The Triple-negative Breast Cancer Cell Line MDA-MB 231 Is Specifically Inhibited by the Ionophore Salinomycin

Abstract

Background/aim: Tumour cells of the profile CD44⁺/CD24^low/- have a high tumorigenic potential. Salinomycin can specifically inhibit the growth of these cells. Herein, we investigated the effects of salinomycin on the viability and migration of triple negative breast cancer cells.

Materials and methods: We analysed two cell lines: i) triple-negative MDA-MB 231 breast cancer cells and ii) a cytokeratin 18-transfected, re-differentiated subclone of the MDA-MB 231 cell line. The viability was determined using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) test, and the migration was determined using 24-h videography. The expression of oestrogen receptor was determined using immunohistochemistry.

Results: Salinomycin reduces all migration parameters in MDA-MB 231 cells. A significant correlation was found between increasing salinomycin concentrations and loss of cell viability, which was significantly less noticeable in the transfected control cells.

Conclusion: With salinomycin there is a specific inhibition of MDA-MB 231 cells. Since MDA-MB 231 has over 90% cells with the profile CD44⁺/CD24^low/-, these might represent a possible point of attack for salinomycin.

Keywords: Breast cancer; CSC; TNBC; ionophore; migration; motility; proliferation; salinomycin.