Highexpression of snail leads to the P-gp modulateds MDR in breast cancer cell MCF-7

Aim: To explore the relationship between Snail and P-gp in breast cancer cell, and to reveal the effect of epithelial-mesenchymal transformation ( EMT) on the multidrug-resistance ( MDR ) of breast cancer cell. Methods: The eukaryotic expression vector pCD-NA3. 1-Snail was constructed, and then transfected into human breast cancer cell line MCF-7 to constuct MCF-7/Snail. Both cell lines MCF-7 and MCF-7/Snail were induced by adriamycin ( ADM ). Cell cytotoxicity assay and ADM efflux assay were used to measure the ability of drug resistance. The positive rate of P-gp of the two cell lines was detected by flow cytometry ; the mRNA of MDR1 and Snail was evaluated by real-time PCR. Results: MCF-7, the expression of MDR1 mRNA and Snail mRNA in MCF-7/Snail cell lines significantly increased ; the expression of P-gp was increased too ; the RR increased to 109. 2 ; fluorescence intensity intracellular was reduced to 7. 1. Conclusion: After transfected the eukaryotic expression vector, the capacity of MCF-7/Snail strongly increases compared with that of MCF-7.