[Effect of tetrandrine combined with daunorubicin on expressions of P21 and P-gp in K562/A02 cells].

This study was aimed to investigate the reversal effect of Tetrandrine (TET) combined with daunorubicin (DNR) on multidrug resistance (MDR) of K562/A02 cells and its relation to P21, P-gp and their genes so as to provide the new theoretic evidence for clinical use of TET. The experiments were divided into 4 groups: control group (DNR alone), combined 1 group (DNA+0.5 mg/L TET), combined 2 group (DNR+1.0 mg/L TET) and combined 3 group (DNR+2.0 mg/L TET). The expressions of P21, P-gp and mdr-1 gene in K562/A02 cells of different groups were detected by Western blot, flow cytometry and semi-quantitative PCR respectively. The results showed that the expression of P21 was enhanced along with increasing of TET concentration, the expression of P-gp was reduced along with increasing of TET concentration and expression of mdr-1 gene was almost not observed in K562 cells, but the high expression of mdr-1 gene was seen in K562/A02 cells, furthermore, the expression of mdr-1 gene in K562/A02 cells increasingly was reduced along with increasing of TET concentration. It is concluded that the TET possesses the reversal effect on multiple drug resistance of K562/A02 cells with concentration dependence, the reversal effect of TET may be related to up-regulation of P21 expression and down-regulation of P-gp and mdr-1 gene expressions in K562/A02 cells.