[Reversal of resistance to adriamycin in human breast cancer cell line MCF-7/ADM by beta-elemene].

OBJECTIVE

To study the reversal mechanism of adriamycin (ADM) resistance in human breast cancer cell line MCF-7/ADM by beta-elemene (beta-ELE), a wide spectrum anticancer drug derived from the Chinese herb Curcuma chaeocaulis.

METHODS

Sensitivity to ADM of MCF-7/ADM cells was studied by MTT assay. Intracellular accumulation of ADM in MCF-7/ADM cells was observed by fluorescent-spectrophotometry. Expression of bcl-2 protein was detected by flow cytometry.

RESULTS

A non-cytotoxic dose (6 micro g/ml) and a weakly cytotoxic dose (13 micro g/ml) of beta-ELE could significantly enhance the cytotoxic effects of ADM on MCF-7/ADM cells to 1.4 and 2.2 fold as compared to the beta-ELE untreated control cells. The intracellular concentration of ADM in MCF-7/ADM cells was significantly increased after treatment with beta-ELE (P < 0.01). The expression of bcl-2 protein in MCF-7/ADM cells was reduced from 90.2% to 70.0% (P < 0.05).

CONCLUSIONS

beta-ELE could partially reverse the drug resistance to ADM in MCF-7/ADM, which is related to the increased accumulation of intracellular ADM and the decreased expression of bcl-2.