a previous study, the ATP5B-specific binding peptide B04 was shown to inhibit the migration and invasion of prostate cancer cells, and the expression of ATP5B on the plasma membrane of MDA-MB-231 cells was confirmed. The present study investigated the effect of ectopic ATP5B on the migration and invasion of MDA-MB-231 cells and examined the involvement of Cav-1. Cholesterol loading increased the level of ectopic ATP5B and promoted cell migration and invasion. These effects were blocked by B04. Ectopic ATP5B was physically colocalized with Cav-1, as demonstrated by double immunofluorescence staining and coimmunoprecipitation. After Cav-1 knockdown, the migration and invasion abilities of MDA-MB-231 cells were significantly decreased, suggesting that Cav-1 influences the function of ectopic ATP5B. Furthermore, these effects were not reversed after treatment with cholesterol. We concluded that Cav-1 may participate in MDA-MB-231 cell migration and invasion induced by binding to ectopic ATP5B.
Keywords: Breast cancer; Cav-1; Ectopic ATP5B; Invasion; Migration.