Study Of The Reversal Effect Of Tanshinone ⅡA On Multidrug-resistance Of Breast Cancer Cell Line MCF-7/ADM

[Objective] It is main cause of chemotherapy nonsensitivity that primary and acquired drug resistance of malignant tumor cell are more than ninety percent. Among those, acquired multidrug resistance (MDR) is the research focus. The reverse of MDR can bring more practical value to clinical medicine. Verapamil, a calcium channel blocker, can increase the intracellular concentration of chemotherapy drug and reverse the multidrug resistance . But its side effect is severe. TanshinoneⅡA is a monomer of tanshinone which has been segregated and purified from Chinese herbal medicine Salvia miltiorrhiza. It was proved that tanshinoneⅡA can induce tumor cell differentiation, promote apoptosis and inhibt proliferation. But its mechanism is yet not clear. In research of cardiovascular, it was found having function of cell membrane calcium channel blocking. The purpose of this experiment is to investigate whether tanshinoneⅡA could reverse MDR like verapamil, and its reversal mechanism.[Methods] We study the change of sensitivity of breat cancer cell line MCF-7/ADM to ADM under intervention of tanshinoneⅡA. MTT assay to determin the cell growth inhibiting ratio of MCF-7, MCF-7/ADM andMCF-7/ADM intervented with tanshinoneⅡA by ADM, taking MCF-7 cellline as contro Flow cytometry to determine intracellular concentration ofADM of MCF-7/ADM, MCF-7/ADM intervented with tanshinoneⅡA 0.2μg/ml and 0.4μg/ml, comparing with that of MCF-7/ADM intervented withverapamil 5.0μmol/L and 10.0μmol/L. Statistical Analysis depends onSPSS11.5.[Results] The sensitivity of MCF-7/ADM to ADM is obviously lower thanthat of MCF-7. Intervented by tanshinoneⅡA, the sensitivity of MCF-7/AD-M to ADM was increasd and intracellular concentration of ADM waselevated also. TanshinoneⅡA with 0.2μg/ml can reverse MDR of MCF-7/ADM better. The reversal effect of tanshinoneⅡA is similar to that ofverapamil.[Conclusion] TanshinoneⅡA could reverse the multidrug-resistance ofMCF-7/ADM cell line,and its reversal mechanism might be inhibiting thefunction of P-glycoprotein.