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Objective To investigate the effects of Compound Zhe Bei granule (CZBG) combined with doxorubicin on the expression of GST and Topo - Ⅱ in K562/A02 cell line multidrug resistance tumor xenografts in mice. Methods Tumor xenografts model was established by injecting the multidrug resistance cell line K562/A02 in the axillary flank of BALB/c - nu - nu mice. Drug - comgbination of CZBG intragastric administration and doxorubicin intraperitoneal injection ( i. p. ) was given to the BALB/c - nu nude mice. The tumor xenografts were made into slice after the dissection, and the expression of GST and Topo - Ⅱ in K562/A02 tumor xenografts in mice was investigated by immunohistochemical technique. The integral optical density (IOD) of GST and Topo- lⅡ in K562/A02 tumor xenografts was measured by Image ProPlus 6.0. Results Compared with the single treatment of doxorubicin i. p group,the combination of the doxorubicin and CZBG with dosage classified by three types( high, middle, low) can decrease IOD of GSH and Topo - Ⅱ in K562/A02 tumor xenografts with statistical significance( P
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Objective To explore the reversing mechanism of multidrug resistance of ciclosporin(CsA) on K562/A02 cell line,attenuating DNA damage repair through H2AX suppression.Methods K563 and K562/A02 respectively co-cultured with adriamycin(ADM) of different concentrations and CsA.MTT assay was employed to determine the inhibitory concentration of 50 percent(IC50),the resistance times and the reversal times.The K562/A02 cells treated with CsA,and reverse transcriptase(RT)-PCR technique was used to examine the mdr1 and H2AX mRNA level.Flow cytometry was used to measure P-glycoprotein(P-gp) and H2AX expression.Neutral comet assay was used to detect the level of DNA double strands break(DSBs) of the K562/A02 treated with ?H2AX antibody.Results 2?10-3g/L CsA could increase the sensitivity of K562/A02 to ADM,and the reversal times was 5.28.Mdr1 mRNA level and H2AX mRNA level were decreased when treated with CsA(P