Abstract：Objective: To investigate the reversal effects of triptolide on drug resistance in doxorubicinresistant cells. Methods: Cell viability was measured by MTT assays. The K562/A02 cells were treated by triptolid at non-toxicity concentration. The apoptosis of cells were detected by Annexin V/PI methods.The expression of microRNA21 was measured by fluorescence quantitative polymerase chain reaction. Bcl-2 protein level were measured by western blot. After transfected with microRNA21 antisense oligonucleotide，the sensitivity to doxorubicin，the apoptosis of cells and Bcl-2 protein level were detected in K562/A02 cells. Results: Triptolide at non-toxicity concentration significantly enhanced sensitivity of K562/A02 cells to doxorubicin and promoted doxorubicin-induced apoptosis. Levels of microRNA21and Bcl-2 was significantly decreased after triptolide treatment. Transfection with microRNA21，a significant up-regulation of sensitivity to doxorubicin and a significant down-regulation of Bcl-2 protein was noted in K562/A02 cells. Conclusion: Triptolide significantly sensitizes K562/A02 cell to doxorubicin by inducing apoptosis and these effects of triptolide may be due to its down-regulation of microRNA21.
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2012, Vol. 22 
