An electrochemical method to assay the reversal effect on multi-drug resistance in tumor cells

Abstract

The occurrence of multi-drug resistance (MDR) has become a major obstacle to the successful performance of chemotherapy for cancer patients, so it is highly required to develop methods to assay the reversal effect on MDR in tumor cells. In this paper, we report a simple but efficient electrochemical method to assay the reversal effect on MDR by using limonin as reversal agent and multi-drug resistant leukemia cells K562/ADM as target cells. The strategy is based on the over-expression of P-glycoprotein (P-gp) in K562/ADM cells that may promote the efflux of the intracellular anticancer drug kaempferol. Consequently, kaempferol molecules accumulate outside the cells. They then adsorb onto the surface of the working electrode, which is modified by β-cyclodextrin/multi-walled carbon nanotubes (β-CD/MWCNTs), to give a well-defined electrochemical response. However, after K562/ADM cells have been incubated with the P-gp inhibitor limonin, efflux of the intracellular anticancer drug molecules will be prohibited, so the peak currents can be observed to decrease in a limonin concentration-dependent manner. Therefore, the proposed method in this work can efficiently characterize the reversal effect of limonin on MDR, which might have potential use in screening the reversal agents for cancer treatments in the future.