Molecular Mechanisms Underlying Drug Resistance of the MCF7/ADR Breast Cancer Cell Line

Drug-sensitive MCF7 cells and drug-resistant MCF7/ADR cells are shown to differ with regard to the vimentin and P-gp expression levels, which is indicative of the coexistence of two drug resistance mechanisms in MCF7/ADR cells. The mesenchymal phenotype of epithelial cells makes a much greater contribution to the resistance mechanisms than the ABC transporter's overexpression, since the difference in the vimentin expression levels in drug-sensitive and drug-resistant cultures is significantly higher than the difference in the P-gp expression.